Neoplasia

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Questions and Answers

What is the term for the study of tumors?

Oncogenesis

Tumorigenesis

Oncology (correct)

Neoplasia

What is the primary difference between benign and malignant tumors?

Size of the tumor

Type of cells involved

Ability to spread to distant sites (correct)

Location of the tumor

What is the term for a tumor that results from a transformed epithelial cell that produces a gland-like structure?

Chondroma

Papilloma

Fibroma

Adenoma (correct)

What is the term for a disorganized tissue that resembles the tissue at the site of origin?

Hamartoma Signup and view all the answers

What is the term for a tumor that is composed of parenchyma and stroma?

All of the above Signup and view all the answers

What is the term for a tumor that grows into a finger-like projection?

Papilloma Signup and view all the answers

What is the term for a tumor that arises from cartilage?

Chondroma Signup and view all the answers

What is the term for a tumor that originates from a different location than the tissue of origin?

Choristoma Signup and view all the answers

What is the term for a hollow cystic mass that is common in the ovary?

Cystadenoma Signup and view all the answers

What is the term for a type of mixed tumor containing cells from all three germ layers?

Teratoma Signup and view all the answers

Which type of neoplasm affects the lymph nodes and extranodal sites?

Lymphoma Signup and view all the answers

What is the most common salivary gland tumor?

Pleomorphic adenoma Signup and view all the answers

What is the term for a malignancy of melanocytes seen in the skin and oral cavity?

Melanoma Signup and view all the answers

What is the term for a malignancy of pleural tissue?

Mesothelioma Signup and view all the answers

What is the term for a type of tumor that arises from cells of mesenchymal origin?

Sarcoma Signup and view all the answers

What is the term for a malignancy of testicular tissue?

Seminoma Signup and view all the answers

What is the term for a type of tumor that arises from epithelial cells?

Carcinoma Signup and view all the answers

What is the primary characteristic that distinguishes malignant neoplasms from benign neoplasms?

Infiltration and destruction of underlying structures Signup and view all the answers

What is the term for the spread of a tumor to a distant site?

Metastasis Signup and view all the answers

What is the term for a change in the size and shape of cells and their nuclei?

Pleomorphism Signup and view all the answers

What is the term for the process by which cancer cells break away from the primary tumor and enter the bloodstream?

Hematogenous spread Signup and view all the answers

What is the term for the first node that receives lymph from a primary tumor?

Sentinel lymph node Signup and view all the answers

What is the term for the loss of differentiation of cells, resulting in a more primitive appearance?

Anaplasia Signup and view all the answers

What is the term for the process by which cancer cells spread to lymph nodes and other lymphatic tissues?

Lymphatic spread Signup and view all the answers

What is the term for a change in the shape and size of the nucleus, resulting in a darkly staining nucleus?

Hyperchromatism Signup and view all the answers

What is the term for a tumor that is confined to the entire epithelial layer and has not invaded into the underlying connective tissue?

Carcinoma in situ Signup and view all the answers

Which of the following chronic inflammatory disorders is associated with esophageal adenocarcinoma?

Barrett esophagus Signup and view all the answers

What is the primary function of tumor suppressor genes?

To prevent uncontrolled growth and induce apoptosis Signup and view all the answers

Which of the following genes is commonly affected in cancers and is a tumor suppressor gene?

TP53 Signup and view all the answers

What is the result of a translocation between chromosomes 9 and 22 in chronic myeloid leukemia?

Fusion of the ABL gene with the BCR gene Signup and view all the answers

Which of the following is a characteristic of oncogenes?

They promote cell growth and proliferation Signup and view all the answers

What is the result of a deletion of a tumor suppressor gene on chromosome 13q14?

Retinoblastoma Signup and view all the answers

Which of the following is a type of genetic mutation that can contribute to cancer development?

All of the above Signup and view all the answers

What is the role of microRNAs in cancer formation?

To reduce the activity of protein and inhibit gene expression Signup and view all the answers

Which of the following is a characteristic of aneuploidy?

A chromosome number that is not a multiple of 23 Signup and view all the answers

What is the result of the fusion of the BCR gene on chromosome 22 with the ABL gene on chromosome 9?

The development of chronic myeloid leukemia Signup and view all the answers

What is the role of p53 protein in the cell cycle?

To induce cell quiescence and apoptosis in response to DNA damage Signup and view all the answers

What is the Warburg effect in cancer cells?

The increased fermentation of glucose to lactate even in the presence of oxygen Signup and view all the answers

What is the role of transforming growth factor-β (TGF-β) in cancer?

To inhibit cell proliferation and induce apoptosis Signup and view all the answers

What is the function of E-cadherin in cell adhesion?

To regulate cell-cell adhesion and maintain tissue architecture Signup and view all the answers

What is the role of the RB gene in the cell cycle?

To regulate the G1-S checkpoint and induce quiescence Signup and view all the answers

What is the result of a mutation in the TP53 gene?

Inactivation of the p53 protein, leading to uncontrolled cell growth Signup and view all the answers

What is the role of adenomatous polyposis coli (APC) gene in cancer?

To regulate Wnt/β-catenin signaling and prevent colon cancer Signup and view all the answers

What is the characteristic of cancer cells that allows them to invade into connective tissue?

Penetration of the basement membrane Signup and view all the answers

What is the term for the process by which cancer cells stimulate new blood vessel growth?

Angiogenesis Signup and view all the answers

What is the primary mechanism by which tumor cells evade immune recognition?

Expressing factors that suppress or 'trick' immune system Signup and view all the answers

What is the primary function of PD-L1 in tumor cells?

To inhibit immune response against tumor cells Signup and view all the answers

What is the consequence of defective DNA mismatch repair in inherited disorders?

Increased risk of colon cancer Signup and view all the answers

What is the role of BRCA1 and BRCA2 genes in cancer development?

To promote homologous recombination in DNA repair Signup and view all the answers

What is the primary consequence of genomic instability in cancer development?

Increased risk of cancer due to inability to repair DNA Signup and view all the answers

What is the primary mechanism of action of therapies targeting immune checkpoints?

Blocking PD-1 receptors on cytotoxic T cells Signup and view all the answers

What is the primary consequence of EBV and HPV evasion of immune surveillance?

All of the above Signup and view all the answers

What is the primary function of immune checkpoints in cancer development?

To inhibit immune response against tumor cells Signup and view all the answers

What is the primary function of RAS in cellular growth?

To stimulate proliferation regulators by altering genes that regulate growth Signup and view all the answers

What is the result of a mutation in the RB gene?

The checkpoint at G1-S is disabled, allowing cells to proliferate unchecked Signup and view all the answers

What is the role of ABL in signal transduction pathways?

To function as a signal transducer molecule of tyrosine kinase Signup and view all the answers

What is the primary function of MYC in cellular growth?

To activate transcription of genes that regulate growth-promoting genes Signup and view all the answers

What is the result of a mutation in the EGF receptor?

The cell becomes a constitutively active oncoprotein Signup and view all the answers

What is the role of CDK inhibitors in the cell cycle?

To enforce checkpoints to ensure defects do not move forward Signup and view all the answers

What is the primary characteristic of self-sufficiency in growth signals?

The ability to produce own growth factors or cause stromal cells to produce growth factors Signup and view all the answers

What is the result of a mutation in the HER2 gene?

The cell becomes a constitutively active oncoprotein Signup and view all the answers

What is the role of nuclear transcription factors in cellular growth?

To activate transcription of genes that regulate growth-promoting genes Signup and view all the answers

What is the result of a mutation in the signal transduction pathways involving RAS and ABL?

The cell becomes a constitutively active oncoprotein Signup and view all the answers

What is the consequence of tumor production of hormones and procoagulants?

Systemic effects and immune function alteration Signup and view all the answers

What is the cause of cachexia?

Cytokines or other soluble factors produced by the tumor and host Signup and view all the answers

What is the primary treatment for cachexia?

Remove the underlying cause (tumor) Signup and view all the answers

What is the term for symptoms not explained by local or distant spread of tumor?

Paraneoplastic syndrome Signup and view all the answers

What is the most common association of paraneoplastic syndrome?

Lung and breast cancers and hematologic malignancies Signup and view all the answers

What is the term for progressive loss of body fat and lean body mass?

Cachexia Signup and view all the answers

Which type of radiation is known to cause papillary thyroid cancer?

Therapeutic radiation to the head and neck Signup and view all the answers

What is the primary mechanism by which Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma?

By targeting CD4+ T cells Signup and view all the answers

Which of the following genes is inactivated by the E6 protein of Human Papillomavirus (HPV)?

p53 Signup and view all the answers

What is the primary mechanism by which Epstein-Barr virus (EBV) causes Burkitt lymphoma?

By stimulating proliferation of B cells through CD40 Signup and view all the answers

What is the primary mechanism by which Helicobacter pylori causes gastric adenocarcinoma and gastric lymphoma?

By stimulating chronic inflammation Signup and view all the answers

What is the primary mechanism by which Hepatitis B virus (HBV) causes hepatocellular carcinoma?

By stimulating chronic inflammation and hepatocyte death Signup and view all the answers

What is the primary mechanism by which Human T-cell leukemia virus type 1 (HTLV-1) is transmitted?

Through sexual intercourse, blood products, and breastfeeding Signup and view all the answers

Which of the following is a characteristic of Epstein-Barr virus (EBV) encoded gene, LMP1?

It promotes B-cell proliferation through CD40 Signup and view all the answers

What is the primary mechanism by which Human Papillomavirus (HPV) causes oropharyngeal carcinoma?

By inactivating p53 and RB genes Signup and view all the answers

Which of the following factors is used to determine the grade of a cancer?

Number of mitotic figures Signup and view all the answers

What does the 'T' component of the TNM system represent?

Size of the primary lesion and invasion of adjacent structures Signup and view all the answers

What is the clinical value of staging compared to grading?

Staging has greater clinical value than grading Signup and view all the answers

What does the 'N' component of the TNM system represent?

Extent of lymph node involvement Signup and view all the answers

What is the significance of 'M0' in the TNM system?

Absence of metastasis Signup and view all the answers

What is the significance of 'T0' in the TNM system?

Carcinoma in situ Signup and view all the answers

Which of the following is a characteristic of poorly differentiated cancer cells?

Loss of differentiation and a more primitive appearance Signup and view all the answers

What is the primary purpose of fine-needle aspiration in laboratory diagnosis?

To collect cells from palpable tissue masses for analysis Signup and view all the answers

What is the role of immunohistochemistry in laboratory diagnosis?

To provide a definitive diagnosis of a specific tissue type Signup and view all the answers

What is the purpose of flow cytometry in laboratory diagnosis?

To diagnose lymphomas and leukemias Signup and view all the answers

What is the role of tumor markers in laboratory diagnosis?

To screen for disease, detect recurrence, and monitor response to therapy Signup and view all the answers

What is the purpose of molecular techniques in laboratory diagnosis?

To diagnose malignancy using fluorescence in situ hybridization (FISH) or PCR analysis Signup and view all the answers

What is the role of cytologic smear in laboratory diagnosis?

To detect cervical cancer and fungal infections Signup and view all the answers

What is the role of molecular profiling in laboratory diagnosis?

To sequence entire genomes and assess modifications genome-wide Signup and view all the answers

Study Notes

Types of Neoplasms

A neoplasm is also known as a tumor, which can be benign or malignant
Depends on the host for nutrients, blood supply, and endocrine support if hormone responsive

Benign Neoplasms

Remain localized based on microscopic/gross characteristics
Can be cured of disease
Ending in "oma" (e.g., fibroma, chondroma, adenoma, papilloma)
Determined by cell type (e.g., fibroma - tumor of fibroblasts, chondroma - derived from cartilage)

Malignant Neoplasms

Locally aggressive and can spread to distant sites (metastasis)
Known as cancer
Ending in "carcinoma" or "sarcoma"
Determined by type of tissue (e.g., carcinoma - epithelial derived, sarcoma - mesenchymal derived)

Tumor Composition

Made of parenchyma (transformed/neoplastic cells) and stroma (connective tissue, inflammatory cells, blood vessels)
Parenchyma determines biologic behavior, and stroma is needed for growth

Teratoma

Type of mixed tumor containing cells from all three germ layers (ecto/meso/endoderm)
Common in ovary and testis, can be found in oral cavity (dermoid cyst)

Pleomorphic Adenoma

Most common salivary gland tumor (affects major and minor salivary glands)
Exception to benign "oma" ending

Differentiation and Anaplasia

Lack of differentiation (anaplasia) is a sign of malignancy, where cells have a backward formation
Pleomorphism is characterized by cells and nuclei of different shapes and sizes, with prominent nucleoli
Increased nuclear-cytoplasmic ratio, mitotic figures (may be atypical), and loss of polarity are indicative of anaplasia
Hyperchromatism is a characteristic of anaplastic cells, where the nucleus stains dark
Tumor giant cells are a feature of anaplasia
Dysplasia is a disturbance of architecture and proliferative disorder that increases the risk of cancer

Benign vs Malignant Neoplasm

Benign neoplasms will grow within and may be contained in a capsule, whereas malignant neoplasms will breakthrough the capsule and spread to other areas
Infiltration and destruction of underlying structures are characteristic of malignant neoplasms
Metastasis is the spread of tumor to a distant site, which can occur by blood vessels, lymphatics, or body cavities

Metastasis

Hematogenous spread usually occurs by veins (thin-walled)
The most frequent site of metastasis is the lungs
Carcinomas spread by lymphatics, while sarcomas spread by hematogenous (blood) route
Sentinel lymph node is the first node that receives lymph from the primary tumor and can be detected by injecting dye

Environmental Factors for Malignancy

Occupational exposure, sunlight (ultraviolet light), and urban location (exposure to asbestos) are environmental factors that contribute to malignancy
Important exposures include diet, smoking, alcohol consumption, and reproductive history
Infectious agents, such as viral (Human papillomavirus-HPV) and bacterial (H.pylori), can contribute to malignancy

Cancer Frequency and Death Rate

Cancer frequency increases with age
Death rate is common between 55-75 and declines after 75
Children are susceptible to cancer, including lymphomas, leukemias, CNS tumors, and sarcomas

Predisposing Conditions for Malignancy

Chronic inflammatory disorders, such as inflammatory bowel disease and Barrett esophagus, can increase the risk of malignancy
Immunodeficiency, including virus-induced malignancies, can increase the risk of malignancy
Precursor lesions, such as squamous metaplasia/dysplasia of bronchial mucosa and endometrial hyperplasia/dysplasia, are susceptible to progressing to malignancy

Genetic Abnormalities and Cancer

Genes affected by genetic abnormalities can contribute to malignant behavior of cancer cells
Oncogenes promote cell growth and encode transcription factors, while tumor suppressor genes prevent uncontrolled growth
Genes regulate apoptosis, interactions between tumor and host cells, and can be inherited or occur spontaneously
Driver mutations can activate or inactivate protein products, leading to cancer progression

Hallmarks of Cancer

Eight fundamental changes in cell physiology demonstrated by all cancers:
- Self-sufficiency in growth signals
- Insensitivity to growth-inhibitory signals
- Altered cellular metabolism
- Evasion of apoptosis
- Immortality (Limitless replicative potential)
- Sustained angiogenesis
- Invasion & Metastasis
- Evasion of immune surveillance

Self-Sufficiency in Growth Signals

Oncogenes can produce own growth factors or cause stromal cells to produce growth factors
Cell proliferation process:
- Growth factor binds to specific receptor on membrane
- Activation of growth receptor, activates signal-transducing proteins
- Transmit signal across cytosol to nucleus or by cascade of signal transduction molecules
- Activate nuclear factors that initiate & regulate DNA transcription & biosynthesis of other cellular components for cell division
- Cell enters cell cycle for cell division
Growth factor receptors:
- If mutated or overexpressed, can become oncoprotein (encoded by oncogenes)
- Examples include epidermal growth factor receptor family (EGF)-ERBB1 and ERBB2, HER2 (ERBB2) associated with breast cancers

Downstream Signal Transducing Proteins

Cancer growth can happen with mutations to signal pathways
Most common signal pathways involve RAS and ABL
RAS:
- One of the common mutated oncogenes
- Role: stimulates proliferation regulators by altering genes that regulate growth
- Bind GDP (guanosine diphosphate) and GTP (guanosine triphosphate)
- RAS is inactive with GDP, becomes activated with GTP by growth factors (EGF & PDGF)
- Becomes inactivated by losing phosphate group (reverts to GDP)
- If stays in activated state by point mutation, will continue to send pro-growth signals
ABL:
- Functions as signal transducer molecule of tyrosine kinase

Nuclear Transcription Factors

Regulate expression of growth-promoting genes
Examples include MYC gene:
- Activates transcription of genes including growth-promoting genes to drive cell cycle (especially cyclin-dependent kinases (CDK))
- If altered, keep sending cells through cell cycle and enhance changes in metabolism needed for cell growth

Cell Cycle

Four phases: Gap1-G1, Synthesis-S, Gap2-G2, and Mitosis-M
Purpose: Cells undergo DNA replication and cell division
Starts with G1 phase
Enter G1 from G0 (non-active state) or after round of mitosis
Controlled by activators and inhibitors (cyclins and cyclin-dependent kinases (CDK); checkpoints to ensure defects do not move forward (CDK inhibitors enforce checkpoints)

Checkpoints

Checkpoint 1-G1-S: monitors health of cell and DNA integrity
Checkpoint 2-G2-M: DNA is properly replicated before cell division takes place
If detect irregularities, cell can repair itself, enter senescence (can’t replicate), or apoptosis
CDK inhibitors (e.g. p16) can become defective, allow cells with damaged DNA to divide and cells at risk for malignancy

Insensitivity to Growth-Inhibitory Signals

Tumor suppressor genes:
- Slow down cell proliferation
- Cause dividing cell to enter G0 phase (quiescence)
- Can enter senescence
- Can enter apoptosis
Examples include:
- RB gene
- TP53 gene
- Other tumor suppressors: Transforming growth factor- β (TGF-β), E-cadherin, Adenomatous polyposis coli (APC) gene

RB Gene

Known as retinoblastoma gene, “governor” of the cell cycle
First tumor suppressor gene to be discovered
Regulates the G1-S checkpoint
Inactivated for cancers to occur

TP53 Gene

Known as “guardian of the genome”
Most common mutated gene in cancer
Encodes for p53 protein (transcription factor-maintains integrity of genome)
p53:
- Most important tumor suppressor
- Activated when DNA damaged and promotes DNA repair (during G1 phase)
- Role includes:
  - Place cell in quiescence
  - Induce senescence
  - Activate apoptosis
- Mutations in DNA affect dividing cells, can lead to malignant transformation if p53 lost

Altered Cellular Metabolism

Cancer cells utilize glycolytic pathway
Use high levels of glucose and glutamine and increase fermentation (glucose to lactate)
Warburg effect (aerobic glycolysis)
Glycolytic pathway used in presence of ample oxygen
Provides cancer cells with metabolic intermediates (rapidly dividing) for growth; mitochondrial oxidative phosphorylation does not

Autophagy

Tumor cells can avoid process of autophagy and survive under minimum conditions

Evasion of Cell Death (Apoptosis)

Cancer cells resistant to apoptosis by mutating genes to regulate apoptosis
Loss of p53 and overexpression of BCL-2 family prevents apoptosis

Tumor Cell Immortality & Angiogenesis

Can replicate endlessly (normal cells can replicate 70 times)
Cancer cells continue with telomere maintenance
Cells cannot enlarge beyond 1-2 mm in diameter (blood supply is needed)
Cancer cells stimulate new blood vessel growth (neoangiogenesis)
Provide nutrients, oxygen, endothelial cells help secrete growth factors to help stimulate growth of adjacent tumor cells

Tumor Cell Invasion

Cancer cells invade into connective tissue by penetrating basement membrane (basal cell layer)
Travel into connective tissue and go into vascular system by penetrating vascular basement membrane (way to metastasize to other locations)
Circulate as single cells, can form embolus by aggregating and adhering to platelets or other blood cells
Can be destroyed by host immune cells

Cancer Metastasis

For metastasis to occur, need two factors:
- Anatomic location
- Vascular drainage of primary tumor & affinity of tumor for certain tissues
Frequent sites of metastasis:
- Liver
- Lung
- Can occur in oral cavity (soft tissue and bone)

Evasion of Immune Surveillance

Immune surveillance-function of immune system to scan & destroy malignant cells
Cancer antigens-expressed by cancer cells and recognized as foreign by the immune system
Stimulate immune system and tries to prevent cancer from emerging
Tumor cells killed by cytotoxic T cells (lymphocytes) for specific antigens
Three broad categories of antigens:
- Neoantigens
- Unmutated proteins
- Viral proteins
Evasion of immune surveillance:
- Tumor cells invisible to immune system
- Tumor cells express factors that suppress or “trick” immune system
- Tumor cells change, making it difficult for cytotoxic T cells to defend properly
- Prevent immune checkpoints from working properly
Immune checkpoint:
- Main one involves PD-L1 (programmed cell death ligand 1)
- PD-L1 expressed on surface of tumor cells
- PD-1 receptor causes cytotoxic cells to be unresponsive and cannot kill tumor cells
- Therapies that target these checkpoints (especially in melanoma, lung/bladder cancer)

Genomic Instability-Enabler of Malignancy

If DNA cannot be repaired, increased risk for cancer
Inherited disorders result of defect in DNA
Examples include:
- Hereditary nonpolyposis colorectal syndrome (Lynch syndrome)
- Defect in DNA mismatch repair-cancer of cecum and proximal colon
- Xeroderma pigmentosum
- Autosomal recessive, defect in DNA repair (UV rays prevent normal replication)
- Increased risk for skin cancers (squamous cell and basal cell carcinoma)
- BRCA1 & BRCA2 genes-mutation to repair DNA by homologous recombination (develop chromosomal rearrangements and aneuploidy) susceptible to breast, ovarian, prostate cancer

Carcinogenic Agents

Three classes of carcinogenic agents: chemicals, radiant energy (radiation), and microbes
Chemicals: direct-acting agents (e.g. chemotherapy drugs), indirect-acting agents (e.g. polycyclic hydrocarbons, insecticides, arsenic, fungicides, nitrites)
Radiation: ultraviolet light from sun, radiographs, radioactive elements; therapeutic radiation to head and neck can cause papillary thyroid cancer

Etiology of Cancer

Microbes: DNA viruses (e.g. HPV, EBV, HBV), RNA viruses (e.g. HTLV-1), bacteria (e.g. H. pylori)
Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATLL), targets CD4+ T cells, and has a latency period of 40-60 years
Human Papillomavirus (HPV): low-risk types (1, 2, 4, 6, 7, 11) cause squamous papilloma and verruca vulgaris, high-risk types (16, 18, 31, 33) cause cervical, anogenital, and oropharyngeal cancer
HPV genes E6 and E7 bind and degrade p53, stimulate expression of telomerase, and inhibit CDK inhibitor p21, leading to cell proliferation and immortality

Oropharyngeal Carcinoma

Diagnosed with HPV-related cancer
Vaccines can be used to prevent HPV-related cancer (e.g. Gardasil 9, Cervarix)

Effect of E6 and E7 Proteins

Inactivate RB, p53, and p21, leading to cell proliferation and immortality

Epstein-Barr Virus

Can cause infectious mononucleosis, oral hairy leukoplakia, Burkitt lymphoma, nasopharyngeal carcinoma, and Hodgkin lymphoma
Virus attaches to CD21 receptor, infects B cells, and promotes B-cell proliferation through latent membrane protein 1 (LMP1)

Nasopharyngeal Carcinoma

LMP1 expressed through NF- K B pathway
Genetic and/or environmental factors contribute to development

Burkitt Lymphoma

LMP1 acts as an oncogene, promoting B-cell proliferation through normal B-cell activation pathway
Genetic and/or environmental factors contribute to development

Hepatitis B

Causes hepatocellular carcinoma (liver cancer) through chronic inflammation, hepatocyte death, and NF- K B pathway activation

Helicobacter pylori

Causes gastric adenocarcinoma and gastric lymphoma through chronic inflammation
Classified as a carcinogen
Can stimulate B-cell proliferation and promote inflammatory cytokines

Clinical Aspects of Neoplasia

Effect on host: injury from benign/malignant tumors, damage to healthy tissues, release of hormones and procoagulants, and alteration of immune function
Cachexia: progressive loss of body fat and lean body mass, profound weakness, anorexia, and anemia, caused by cytokines or other soluble factors produced by tumor and host

Paraneoplastic Syndrome

Symptoms not explained by local or distant spread of tumor
May represent earliest manifestation of occult neoplasm
Can produce clinical illness and be lethal
May mimic metastatic disease, commonly associated with lung, breast, and hematologic malignancies

Grading and Staging of Cancer

Grading is based on the differentiation of tumor cells, number of mitotic figures, tumor necrosis, and presence of architectural features.
Can be described as well, moderate, or poorly differentiated, or as low or high grade.

TNM Staging System

T: Size of primary lesion and invasion of adjacent structures (T1-T4, T0: carcinoma in situ).
N: Extent and spread to lymph nodes/involvement (N1-N3, N0: no nodal involvement).
M: Presence or absence of metastasis (M0: no metastasis, M1: presence of metastasis).
Staging has greater clinical value than grade and determines the type of treatment.

Laboratory Diagnosis

Frozen Section

Performed during surgery, using fresh tissue.
Evaluates margins, metastasis, and nodal involvement.
Can be accurate but other methods are used to arrive at a final diagnosis.

Fine-needle Aspiration

Collection of cells from a palpable tissue mass analyzed within minutes.
Used to evaluate lymph nodes, thyroid gland, breast, and parotid.

Cytologic Smear

Used to detect cervical cancer, fungal and viral infections (e.g., candidiasis, herpes).
Superficial cells are collected and analyzed for abnormalities.

Excisional/Incisional Biopsy

Used for lesions that are greater than 1 cm or suspected malignancy.
A small piece is removed for definitive diagnosis.

Immunohistochemistry

Used with routine H&E to accurately diagnose a specific tissue type.
Helps with tumors that are poorly differentiated (e.g., cytokeratin markers to diagnose carcinoma).

Flow Cytometry

Helps diagnose lymphomas and leukemias.

Tumor Markers

Can be used as a screening tool, detect recurrence of disease, and response to therapy.
Utilize a blood sample (e.g., prostate specific antigen (PSA) for prostate cancer).

Molecular Techniques

Diagnose malignancy using fluorescence in situ hybridization (FISH) or PCR analysis.
Detect minimal residual disease, help with prognosis and behavior, and determine type of therapy to use.
Detect hereditary risk for cancer and provide genetic counseling.

Molecular Profiling

Involves the analysis of individual genes or entire genome.
Helps with identifying recurrent mutations in different cancers, patient care, and treatment.
Measures all RNA expressed in cell population, proteins, and metabolites.

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Description

This quiz covers the basics of oncology, including the characteristics of benign and malignant tumors, their growth patterns, and differences between the two.