Oncopathology & Histopathology Answers

### 1. Differentiate between benign and malignant tumours. **Benign tumours:** - Well differentiated - Encapsulated and well circumscribed - Do not invade locally or metastasize - Remain at primary site - Slow growth rate - Amenable to surgical removal **Malignant tumours:** - Most are anaplastic; variable differentiation - Non-encapsulated - Locally invasive, cause tissue damage - Ability to metastasize from primary site - Rapid growth rate - Surgical intervention less effective ### 2. Define differentiation, anaplasia, pleomorphism, and dysplasia. - **Differentiation:** How similar tumour parenchymal cells are to normal parenchymal cells in morphology and function - **Anaplasia:** Lack of cellular differentiation - **Pleomorphism:** Differences in cell appearance (shape, size, features) - **Dysplasia:** Disorderly cellular growth ### 3. Give two examples each of: **a) Carcinomas:** - Adenocarcinomas - Squamous cell carcinomas **b) Sarcomas:** - Fibrosarcomas - Osteosarcomas ### 4. Define choristoma and hamartoma. - **Choristoma:** Group of cells found in locations where they are not normally found (ectopic cells) - **Hamartoma:** Group of cells clumped together in an unusual way ### 5. List the hallmarks of cancer. - Self-sufficiency in growth signals - Insensitivity to growth inhibitory signals - Limitless replicative potential - Evasion of apoptosis - Altered cellular metabolism - Sustained angiogenesis - Ability to invade and metastasize - Evasion of the immune system - Genomic instability - Tumour-enabling inflammation ### 6. Name five oncogenic viruses and the cancers they cause. - **Epstein-Barr Virus (EBV)** - Burkitt Lymphoma, Nasopharyngeal carcinoma - **Human T-cell Leukemia Virus (HTLV)** - Adult T-cell Leukemia - **Hepatitis B Virus** - Hepatocellular carcinoma - **Human Papilloma Virus (HPV)** - Cervical cell carcinoma, Anal carcinoma - **Human Herpes Virus 8/Kaposi Sarcoma-associated Herpes Virus** - Kaposi Sarcoma ### 7. Define tumour markers. Substances whose presence indicates the presence of a neoplasm in the body. They can be enzymes produced in elevated amounts, proteins only produced in embryogenesis, or ectopic hormones from tumours. ### 8. Give examples of tumour markers and the conditions they indicate. - **Alpha-fetoprotein (AFP)** - Liver, yolk sac tumours - **Carcinoembryonic Antigen (CEA)** - Various carcinomas - **CA-125** - Ovarian cancer - **CA 19-9** - Pancreatic cancer - **CA 15-3** - Breast cancer ### 9. State the uses of tumour markers. - Diagnosis of malignancy - Prognosis of malignancy - Detection of minimal residual disease - Determination of therapy - Investigation of drug resistance ### 10. Define cytopathology. The study of the effect of diseases on individual cells morphologically. Includes the changes cells go through as a result of disease. ### 11. Define histopathology. A branch of pathology that deals with the study of the effects of diseases on individual tissues. ### 12. What is a laboratory request form? An official form of communication between a clinician and laboratory staff. Contains details on the procedures requested by the clinician for the laboratory staff to perform. ### 13. Define tissue fixation. A histological method of preservation of tissue specimens that includes physical and chemical methods that stop vital cellular processes while maintaining tissue shape and volume for further histologic/cytologic examination. ### 14. Define tissue decalcification. The process of removal of minerals from calcified tissues to allow preparation of thin tissue sections for examinations. ### 15. Define fine needle aspiration (FNA). A method of sample collection in which a superfine needle is used to collect cells from the body. These cells are aspirated and placed on a slide for examination. ### 16. Define aspiration cytology. A minimally invasive procedure in which study of cells is obtained by invading body organs minimally and collecting specific cells which are taken out and further examined. ### 17. Define exfoliative cytology. Study of cells obtained from skin and mucous membranes. Could be obtained by brushing or washing of membranes. ### 18. Define immunohistochemistry. The use of specific antibodies to identify and illustrate antigens. An immunologic reaction whereby antibodies specific to certain antigens are used to show their presence in tissues. ### 19. What are frozen sections? Tissue samples prepared using a cryostat to cut and freeze them for the purpose of rapid diagnosis. Can be done during an operation. ### 20. List the components of a laboratory request form. **Patient's information:** - Full name of patient, age, gender, requesting clinician's name **Specimen information:** - Type of procedure requested (e.g., biopsy) - Location of specimen (e.g., laparoscopy left breast) **Clinical information:** - Should be clearly written by clinician - Should include previous reports on any procedure perf