QUESTION 86
A researcher is working with gliomas in an attempt to understand the pathogenesis. One of her projects involves studying a mutated isocitrate dehydrogenase gene. Of the following, by which mechanism does this mutated gene promote neoplasia?
A. Production of 2-hydroxyglutarate
B. Production of a telomerase
C. Promotion of release of E2F
D. Over-production of bcl-2
E. Under-production of bcl-2
Answer for Question 86
Answer: A (production of 2-hydroxyglutarate)
Explanation: mutated isocitrate dehydrogenase genes result in the production of an enzyme that catalyzes the formation of 2-hydroxyglutarate, which inhibits the TET2 family of of enzymes, leading to altered DNA methylation, which causes abnormal expression of genes. Mutated RB gene can result in abnormal release of E2F and promotion of the cell cycle. Over-production of bcl-2 would inhibit apoptosis by stabilizing the mitochondrial membrane, and under-production of bcl-2 could indirectly promote apoptosis and death of the neoplastic cells.
QUESTION 87
A medical student is on a 4th year pathology elective and is sitting at the microscope with their attending physician looking at a biopsy of a cervix. The pathologist points out areas of dysplasia to the medical student. The finding of which of the following features would indicate carcinoma was present within the areas of dysplasia?
A. Markedly increased number of mitotic figures
B. Increase in nuclear:cytoplasm ratio
C. Separate nests of squamous cells resembling the dysplastic cells, but in the dermis
D. Prominent new blood vessel formation
E. Dysplastic cells extending from the basement membrane to the apical surface
Answer for Question 87
Answer: C (Separate nests of squamous cells resembling the dysplastic cells, but in the dermis)
Explanation: A, B, and E are found in areas of dysplasia, with the presence of these features increasing as dysplasia progresses from low grade to high grade. Separate nests of squamous cells resembling the dysplastic cells, but in the dermis would imply invasion, which is a feature of carcinoma. While angiogenesis is a component of neoplasia, the presence of angiogenesis alone would not allow for the diagnosis of neoplasia.
QUESTION 88
A pathologist is examining a prostate biopsy. Focally, within the biopsy is a small cluster of tissue characterized as small glands that are back-to-back, as opposed to the normal prostatic glandular tissue that is characterized by large glands with intervening space. The pathologist determines that the focus of cells is neoplastic. Of the following, what would be the best name for this focus of neoplastic cells?
A. Squamous cell carcinoma
B. Adenocarcinoma
C. Adenosarcoma
D. Leiomyosarcoma
E. Teratoma
Answer for Question 88
Answer: B (adenocarcinoma)
Explanation: as the pathologist is looking at neoplastic glands, the neoplasm is a carcinoma (and not sarcoma, teratoma, lymphoma, or melanoma). As the neoplasm is derived from glands, the appropriate term is adenocarcinoma. Squamous cell carcinoma of the prostate would be rare, but could derive from squamous metaplasia, but the cells of origin are squamous cells.