Oncogenes and proto-oncogenes — Flashcards

Flashcard 1: The Knudson two-hit hypothesis states that _____ copy/copies of a tumor suppressor gene must be knocked out for tumor formation

Answer: both

Flashcard 2: Tumor _____ defines the degree of cellular differentiation and mitotic activity

Answer: grading

Flashcard 3: Mutations in which proto-oncogene can lead to Colon Cancer, Non-Small Cell Lung Adenocarcinoma, and Pancreatic Cancer?_____

Answer: KRAS

Flashcard 4: Which oncogene is associated with Neuroblastoma?_____

Answer: N-myc overexpression

Flashcard 5: What is the mechanism that results in malignancy from the L-MYC oncogene?_____

Answer: amplification

Flashcard 6: What is the associated tumor that results from point mutation of the KIT oncogene?_____

Answer: Gastrointestinal stromal tumor (GIST)

Flashcard 7: Ovarian tumor associated with a pulling sensation in the groin and histology showing bundles of spindle-shaped fibroblasts?

Answer: Ovarian Fibroma

Extra: • Clinical: Pulling sensation in groin. • Histology: Bundles of spindle-shaped fibroblasts. • Association: Meigs syndrome (Ovarian fibroma, Ascites, Hydrothorax).

Flashcard 8: What is the characteristic histological finding and cell type in a Brenner tumor?

Answer: "Coffee bean" nuclei; contains Walthard cell rests (transitional epithelium)

Extra: Brenner tumor: - Mostly benign ovarian surface epithelial tumor. - Histology: Characterized by "coffee bean" nuclei (longitudinal nuclear grooves) and nests of transitional epithelium (resembling bladder mucosa) called Walthard cell rests. - Gross: Solid, tan-white/yellow, well-encapsulated.

Flashcard 9: Is mucinous cystadenocarcinoma benign or malignant?

Answer: Malignant

Extra: Mucinous cystadenocarcinoma is the malignant counterpart of mucinous cystadenoma. It is a common primary surface epithelial tumor of the ovary, characterized by multiloculated cysts lined by atypically proliferated mucinous epithelium showing stromal invasion.

Flashcard 10: Morphological features of Mucinous Cystadenoma?

Answer: Multilocular cyst lined by mucus-secreting epithelium (Benign)

Extra: Mucinous cystadenomas are most commonly found in the ovary or pancreas. Characterized by large, multiloculated cysts filled with gelatinous fluid. Unlike serous cystadenomas, these are less likely to be bilateral in the ovary.