Dysplasia and Tumor Overview

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Questions and Answers

What is a characteristic feature of dysplasia?

Reduced mitotic activity

Disordered maturation and loss of normal arrangement (correct)

Increased normal tissue uniformity

Consistent cell size and shape

Which grade of dysplasia indicates changes restricted to the lower third of the surface epithelium?

Grade IV

Grade I (correct)

Grade II

Grade III

What causes dysplasia according to the content?

Acute trauma

Chronic inflammation or irritation (correct)

Genetic mutations only

Normal aging process

What is the ultimate progression of Grade III dysplasia?

Progresses to carcinoma in situ Signup and view all the answers

What defines a tumor (neoplasia) in the content?

Unlimited and uncontrolled growth Signup and view all the answers

What is the main characteristic of benign tumors compared to malignant tumors?

They are usually capsulated and remain localized. Signup and view all the answers

Which term refers to a malignant tumor arising in mesenchymal tissue?

Sarcoma Signup and view all the answers

Which type of benign tumor is classified based on a gland pattern?

Adenoma Signup and view all the answers

What defines locally malignant tumors?

They infiltrate locally but do not send distant metastases. Signup and view all the answers

Which of the following is NOT a characteristic of malignant tumors?

They are usually well-defined and capsulated. Signup and view all the answers

Which of the following suffixes indicates a benign tumor?

-oma Signup and view all the answers

What determines the rate of growth in malignant tumors?

Level of differentiation Signup and view all the answers

What is the prefix for a benign tumor arising in cartilage?

Chondro- Signup and view all the answers

What is a key feature that differentiates malignant tumors from benign tumors?

They can spread to distant sites in the body. Signup and view all the answers

Which method of distant spread is typically favored by carcinomas?

Lymphatic spread Signup and view all the answers

Which of the following tumors is classified as a benign tumor?

Giant cell tumor of bone Signup and view all the answers

What is the first step in the local spread (invasion) process of a malignant tumor?

Detachment of tumor cells from each other Signup and view all the answers

Which statement about hematogenous spread is true?

Arteries may be eroded during hematogenous spread. Signup and view all the answers

What is one potential effect of local tumor invasion?

Severe hemorrhage if a blood vessel is invaded Signup and view all the answers

What does the presence of tumor cells away from the primary tumor mass indicate?

Distant spread (metastasis) Signup and view all the answers

Which type of tumor is least likely to metastasize through the lymphatic system?

Sarcoma Signup and view all the answers

What is the process by which tumor cells pass through blood vessel walls to reach the bloodstream?

Intravasation Signup and view all the answers

How do tumor emboli avoid detection by the immune system during metastasis?

By adhering to leukocytes and platelets Signup and view all the answers

Which of the following describes the final process of tumor cells forming metastases in new sites?

Homing Signup and view all the answers

Which organ is most commonly associated with metastasis from tumors drained by systemic veins?

Lungs Signup and view all the answers

What is organ tropism in the context of metastatic tumors?

The specific preference of certain tumors for particular organs Signup and view all the answers

Which of these is a rare site for metastases?

Pancreas Signup and view all the answers

What can influence where tumor cells migrate to in the body?

Anatomical vascular distribution and adhesion molecules Signup and view all the answers

Which of the following scenarios illustrates a unique pathway for cancer spread?

Cancer kidney metastasis to the left testis Signup and view all the answers

What is the primary characteristic of metastatic deposits in gross examination?

Scattered round nodules Signup and view all the answers

How do tumor cells primarily spread through the lymphatic system?

By lymphatic embolism and permeation Signup and view all the answers

Which of the following describes lymphatic permeation?

Malignant cells multiply inside the lymphatic without node involvement Signup and view all the answers

What gross appearance is associated with affected lymph nodes during lymphatic spread?

Enlarged, firm, and grayish Signup and view all the answers

What is 'skip metastasis' as it relates to lymphatic spread?

Metastatic cells traveling from one lymph node to a distant node Signup and view all the answers

What can lead to reactive hyperplasia in lymph nodes affected by carcinoma?

Stimulation by tumor antigen Signup and view all the answers

What effect does transcoelomic spread have on organs covered by serous membranes?

Mechanical implantation on the organ surface Signup and view all the answers

Which of the following describes areas visible in metastatic deposits?

Areas of hemorrhage and necrosis Signup and view all the answers

Study Notes

Dysplasia

Disordered cellular proliferation, not neoplastic
Loss of cell uniformity and normal tissue arrangement
Often accompanies metaplasia or hyperplasia
Sites: skin, mucus membranes, liver
Difficult to detect by gross examination
Microscopic appearance:
- Hyperchromasia: increased nuclear staining
- Pleomorphism: variation in size and shape
- Mitotic activity
- Loss of normal orientation (polarity) and disordered maturation
Causes: chronic inflammation, irritation, chronic infection
Grades:
- Grade I: restricted to lower third of surface epithelium
- Grade II: involves middle third
- Grade III: involves nearly whole thickness
Prognosis:
- Grade I and II dysplasia can be reversible
- Grade III progresses to carcinoma in situ (whole thickness dysplasia but basement membrane intact, no invasion) and finally invasive carcinoma

Tumor (Neoplasia)

Abnormal mass of tissue
Growth exceeds normal tissue, progressive, unlimited, autonomous, uncontrolled by normal growth controls
Composed of:
- Parenchymal component (neoplastic cells) - determines tumor name
- Supporting non-neoplastic stroma

Classification of Tumors

According to cell of origin:
- Epithelial
- Mesenchymal
- Miscellaneous
According to behavior:
- Benign
- Malignant
- Locally malignant

Characteristics of Benign and Malignant Neoplasms

Differentiation and Anaplasia:
- Differentiation: the extent to which the parenchymal cells resemble their normal counterparts
Rate of Growth:
- Benign: grows slowly, affected by blood supply, hormones, location
- Malignant: grows faster, correlates with level of differentiation
Local Invasion:
- Benign: remains localized, cannot invade, usually capsulated
- Malignant: progressive invasion, destruction, usually not capsulated

Nomenclature

Benign Tumors:
- Prefix + Suffix
- Type of cell + (-oma)
- Examples:
  - Fibroma: benign tumor of fibrous tissue
  - Lipoma: benign tumor of fatty tissue
  - Chondroma: benign tumor of cartilage
  - Leiomyoma: benign tumor of smooth muscle
  - Rhabdomyoma: benign tumor of skeletal muscle
Epithelial Benign Tumors: Classified based on:
- Cell of origin
- Microscopic pattern
- Macroscopic pattern
Adenoma: benign epithelial neoplasms producing gland pattern
Papilloma: benign epithelial neoplasms growing on any surface that produce finger-like patterns

Malignant Tumors

Malignant Tumor of Mesenchymal Tissue: SARCOMA
- Fibrosarcoma (from fibrous tissue)
- Osteosarcoma (from bone)
- Chondrosarcoma (from cartilage)
Malignant Tumor of Epithelial Origin: CARCINOMA
- Squamous cell carcinoma
- Renal cell adenocarcinoma
- Cholangiocarcinoma

Other Malignant Tumors

Melanoma (skin)
Mesothelioma (mesothelium)
Seminoma (testis)
Lymphoma (lymphoid tissue)

Locally Malignant Tumors

Infiltrate locally but do not metastasize
Slower rate of growth than malignant tumors
Mode of growth: infiltration
Microscopically malignant cells
May turn malignant, recur after incomplete removal
Examples:
- Basal cell carcinoma of skin
- Giant cell tumor of bone (osteoclastoma)
- Adamantinoma of the mandible
- Craniopharyngioma
- Gliomas (tumors of neuroglial cells)
- Carcinoid tumor

Spread of Malignant Tumors

Local Spread ("invasion"): Presence of tumor cells away from their origin without loss of continuity
Distant Spread (metastasis): Presence of tumor cells away from the primary tumor mass without continuity; main cause of death

Local Spread (Invasion)

Invasion of the extracellular matrix (basement membrane and interstitial connective tissue) following the least resistance
Four steps:
1. Detachment of tumor cells from each other
2. Attachment of tumor cells to the surrounding tissue (through receptors)
3. Degradation of the extracellular matrix
4. Migration of tumor cells through the degraded extracellular matrix
Effects:
- Adhesion to surrounding structures
- Functional insufficiency
- Severe hemorrhage when invading a blood vessel
- Pain when invading a nerve
- Obstruction of hollow organs
- Ulcer
- Fistula

Distant Spread (Metastasis)

Presence of tumor cells away from the primary tumor mass without continuity.
Main difference between benign and malignant tumors
Methods:
1. Lymphatic spread: favored by carcinomas
2. Blood (hematogenous) spread: favored by sarcomas, veins commonly invaded
3. Transcoelomic spread: through serous sacs
4. Implantation
5. Inoculation

Hematogenous (Blood) Spread

Most common pathway of distant spread in sarcoma than carcinoma
Some carcinomas have early tendency for hematogenous spread:
- Follicular thyroid carcinoma
- Hepatocellular carcinoma
- Renal cell carcinoma
- Prostatic carcinoma
- Choriocarcinoma
- Lung small cell carcinoma
- Breast carcinoma
Veins are more susceptible to penetration than arteries
Arteries may be eroded causing fatal hemorrhage

Mechanism of Hematogenous Spread

Intravasation: Tumor cells invade the extracellular matrix and blood vessel wall to reach the blood
Embolization: Malignant cells pass with blood stream as tumor emboli by adhering to leukocytes and platelets, hidden from the immune system
Extravasation: Tumor emboli are impacted in a narrow blood vessel, invade its basement membrane and pass outside the vessel
Homing: Tumor cells proliferate at the new site to form metastatic deposits

Sites of Vascular Metastasis

Emboli derived from systemic veins enter the right side of the heart and travel to the lungs, causing lung metastasis
Exceptions:
- Tumor cells bypass lung through ventricular or atrial septal defect to the systemic circulation
- Tumor cells are small enough to pass through lung capillaries
- Metastasis of pelvic, abdominal, or thoracic tumors through the paravertebral system of veins to the brain and spinal cord
- Metastasis of cancer of the kidney to the left testis through the left testicular vein
Emboli derived from tumors of the lung are carried by the pulmonary vein to the left side of the heart and systemic arterial circulation
Emboli from organs drained by the portal blood travel to the liver

Homing of Tumor Cells

Common sites: liver, lung, brain, bones, and adrenals
Certain tumors prefer certain sites (organ tropism):
- Prostatic carcinoma to bone
- Bronchial carcinoma to adrenals and brain
- Neuroblastoma to liver and bone
Organ tropism may be related to:
- Anatomical vascular distribution
- Expression of adhesion molecules
- Chemo-attractants
Rare sites: muscle, spleen, pancreas, intestine

Pathology of Metastatic Deposits

Grossly:
- Scattered round nodules of variable sizes, related to vascular distribution
- Hard consistency
- Grayish-white color
- May have hemorrhage and necrosis
Microscopically:
- Metastatic deposits resemble the primary tumor

Lymphatic Spread

Lymphatic vessels lack a basement membrane, facilitating invasion
Major pathway of distant spread of carcinoma
Methods:
- Lymphatic embolism: aggregates of tumor cells pass with lymphatic vessels to the draining lymph node
- Lymphatic permeation: malignant cells multiply inside the lumen of lymphatic vessels, causing obstruction and edema
Causes of lymph node enlargement draining the region affected by carcinoma:
1. Reactive hyperplasia with sinus histiocytosis
2. Secondary infection
3. Lymphatic spread

Spread Through Body Cavities (Transcoelomic Spread)

Occurs through serous cavities from organs covered by serous membranes
Mechanism: malignant cells detach and implant on the surface of another organ
Effects: multiple secondaries

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Description

Explore the concepts of dysplasia and neoplasia, including characteristics, grades of dysplasia, and their implications for prognosis. Understand the implications of cellular abnormalities and the progression to carcinoma. This quiz will test your knowledge on these important topics in pathology.