Tumours of Small & Large Bowel Quiz
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Questions and Answers

What is the main immunohistochemical marker used for identifying neuroendocrine tumors like carcinoid tumors?

  • Chromogranin (correct)
  • CD56
  • Ki67
  • Vimentin

    • Which of the following clinical features is specifically associated with carcinoid syndrome?

  • Gastrin secretion
  • Skin flushing (correct)
  • Hypoglycemia
  • Obstruction

    • What determines the grading of carcinoid tumors?

  • Size of the tumor
  • Number of mitoses and Ki67 percentage (correct)
  • Presence of liver metastasis
  • Level of serotonin production

    • Which tissue response is associated with neuroendocrine tumors (carcinoid tumors) in the body?

    <p>Desmoplastic response</p> Signup and view all the answers

    Where do most gastrointestinal stromal tumors (GISTS) primarily arise?

    <p>Stomach</p> Signup and view all the answers

    Which type of polyp is most commonly associated with an increased risk of developing gastrointestinal and non-gastrointestinal cancers?

    <p>Peutz-Jeghers polyps</p> Signup and view all the answers

    What is the primary characteristic of adenomatous polyps?

    <p>Composed of dysplastic epithelium</p> Signup and view all the answers

    What is the most significant risk factor for malignant transformation of adenomatous polyps?

    <p>Size greater than 2 cm</p> Signup and view all the answers

    Which type of polyp is characterized by cystically dilated glands within an inflamed stroma?

    <p>Juvenile polyps</p> Signup and view all the answers

    In patients with longstanding inflammatory bowel disease, which type of polyp is commonly observed?

    <p>Lymphoid polyp</p> Signup and view all the answers

    What differentiates sessile serrated lesions from hyperplastic polyps?

    <p>Serrated architecture in the crypt base</p> Signup and view all the answers

    How are non-neoplastic polyps primarily classified?

    <p>By their developmental origin</p> Signup and view all the answers

    Which syndrome is associated with multiple hamartomatous polyps and an increased risk of breast and thyroid cancers?

    <p>Cowden syndrome</p> Signup and view all the answers

    What is the typical clinical presentation of sessile serrated lesions?

    <p>May present with occult bleeding</p> Signup and view all the answers

    Which of the following polyps is most likely to be asymptomatic?

    <p>Hyperplastic polyps</p> Signup and view all the answers

    What is the primary genetic alteration linked to Familial Adenomatous Polyposis (FAP)?

    <p>Inactivation of the APC gene</p> Signup and view all the answers

    Which syndrome specifically includes a higher risk of brain tumors along with colorectal adenomatous polyps?

    <p>Turcot’s Syndrome</p> Signup and view all the answers

    What is the significance of the adenoma-carcinoma sequence in colorectal cancer development?

    <p>It suggests a direct correlation between the number of adenomas and cancer risk.</p> Signup and view all the answers

    Which hereditary syndrome is characterized by a defect in mismatch DNA repair genes and primarily affects the right side of the colon?

    <p>Lynch Syndrome</p> Signup and view all the answers

    Which population is primarily targeted for bowel screening using the Faecal Immunochemical Test (FIT)?

    <p>Adults aged 59 to 69 years</p> Signup and view all the answers

    What type of lesion is most commonly associated with the development of colorectal cancer in the adenoma-carcinoma sequence?

    <p>Adenomatous polyps</p> Signup and view all the answers

    What specific diagnostic tool is most effective for the visual assessment and biopsy of suspected colorectal cancer?

    <p>Colonoscopy</p> Signup and view all the answers

    Which genetic mutation is commonly associated with resistance to anti-EGFR therapy in metastatic colon cancer treatment?

    <p>KRAS</p> Signup and view all the answers

    Which of the following factors is NOT considered a risk factor for colorectal carcinoma?

    <p>High dietary fiber intake</p> Signup and view all the answers

    What is a characteristic clinical presentation of left-sided colorectal cancer?

    <p>Decreased stool calibre</p> Signup and view all the answers

    What type of biopsy is typically conducted to assess the adequacy of resection in colorectal cancer?

    <p>Colonoscopy biopsy</p> Signup and view all the answers

    Which test is frequently used as a surrogate marker for monitoring colorectal cancer recurrence after treatment?

    <p>Carcinoembryonic antigen (CEA)</p> Signup and view all the answers

    What is a characteristic of tumors located in the proximal colon?

    <p>They commonly present as polypoid lesions that may ulcerate.</p> Signup and view all the answers

    What is the most critical prognostic factor in colorectal cancer staging?

    <p>Depth of invasion (T stage)</p> Signup and view all the answers

    Which of the following is a non-neoplastic polyp found in the bowel?

    <p>Hyperplastic polyp</p> Signup and view all the answers

    Which of the following tumours of the bowel is classified as a mesenchymal neoplasm?

    <p>Leiomyoma</p> Signup and view all the answers

    Which polyp type is considered premalignant and most likely to progress to adenocarcinoma?

    <p>Villous adenoma</p> Signup and view all the answers

    What is the characteristic histology of juvenile polyps?

    <p>Cystically dilated glands in an inflamed stroma.</p> Signup and view all the answers

    Peutz-Jeghers syndrome is associated with which of the following? (Select all that apply)

    <p>Mucocutaneous pigmentation around lips and oral mucosa.</p> Signup and view all the answers

    Which syndrome is associated with the PTEN gene mutation?

    <p>Cowden syndrome</p> Signup and view all the answers

    In which of the following locations are hyperplastic polyps most commonly found?

    <p>Recto-sigmoid colon</p> Signup and view all the answers

    Which of the following polyps is associated with an increased risk of non-GI cancers?

    <p>Peutz-Jeghers polyps</p> Signup and view all the answers

    Which of the following is a feature of Cronkhite-Canada syndrome?

    <p>Hamartomatous polyps and nail atrophy</p> Signup and view all the answers

    Which of the following is a characteristic of inflammatory polyps?

    <p>They are formed from inflamed regenerative mucosa.</p> Signup and view all the answers

    How does a hyperplastic polyp differ from an adenomatous polyp?

    <p>Adenomatous polyps have a high malignant potential, whereas hyperplastic polyps have virtually none.</p> Signup and view all the answers

    Which of the following distinguishes Cowden syndrome from Cronkhite-Canada syndrome?

    <p>Cowden syndrome has a high risk of breast and thyroid cancer, while Cronkhite-Canada syndrome does not.</p> Signup and view all the answers

    Inflammatory (pseudo) polyps differ from lymphoid polyps in that inflammatory polyps are:

    <p>Caused by inflamed regenerative mucosa in response to long-standing inflammation.</p> Signup and view all the answers

    Peutz-Jeghers syndrome and juvenile polyposis syndrome both involve hamartomatous polyps, but Peutz-Jeghers syndrome is also associated with:

    <p>Mucocutaneous pigmentation and increased cancer risk.</p> Signup and view all the answers

    Which of the following is a key difference between juvenile polyps and hyperplastic polyps?

    <p>Juvenile polyps can be large and cystically dilated, while hyperplastic polyps are small and serrated.</p> Signup and view all the answers

    How does Peutz-Jeghers syndrome differ from juvenile polyposis syndrome?

    <p>Peutz-Jeghers syndrome presents with mucocutaneous pigmentation, while juvenile polyposis syndrome does not.</p> Signup and view all the answers

    Both Peutz-Jeghers and Cowden syndromes are associated with hamartomatous polyps, but Cowden syndrome also has:

    <p>A higher risk of breast and thyroid cancer.</p> Signup and view all the answers

    Juvenile polyps are usually seen in which age group?

    <p>Children &lt;5 years</p> Signup and view all the answers

    What is the main histological feature of a hyperplastic polyp?

    <p>Glands with goblet cell differentiation and serrated appearance</p> Signup and view all the answers

    In which condition do patients have an increased risk of thyroid and breast cancer along with multiple hamartomatous polyps?

    <p>Cowden Syndrome</p> Signup and view all the answers

    Which of the following has no malignant potential but increases the risk of other cancers such as pancreas, breast, and lung?

    <p>Peutz-Jeghers Syndrome</p> Signup and view all the answers

    Lymphoid polyps are composed of which of the following?

    <p>Intramucosal lymphoid tissue</p> Signup and view all the answers

    Which syndrome is characterized by hamartomatous polyps, nail atrophy, and skin pigmentation?

    <p>Cronkhite-Canada Syndrome</p> Signup and view all the answers

    What is the primary risk factor for malignancy in adenomatous polyps?

    <p>Size &gt;2cm, villous component, degree of dysplasia</p> Signup and view all the answers

    Which of the following is considered a pre-malignant polyp and a precursor to carcinoma?

    <p>Adenomatous polyp</p> Signup and view all the answers

    Which type of adenomatous polyp is most commonly pedunculated?

    <p>Tubular adenoma</p> Signup and view all the answers

    Which type of adenomatous polyp has the highest risk of malignant transformation?

    <p>Villous adenoma</p> Signup and view all the answers

    What distinguishes sessile serrated lesions from hyperplastic polyps?

    <p>Serrated architecture in the crypt base</p> Signup and view all the answers

    Adenomatous polyps with mild dysplasia typically present with which of the following symptoms?

    <p>Asymptomatic or occult bleeding</p> Signup and view all the answers

    What is the treatment for adenomatous polyps?

    <p>Complete excision</p> Signup and view all the answers

    Which factor correlates with the risk of malignancy in adenomatous polyps?

    <p>Histologic type and degree of dysplasia</p> Signup and view all the answers

    Which of the following conditions is associated with an almost 100% risk of developing colorectal carcinoma?

    <p>Familial Adenomatous Polyposis (FAP)</p> Signup and view all the answers

    What is the minimum number of adenomatous polyps required for a diagnosis of Familial Adenomatous Polyposis (FAP)?

    <p>100</p> Signup and view all the answers

    Which gene mutation is associated with Familial Adenomatous Polyposis (FAP)?

    <p>APC</p> Signup and view all the answers

    On which chromosome is the APC gene located?

    <p>5q21</p> Signup and view all the answers

    At what average age do patients typically begin to develop adenomatous polyps in Familial Adenomatous Polyposis (FAP)?

    <p>Teens to twenties</p> Signup and view all the answers

    Which of the following is a common complication associated with Familial Adenomatous Polyposis (FAP) due to polyp formation?

    <p>Bleeding and anemia</p> Signup and view all the answers

    Sessile serrated lesions are commonly found in which part of the gastrointestinal tract?

    <p>Right colon</p> Signup and view all the answers

    What histological feature is absent in sessile serrated lesions compared to adenomatous polyps?

    <p>Dysplastic epithelium</p> Signup and view all the answers

    Which of the following is a characteristic feature of sessile serrated lesions?

    <p>Lack of cytologic features of dysplasia</p> Signup and view all the answers

    What gene is mutated in Gardner's syndrome?

    <p>APC</p> Signup and view all the answers

    What type of inheritance pattern does Gardner's syndrome follow?

    <p>Autosomal dominant</p> Signup and view all the answers

    Which of the following is NOT a clinical feature of Gardner's syndrome?

    <p>Chronic pancreatitis</p> Signup and view all the answers

    Patients with Gardner's syndrome have an increased risk of which type of cancer?

    <p>Duodenal cancer</p> Signup and view all the answers

    What type of tumors are primarily associated with Turcot's syndrome?

    <p>Colorectal adenomatous polyps and brain tumors</p> Signup and view all the answers

    What is the genetic cause of Turcot's syndrome?

    <p>Mutations in the APC gene</p> Signup and view all the answers

    Which of the following brain tumors is commonly associated with Turcot's syndrome?

    <p>Both B and C</p> Signup and view all the answers

    What is the adenoma-carcinoma sequence?

    <p>The process of benign polyps evolving into malignant tumors</p> Signup and view all the answers

    Which statement about adenomatous polyps is true?

    <p>They can develop into colorectal cancer over time.</p> Signup and view all the answers

    What type of mutation is primarily associated with familial adenomatous polyposis (FAP)?

    <p>APC mutation (germline)</p> Signup and view all the answers

    Which of the following mutations leads to the activation of K-ras in the adenoma-carcinoma sequence?

    <p>Mutation of the APC gene</p> Signup and view all the answers

    What is the consequence of losing the DCC gene (located on chromosome 18q) in the adenoma-carcinoma sequence?

    <p>Promotion of tumor progression</p> Signup and view all the answers

    Which gene is associated with the loss of cell cycle regulation and is often mutated in colorectal cancer?

    <p>APC</p> Signup and view all the answers

    Which of the following is true regarding the activation of telomerase in the adenoma-carcinoma sequence?

    <p>It allows cancer cells to replicate indefinitely.</p> Signup and view all the answers

    Which chromosome is the K-ras gene located on? A) 5q B) 12p C) 17p D) 18q

    <p>12p</p> Signup and view all the answers

    The loss of which gene is associated with further progression from adenomatous polyps to colorectal carcinoma?

    <p>APC</p> Signup and view all the answers

    Which mutation typically occurs in the later stages of the adenoma-carcinoma sequence, often associated with invasive carcinoma?

    <p>p53 mutation</p> Signup and view all the answers

    Which of the following statements is true regarding the adenoma-carcinoma sequence?

    <p>Multiple genetic alterations are required for the progression from adenoma to carcinoma.</p> Signup and view all the answers

    What is the target population for bowel screening using the Faecal Immunochemical Test (FIT)?

    <p>60 to 69 years</p> Signup and view all the answers

    How often are individuals in the target population offered bowel screening?

    <p>Every 2 years</p> Signup and view all the answers

    What is the main aim of bowel screening programs?

    <p>To remove adenomatous polyps before progression to carcinoma</p> Signup and view all the answers

    What type of cancer is colon adenocarcinoma primarily associated with?

    <p>Disease of the western world</p> Signup and view all the answers

    Which of the following is a significant risk factor for colon adenocarcinoma?

    <p>Low fiber diet</p> Signup and view all the answers

    Which hereditary syndrome is characterized by numerous adenomatous polyps throughout the gastrointestinal tract?

    <p>Familial adenomatous polyposis (FAP)</p> Signup and view all the answers

    Which condition is most commonly associated with an increased risk of colon adenocarcinoma?

    <p>Inflammatory bowel disease (especially ulcerative colitis)</p> Signup and view all the answers

    What is the 'multi-hit' hypothesis in the context of colon adenocarcinoma?

    <p>The theory that colon adenocarcinoma results from cumulative genetic alterations</p> Signup and view all the answers

    Which genetic syndrome is primarily associated with germline mutations of the APC gene?

    <p>Familial adenomatous polyposis (FAP)</p> Signup and view all the answers

    In the adenoma-carcinoma sequence, which mutation typically occurs first?

    <p>Inactivation of APC gene</p> Signup and view all the answers

    Which of the following pathways is associated with microsatellite instability?

    <p>Both B and C</p> Signup and view all the answers

    What type of genetic alteration is primarily observed in hereditary nonpolyposis colorectal cancer (HNPCC)?

    <p>Microsatellite instability</p> Signup and view all the answers

    Which of the following best describes the relationship between adenomatous polyps and colon cancer in the adenoma-carcinoma sequence?

    <p>Some adenomatous polyps may progress to colon cancer through genetic alterations</p> Signup and view all the answers

    What type of inheritance pattern does Lynch syndrome (HNPCC) follow?

    <p>Autosomal dominant</p> Signup and view all the answers

    Which of the following is a key characteristic of colon cancer associated with Lynch syndrome?

    <p>It is usually right-sided.</p> Signup and view all the answers

    In Lynch syndrome type 1, what is the main associated cancer?

    <p>Colorectal cancer</p> Signup and view all the answers

    In Lynch syndrome type 2, which cancers have an increased risk along with colorectal cancer?

    <p>Ovarian and endometrial cancers</p> Signup and view all the answers

    Which of the following genes is associated with Lynch syndrome?

    <p>MSH2</p> Signup and view all the answers

    Patients with Lynch syndrome typically have:

    <p>A lower number of polyps than FAP</p> Signup and view all the answers

    Which of the following statements regarding Lynch syndrome is true?

    <p>Mismatch repair defects lead to microsatellite instability.</p> Signup and view all the answers

    A mutation in which of the following genes is most frequently associated with Lynch Syndrome?

    <p>MLH1</p> Signup and view all the answers

    Which of the following genes is part of the mismatch repair system and has an important role in Lynch Syndrome?

    <p>MLH6</p> Signup and view all the answers

    Which of the following describes the typical growth pattern of tumors in the proximal colon?

    <p>Polypoid lesions resembling 'cauliflower'</p> Signup and view all the answers

    What is a common clinical presentation associated with tumors in the proximal colon?

    <p>Iron deficiency anemia</p> Signup and view all the answers

    Which of the following statements is true regarding colorectal carcinoma in adults, especially males?

    <p>Iron deficiency anemia should be ruled out as a potential sign of colon cancer.</p> Signup and view all the answers

    In the distal colon, tumors tend to present as:

    <p>Annular, encircling lesions with 'napkin-ring' appearance</p> Signup and view all the answers

    What type of anemia is particularly associated with colorectal carcinoma in adults?

    <p>Iron deficiency anemia</p> Signup and view all the answers

    Why do tumors of the left side of the colon often present with obstruction?

    <p>The lumen is narrower compared to the right side and tumors tend to be annular.</p> Signup and view all the answers

    Which of the following is NOT a common symptom of colorectal cancer?

    <p>Increased appetite</p> Signup and view all the answers

    Which symptom is typically associated with left-sided colorectal carcinoma?

    <p>Decreased stool caliber and left lower quadrant pain</p> Signup and view all the answers

    Right-sided colorectal carcinoma is commonly associated with which of the following symptoms?

    <p>Iron deficiency anemia and vague abdominal pain</p> Signup and view all the answers

    Which of the following is a noted complication associated with colonic carcinoma?

    <p>Increased risk of Streptococcus bovis endocarditis</p> Signup and view all the answers

    What symptom might indicate a potential obstruction in left-sided colorectal cancer?

    <p>Decreased stool caliber</p> Signup and view all the answers

    Which of the following is a common symptom of left-sided colorectal carcinoma?

    <p>Decreased stool caliber</p> Signup and view all the answers

    What are the microscopic features of colorectal carcinoma?

    <p>Adenocarcinoma that can be well, moderately, or poorly differentiated</p> Signup and view all the answers

    Which of the following diagnostic methods is commonly used for colorectal carcinoma?

    <p>Colonoscopy and biopsy</p> Signup and view all the answers

    Which tumor marker is used in the management of colorectal cancer?

    <p>CEA (carcinoembryonic antigen)</p> Signup and view all the answers

    What does a low sensitivity and specificity of the CEA marker indicate?

    <p>It is not useful for early detection but may help assess resection adequacy and recurrence.</p> Signup and view all the answers

    Which of the following factors is associated with a poorer prognosis in colorectal carcinoma?

    <p>Invasive left-sided lesions</p> Signup and view all the answers

    What is a common site for metastasis in colorectal carcinoma?

    <p>Liver and lungs</p> Signup and view all the answers

    What factors can influence the prognosis of colorectal cancer?

    <p>Stage of the tumor, tumor grade, and genetic mutations</p> Signup and view all the answers

    Which microscopic feature is commonly associated with colorectal carcinoma?

    <p>Mucin production</p> Signup and view all the answers

    What does it indicate when colorectal carcinoma invades through the bowel wall?

    <p>The tumor has a more advanced stage and potentially worse prognosis.</p> Signup and view all the answers

    What is the primary purpose of measuring carcinoembryonic antigen (CEA) levels in colorectal cancer patients?

    <p>To assess the adequacy of resection and detect early recurrence</p> Signup and view all the answers

    What is a notable limitation of the CEA tumor marker?

    <p>It has low sensitivity and specificity.</p> Signup and view all the answers

    Which imaging technique is commonly used for staging colorectal cancer?

    <p>Radiology (CT or MRI)</p> Signup and view all the answers

    What does the 'T' in the TNM staging system for colorectal carcinoma primarily assess?

    <p>Depth of invasion of the tumor</p> Signup and view all the answers

    Which of the following is NOT included in the TNM classification for colorectal cancer?

    <p>L - Lymphatic spread</p> Signup and view all the answers

    What is the most common site for distant metastasis in colorectal carcinoma?

    <p>Liver</p> Signup and view all the answers

    Which of the following tests is used to assess mismatch repair proteins in colorectal cancer?

    <p>Immunohistochemistry</p> Signup and view all the answers

    What is the purpose of BRAF testing in colorectal carcinoma?

    <p>To assess the effectiveness of anti-EGFR therapy</p> Signup and view all the answers

    Which monoclonal antibody works by blocking the EGFR signaling pathway in metastatic colon cancer?

    <p>Both B and C</p> Signup and view all the answers

    What type of tumors do neuroendocrine tumors (carcinoids) primarily arise from?

    <p>Neuroendocrine cells</p> Signup and view all the answers

    Which of the following is a common site for carcinoid tumors?

    <p>Appendix</p> Signup and view all the answers

    What is a characteristic feature of carcinoid tumors when examined histologically?

    <p>Monotonous, speckled nuclei with abundant pink cytoplasm</p> Signup and view all the answers

    Which immunohistochemical marker is NOT associated with carcinoid tumors?

    <p>Estrogen receptor</p> Signup and view all the answers

    What is the primary purpose of performing immunohistochemistry in colorectal cancer? A) To assess tumor staging B) To detect mismatch repair protein deficiencies C) To identify distant metastasis D) To measure tumor grade

    <p>To detect mismatch repair protein deficiencies</p> Signup and view all the answers

    Which of the following mismatch repair proteins are commonly tested for using immunohistochemistry in colorectal cancer?

    <p>MLH1, MSH2, PMS1, MPS2</p> Signup and view all the answers

    Microsatellite instability (MSI) in colorectal cancer is commonly detected using which method?

    <p>Polymerase Chain Reaction (PCR)</p> Signup and view all the answers

    BRAF mutation testing is particularly important in colorectal cancer when:

    <p>Immunohistochemistry for mismatch repair proteins is deficient or MSI-High</p> Signup and view all the answers

    MLH1 promoter methylation is specifically tested when:

    <p>MSI is high or there is deficient MLH1 expression</p> Signup and view all the answers

    Microsatellite instability (MSI) in colorectal cancer is commonly detected using which method?

    <p>Polymerase Chain Reaction (PCR)</p> Signup and view all the answers

    BRAF mutation testing is particularly important in colorectal cancer when:

    <p>Immunohistochemistry for mismatch repair proteins is deficient or MSI-High</p> Signup and view all the answers

    MLH1 promoter methylation is specifically tested when:

    <p>MSI is high or there is deficient MLH1 expression</p> Signup and view all the answers

    Which of the following monoclonal antibodies is used to block the EGFR signaling pathway in metastatic colon cancer?

    <p>Cetuximab</p> Signup and view all the answers

    Panitumumab and cetuximab are effective in treating metastatic colon cancer by inhibiting which signaling pathway?

    <p>EGFR</p> Signup and view all the answers

    Which of the following mutations is associated with resistance to anti-EGFR therapy in metastatic colon cancer?

    <p>KRAS</p> Signup and view all the answers

    The effectiveness of anti-EGFR monoclonal antibodies such as cetuximab and panitumumab depends on the mutation status of which of the following genes?

    <p>BRAF, KRAS, and NRAS</p> Signup and view all the answers

    Which monoclonal antibody is used to block the growth of blood vessels in metastatic colon cancer by inhibiting VEGF?

    <p>Bevacizumab</p> Signup and view all the answers

    Which mechanism of action is associated with the drug bevacizumab in metastatic colon cancer treatment?

    <p>Blocks VEGF signaling</p> Signup and view all the answers

    In patients with metastatic colon cancer, mutations in which gene predict resistance to treatment with cetuximab and panitumumab?

    <p>KRAS</p> Signup and view all the answers

    Cetuximab and panitumumab are NOT effective in patients with metastatic colon cancer who have mutations in which of the following genes?

    <p>NRAS</p> Signup and view all the answers

    Which of the following monoclonal antibodies is specifically designed to inhibit VEGF and block angiogenesis in metastatic colon cancer?

    <p>Bevacizumab</p> Signup and view all the answers

    Which of the following is TRUE about the use of monoclonal antibodies in colorectal cancer treatment?

    <p>Bevacizumab works by inhibiting the formation of blood vessels in tumors.</p> Signup and view all the answers

    Which of the following is the most common site for neuroendocrine (carcinoid) tumors in the gastrointestinal tract?

    <p>Small bowel</p> Signup and view all the answers

    Carcinoid syndrome is most likely to occur when neuroendocrine tumors have metastasized to which of the following organs?

    <p>Liver</p> Signup and view all the answers

    Which of the following hormones is most commonly secreted by neuroendocrine (carcinoid) tumors?

    <p>Serotonin</p> Signup and view all the answers

    What is the histological feature commonly observed in neuroendocrine (carcinoid) tumors?

    <p>Monotonous, speckled nuclei with abundant pink cytoplasm</p> Signup and view all the answers

    Which of the following immunohistochemical markers is most commonly positive in neuroendocrine (carcinoid) tumors?

    <p>Chromogranin</p> Signup and view all the answers

    Which of the following is a common symptom of carcinoid syndrome?

    <p>Flushing</p> Signup and view all the answers

    Carcinoid syndrome is associated with elevated levels of which substance in the urine?

    <p>5-hydroxyindoleacetic acid (5-HIAA)</p> Signup and view all the answers

    Which clinical feature is NOT typically associated with carcinoid syndrome?

    <p>Hematuria</p> Signup and view all the answers

    What pathological feature is commonly seen in neuroendocrine (carcinoid) tumors?

    <p>Desmoplastic response</p> Signup and view all the answers

    Which of the following is TRUE regarding the grading of neuroendocrine (carcinoid) tumors?

    <p>Higher grade tumors have more mitotic figures and a higher Ki67 proliferation index</p> Signup and view all the answers

    Which of the following is TRUE regarding the grading of neuroendocrine (carcinoid) tumors?

    <p>Higher grade tumors have more mitotic figures and a higher Ki67 proliferation index</p> Signup and view all the answers

    Which of the following conditions can be caused by neuroendocrine tumors releasing excessive gastrin?

    <p>Zollinger-Ellison syndrome</p> Signup and view all the answers

    Which of the following triggers symptoms of carcinoid syndrome?

    <p>Alcohol or emotional stress</p> Signup and view all the answers

    Which of the following growth patterns is NOT typically seen in neuroendocrine (carcinoid) tumors?

    <p>Papillary structures</p> Signup and view all the answers

    What is the significance of the dense-core granules seen in neuroendocrine tumors?

    <p>They are involved in the secretion of hormones and neuropeptides.</p> Signup and view all the answers

    Which of the following is a common microscopic reaction seen in response to neuroendocrine (carcinoid) tumors?

    <p>Desmoplastic reaction</p> Signup and view all the answers

    Which staining technique is commonly used to identify neuroendocrine (carcinoid) tumors?

    <p>Immunohistochemistry for chromogranin and synaptophysin</p> Signup and view all the answers

    Which of the following is the most common site for neuroendocrine (carcinoid) tumors in the gastrointestinal (GI) tract?

    <p>Appendix</p> Signup and view all the answers

    Neuroendocrine (carcinoid) tumors are associated with the secretion of which bioactive hormone, particularly contributing to carcinoid syndrome?

    <p>Serotonin</p> Signup and view all the answers

    What is a key factor that correlates with the behavior and malignancy potential of neuroendocrine (carcinoid) tumors?

    <p>Size, location, and depth of penetration</p> Signup and view all the answers

    Which of the following best describes the malignant potential of neuroendocrine (carcinoid) tumors?

    <p>They are low-grade malignant tumors with potential for local invasion and metastasis.</p> Signup and view all the answers

    Which of the following GI sites has the least likelihood of developing neuroendocrine (carcinoid) tumors?

    <p>Esophagus</p> Signup and view all the answers

    Which of the following is a requirement for the development of carcinoid syndrome in gastrointestinal (GI) carcinoid tumors?

    <p>Metastasis to the liver</p> Signup and view all the answers

    Carcinoid syndrome is characterized by the excess elaboration of which substance?

    <p>Serotonin (5-HT)</p> Signup and view all the answers

    Which of the following is NOT a symptom of carcinoid syndrome?

    <p>Hypotension</p> Signup and view all the answers

    Carcinoid syndrome leads to systemic fibrosis, particularly affecting which cardiac structures?

    <p>Pulmonary and tricuspid valves</p> Signup and view all the answers

    Which of the following can trigger the symptoms of carcinoid syndrome?

    <p>Alcohol or emotional stress</p> Signup and view all the answers

    In carcinoid syndrome, where is serotonin primarily degraded, preventing the syndrome from developing in the absence of liver metastasis?

    <p>Liver</p> Signup and view all the answers

    A patient with carcinoid syndrome presents with hepatomegaly. What is the most likely cause of the enlarged liver?

    <p>Hepatic metastasis of the carcinoid tumor</p> Signup and view all the answers

    Gastrointestinal stromal tumors (GISTs) arise from which type of cells in the gastrointestinal tract?

    <p>Pacemaker cells (Interstitial cells of Cajal)</p> Signup and view all the answers

    Which of the following genetic mutations is commonly associated with gastrointestinal stromal tumors (GISTs)?

    <p>c-kit proto-oncogene mutation</p> Signup and view all the answers

    What is the first-line targeted therapy for gastrointestinal stromal tumors (GISTs) with c-kit or PDGFRA mutations?

    <p>Imatinib (Gleevec)</p> Signup and view all the answers

    Which of the following immunohistochemistry markers is positive in gastrointestinal stromal tumors (GISTs)?

    <p>CD117 (c-Kit)</p> Signup and view all the answers

    Which of the following is a risk factor for B-cell gastric lymphoma (MALTOMA)?

    <p>H. pylori infection</p> Signup and view all the answers

    In the context of gastrointestinal lymphoma, what is the immunohistochemistry marker commonly associated with B-cell lymphoma?

    <p>CD20</p> Signup and view all the answers

    Coeliac disease is a known risk factor for which type of gastrointestinal lymphoma?

    <p>T-cell lymphoma</p> Signup and view all the answers

    Which of the following secondary tumors can metastasize to the gastrointestinal tract? (Select all that apply)

    <p>Ovarian tumors</p> Signup and view all the answers

    Which of the following features is used to classify gastrointestinal stromal tumors (GISTs) as benign or malignant?

    <p>Size, site, and mitotic count</p> Signup and view all the answers

    Which of the following is NOT commonly a location for gastrointestinal stromal tumors (GISTs)?

    <p>Esophagus</p> Signup and view all the answers

    Gastrointestinal lymphoma associated with coeliac disease primarily involves which part of the bowel?

    <p>Proximal bowel</p> Signup and view all the answers

    Which of the following is true regarding mesenchymal tumors of the gastrointestinal tract?

    <p>Leiomyomas are benign smooth muscle tumors</p> Signup and view all the answers

    Which of the following immunohistochemistry markers would confirm a diagnosis of lymphoma?

    <p>CD45</p> Signup and view all the answers

    Which type of gastrointestinal lymphoma is most commonly associated with Helicobacter pylori infection?

    <p>MALT lymphoma (MALTOMA)</p> Signup and view all the answers

    What is the most common primary extranodal site for lymphoma?

    <p>Gastrointestinal tract</p> Signup and view all the answers

    Immunohistochemistry for gastrointestinal lymphomas shows CD3 positivity. Which type of lymphoma does this indicate?

    <p>T-cell lymphoma</p> Signup and view all the answers

    Which of the following is a monoclonal antibody that targets vascular endothelial growth factor (VEGF) to inhibit angiogenesis in metastatic colon cancer?

    <p>Bevacizumab (Avastin)</p> Signup and view all the answers

    What is the key role of KRAS, BRAF, and NRAS mutation testing in metastatic colon cancer treatment?

    <p>To predict resistance to EGFR inhibitors</p> Signup and view all the answers

    Which of the following is NOT a common secondary tumor that metastasizes to the gastrointestinal tract?

    <p>Hepatocellular carcinoma</p> Signup and view all the answers

    Which of the following markers is most commonly associated with B-cell lymphomas?

    <p>CD20</p> Signup and view all the answers

    CD3 is a specific marker for which type of lymphoma?

    <p>T-cell lymphoma</p> Signup and view all the answers

    CD79 is a marker for which type of lymphocytes?

    <p>B cells</p> Signup and view all the answers

    Which of the following immunohistochemical markers distinguishes B-cell lymphoma from T-cell lymphoma?

    <p>CD79</p> Signup and view all the answers

    Which of the following mutations is commonly associated with Gastrointestinal Stromal Tumors (GISTs)?

    <p>c-kit proto-oncogene</p> Signup and view all the answers

    Which of the following drugs is used to inhibit tyrosine kinase activity in GIST patients with c-kit or PDGFRA mutations?

    <p>Gleevec (imatinib)</p> Signup and view all the answers

    Which of the following immunohistochemistry markers is commonly positive in Gastrointestinal Stromal Tumors (GISTs)?

    <p>CD117</p> Signup and view all the answers

    DOG1 is a diagnostic marker for which type of tumor?

    <p>GISTs</p> Signup and view all the answers

    Which of the following mutations is often associated with resistance to Gleevec (imatinib) in GIST treatment?

    <p>PDGFRA</p> Signup and view all the answers

    What is the function of the drug Gleevec (imatinib) in the treatment of GISTs?

    <p>Blocks tyrosine kinase activity</p> Signup and view all the answers

    Which two mutations are commonly implicated in the pathogenesis of GISTs?

    <p>c-kit and PDGFRA</p> Signup and view all the answers

    Which gene mutation is most commonly associated with Gastrointestinal Stromal Tumors (GISTs)?

    <p>c-kit (CD117)</p> Signup and view all the answers

    Which immunohistochemical marker is used for diagnosing GISTs?

    <p>CD117</p> Signup and view all the answers

    Study Notes

    Tumours of Small & Large Bowel

    • Tumours of the large bowel are more common than tumours of the small bowel.
    • Primary tumours include non-neoplastic polyps, epithelial neoplasms, mesenchymal neoplasms and lymphoma.
    • Secondary tumours are rare.

    Polyps

    • Polyps are masses arising from the mucosal epithelium or from the submucosal connective tissue protruding into the lumen of the gut.
    • Polyps can be non-neoplastic or neoplastic (adenomas).
    • Polyps can be pedunculated (with a stalk) or sessile (flat).

    Non-Neoplastic Polyps

    • Non-neoplastic polyps include hyperplastic polyps, hamartomatous polyps (juvenile, Peutz-Jeghers), inflammatory polyps and lymphoid polyps.

    Hyperplastic Polyps

    • Common lesions, found in over 50% of people over 60 years.
    • Often found in the recto-sigmoid.
    • Less than 5 mm in size.
    • Can be single or multiple.
    • Usually asymptomatic.
    • Composed of non-neoplastic glands, with goblet cell differentiation and serrated appearance.
    • Result from delayed shedding of surface epithelial cells.
    • Virtually no malignant potential.

    Juvenile Polyps

    • Hamartomatous malformations of bowel mucosa.
    • Common in children under 5 years but can be found in adults.
    • Usually located in the rectum.
    • Can be large (1-3 cm).
    • Contain cystically dilated glands in an inflamed stroma.
    • No malignant potential.
    • Juvenile polyposis is characterized by multiple juvenile polyps and adenomas.

    Peutz-Jeghers Polyps

    • Hamartomatous polyps of the small intestine and colon.
    • Can be single or multiple (Peutz-Jeghers syndrome).
    • Characterized by mucocutaneous pigmentation (around lips, oral mucosa, genitalia and palmar surfaces of the hand).
    • Multiple hamartomatous polyps throughout the gastrointestinal tract.
    • No malignant potential.
    • Increased risk of developing GI and non-GI cancers (pancreas, breast, lung, ovary and uterus).
    • Autosomal dominant syndrome.
    • Comprise glands and connective tissue with smooth muscle.

    Hamartomatous Syndromes

    • Cowden syndrome: Autosomal dominant syndrome (PTEN). Characterized by multiple hamartomatous polyps, trichoepitheliomas and increased risk of thyroid and breast cancer.
    • Cronkhite-Canada syndrome: Characterized by hamartomatous polyps, nail atrophy, skin pigmentation and increased risk of GI cancers.

    Inflammatory and Lymphoid Polyps

    • Inflammatory (pseudo) polyps: Inflamed regenerative mucosa surrounded by ulcerated tissue, seen in patients with long-standing inflammatory bowel disease.
    • Lymphoid polyps: Intramucosal lymphoid tissue.

    Adenomatous Polyps = Neoplastic Polyps

    • Common lesions (prevalence 50% at age of 60).
    • Proliferation of dysplastic epithelium (ranging from mild to severe).
    • Precursors of carcinoma.
    • Benign but may progress to adenocarcinoma via the adenoma-carcinoma sequence.

    Adenomatous Polyps

    • Three types: tubular, villous and tubulovillous.
    • Can be pedunculated or sessile.
    • All adenomatous polyps are covered by dysplastic epithelium.
    • Risk of malignancy correlates with size (>2cm), histologic type (villous component) and degree of dysplasia.
    • All adenomatous polyps should be removed.
    • May be asymptomatic.
    • May present with occult bleeding, anaemia, protein loss and obstruction.
    • Treatment involves complete excision.

    Sessile Serrated Lesions

    • Overlap with hyperplastic polyps, but have serrated architecture in the crypt base.
    • Lack cytologic features of dysplasia.
    • Found in the right colon.
    • May be asymptomatic.
    • May present with occult bleeding, anaemia, protein loss and obstruction.
    • Treatment involves complete excision.

    Familial Adenomatous Polyposis (FAP)

    • Autosomal dominant inheritance.
    • Mutations of APC gene on 5q21.
    • Numerous adenomatous polyps throughout the gastrointestinal tract, especially in the large bowel (minimum 100, may be >2000).
    • Average age of onset of polyps is teens to twenties, presenting with bleeding and anaemia.
    • Virtually 100% risk of carcinoma within 10 to 15 years.
    • Indication for prophylactic total colectomy.

    Gardner’s Syndrome

    • A variation of FAP.
    • Mutations of APC gene.
    • Autosomal dominant.
    • Characterized by multiple adenomas, epidermoid cysts (skin), fibromatosis (soft tissue), osteomas (bone) and abnormal dentition (teeth).
    • Increased risk of duodenal cancer and thyroid cancer.

    Turcot’s Syndrome

    • A variation of FAP.
    • Mutations of APC gene.
    • Autosomal dominant.
    • Characterized by colorectal adenomatous polyps and brain tumours (gliomas, medulloblastoma).

    Adenoma-Carcinoma Sequence

    • Describes the development of carcinoma from adenomatous lesions.
    • Populations with a high prevalence of adenomas also have a high prevalence of colorectal cancer.
    • Distribution of adenomas is comparable to that of colorectal cancer.
    • Peak incidence of adenomatous polyps precedes the peak for cancer by some years.
    • Risk of cancer is related to the number of adenomas.
    • Adenomatous lesions are often seen in association with invasive carcinoma.
    • Involves APC mutations (FAP-germline, Adenoma-sporadic), inactivation/mutation of other allele of APC, activation of K-ras (12p), loss of DCC gene (18q), loss of p53 (17p), increase expression of COX and activation of telomerase.

    Bowel Screen

    • Target population: 59 to 69 years.
    • Screened every 2 years.
    • Screening conducted using a home testing kit (Faecal Immunochemical Test- FIT).
    • Polyps are usually clinically silent, but can bleed.
    • Aim is to remove adenomatous polyps before progression to carcinoma (colonoscopy).
    • All polyps are removed and examined microscopically.

    Colon Adenocarcinoma

    • Disease of the Western world.
    • Peak incidence is in the seventh decade.
    • Carcinoma in a young person is associated with genetic predisposition or ulcerative colitis.

    Risk Factors for Colon Carcinoma

    • Increasing age
    • Adenomatous polyps
    • Hereditary syndromes
    • Inflammatory bowel disease (especially ulcerative colitis)
    • Diet (low fibre, high fat, high carbohydrates, high intake of red meat and decreased intake of micronutrients, vitamins A,C & E)
    • Obesity
    • Physical inactivity

    Hereditary Colon Cancer Syndromes

    • Familial adenomatous polyposis
    • Hereditary nonpolyposis colorectal cancer (HNPCC)

    Colon Adenocarcinoma-Cumulative Genetic Alterations or “Multi-Hit” Hypothesis

    • Two pathways:
      • Adenoma-carcinoma sequence: APC mutations (FAP-germline, Adenoma-sporadic).
      • Microsatellite instability (HNPCC, serrated lesions).

    Lynch Syndrome

    • HNPCC (Lynch syndrome).
    • Autosomal dominant familial syndrome.
    • Colonic cancer is not associated with pre-existing adenomas and is usually right-sided.
    • Lower number of polyps than FAP.
    • Defect in the mismatch DNA repair genes (MSH2, MLH1, MLH6, PMS1, MPS2).
    • Lynch syndrome 1: Increased risk of colon cancer.
    • Lynch syndrome 2: Increased risk of colon cancer and non-GI cancers (endometrial, ovarian).

    Colorectal Carcinoma

    • Tumours in the proximal colon tend to grow as polypoid lesions ("cauliflower"), may ulcerate resulting in occult bleeding.
    • Iron deficiency anaemia in an adult (especially a male) should be considered colon cancer until proven otherwise.
    • In the distal colon, tumours tend to be annular, encircling lesions ("napkin-ring") causing constriction with symptoms and signs of obstruction (rectal bleeding and changing bowel habits).

    Why Do Tumours of the Left Side Present with Obstruction?

    • Annular tumours.
    • Lumen is narrower than the right side.
    • Solid faecal material.

    Symptoms of Colorectal Cancer

    • Change in bowel habits.

    • Blood in stool.

    • Iron deficiency anaemia.

    • Abdominal discomfort/pain.

    • Colonic carcinoma is associated with an increased risk of Streptococcus bovis endocarditis.

    Clinical Presentation of Colorectal Cancer

    • Left-sided carcinoma: Decreased stool calibre, left lower quadrant pain, blood-streaked stool.
    • Right-sided carcinoma: Iron deficiency anaemia and vague pain.

    Microscopic Features of Colorectal Carcinoma

    • Adenocarcinoma: Well, moderately or poorly differentiated.
    • May produce mucin.
    • Invade through the bowel wall.
    • Metastasise to lymph nodes and then to liver and lungs.

    Diagnosis of Colorectal Carcinoma

    • Colonoscopy and biopsy.
    • Barium enema.
    • Occult blood.
    • Digital rectal examination.
    • CEA (carcinoembryonic antigen- tumour marker).
      • Low sensitivity and specificity.
      • Used to assess the adequacy of resection and detect early recurrence.
    • Radiology-staging.

    Prognosis of Colorectal Carcinoma

    • Stage of the tumour.
    • Tumour grade (degree of differentiation).
    • Tumour location:
      • Left sided lesions have a poorer prognosis because they tend to be more invasive.
    • Adequacy of excision (margins).
    • Genetic mutations and MSI.

    Staging- Most Important Prognostic Factor-TNM

    • T: Depth of invasion; tumours limited to the mucosa generally do not spread due to a lack of lymphatics in the mucosa.
    • N: Spread to regional nodes.
    • M: Distant spread; most commonly involves the liver.

    Ancillary Tests

    • Immunohistochemistry for mismatch repair proteins (MSH2, MLH1, PMS1, MPS2).
    • MSI by PCR.
    • Gene mutation testing: KRAS, NRAS, BRAF.
      • BRAF testing (if IHC deficient or MSI-High).
      • MLH1 promoter methylation (if MSI high or deficient MLH1).

    Monoclonal Antibodies Approved to Treat Metastatic Colon Cancer

    • Erbitux® (cetuximab) and Vectibix® (panitumumab): Block the EGFR signalling pathway.
      • Effectiveness of EGFR inhibition depends on downstream mutations.
      • KRAS, BRAF, NRAS mutations are associated with resistance to anti-EGFR therapy.
    • Avastin® (bevacizumab): Blocks the growth of blood vessels to the tumour.

    Neuroendocrine Tumours (Carcinoid)

    • Tumours of neuroendocrine cells.
    • Present throughout the gastrointestinal tract.
    • Most common sites: appendix, small bowel, rectum, stomach, colon.
    • May secrete numerous bioactive hormones (especially serotonin).
    • Low grade malignant tumours.
    • Behaviour correlates with size, location and depth of penetration.

    Neuroendocrine Tumours (Carcinoid)- Pathology

    • Solitary or multicentric firm, yellow-tan nodules.
    • Usually submucosal masses, sometimes with ulceration.
    • Cause striking desmoplastic response.
    • Form islands, trabeculae, glands or sheets.
    • Monotonous, speckled nuclei and abundant pink cytoplasm.
    • Contain cytoplasmic secretory dense-core granules.

    Immunohistochemistry Carcinoid Tumours

    • Chromogranin
    • Synaptophysin
    • CD56
    • Proliferation index Ki67

    Grade Carcinoid Tumours (Neuroendocrine Tumours)

    • Grade 1, 2, 3 - depending on number of mitoses and Ki67%.

    Clinical Features of Carcinoid Tumours

    • Asymptomatic.

    • Obstruction.

    • Bleeding.

    • May release their products into circulation.

      • Zollinger-Ellison syndrome (Gastrin).
      • Cushing syndrome (adrenocorticotropic hormone).
      • Hypoglycemia (insulin).

    • Carcinoid syndrome: Production of serotonin.

    Carcinoid Syndrome

    • Seen only with massive liver metastases (5-HT is degraded in the liver).

    • Hepatic metastasis not required for extra-GI carcinoids.

    • Excess elaboration of serotonin, detected in blood and urine.

    • Symptoms:

      • Vasomotor disturbances (skin flushing).
      • Intestinal hypermotility (diarrhoea/cramps).
      • Bronchospasm (wheezing, cough).
      • Systemic fibrosis (with cardiac involvement, right ventricular subendocardial fibrosis, pulmonary and tricuspid valve).
      • Hepatomegaly (metastasis).

    • Symptoms can be triggered by alcohol or emotional stress.

    Mesenchymal Tumours

    • Benign: lipoma, leiomyoma, schwannoma.
    • Gastrointestinal stromal tumours (GISTs).

    Gastrointestinal Stromal Tumours (GISTS)

    • Mesenchymal neoplasms of the gastrointestinal tract.
    • Arise from the pacemaker cells of the GIT (Interstitial cells of Cajal - ICC).
    • 2/3 in the stomach.
    • 25% in the small intestine.

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    Description

    Test your knowledge on the tumours of the small and large bowel, including the types of polyps and their classifications. This quiz covers non-neoplastic and neoplastic polyps, as well as the prevalence and characteristics of these lesions. Perfect for medical students and professionals looking to reinforce their understanding of gastrointestinal pathology.

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