Neoplasia — Flashcards

Flashcard 551: Medulloblastoma is a form of primitive _____ tumor (embryonic tissue origin)

Answer: neuroectodermal

Extra: Medulloblastoma T2-weighted cranial MRI (axial view) of a 7-year-old boy: isodense round lesion with hyperintense sections in the fourth ventricle (green overlay); grossly diminished gyration of the cerebellum (C). (P = poorly demarcated pons region; B = basilar artery, CS = external CSF space) Medulloblastoma T1-weighed cranial MRI of a 6-year-old child presenting with features of increased intracranial pressure (midsagittal section with contrast) There is a large hypointense mass occupying the third (upper yellow overlay) and fourth (lower yellow overlay) ventricles that is causing obstructive hydrocephalus (pink overlay). The pink overlay also highlights the leakage of CSF into the periventricular space (transependymal edema) and into the occipital lobe due to the increased intraventricular pressure. This appearance of a fourth ventricular mass in a child is characteristic of medulloblastoma. Medulloblastoma Cranial MRI (T1-weighted, with contrast) There is a mass in the posterior cranial fossa. It features solid parts (green overlay) and cystic parts (red overlay). Location and appearance are typical of a medulloblastoma. (D: diencephalon; P: pons; C: cerebellum; yellow outline: cerebellar tentorium) Medulloblastoma Photomicrograph of cerebellar vermis tissue (H&E stain) Densely packed, small, blue anaplastic cells are present throughout the specimen. The cells have pleomorphic and hyperchromatic nuclei. On the right, a vessel (its lumen mostly obstructed by eosinophilic material) can be seen. These are typical histopathological findings of medulloblastoma. Medulloblastoma Photomicrograph of cerebellar vermis tissue (H&E stain) Numerous small, blue, round cells with scant cytoplasm can be seen throughout the specimen (classic examples: arrows, green overlay). Their nuclei vary in size and structure (nuclear pleomorphism) and many cells feature distinctly hyperchromatic nuclei. The majority of the cells are arranged in concentric clusters around lighter central areas consisting of neuropil (examples: dashed outlines and yellow overlay, magnified area). These clusters are referred to as Homer Wright rosettes. These histopathological features, particularly the Homer Wright rosettes, are characteristic of a medulloblastoma. Atlas:

Flashcard 552: _____ differentiated tumors closely resemble their tissue of origin, whereas _____ differentiated tumors look almost nothing like tissue of origin

Answer: Well

Flashcard 553: Ovarian tumors may arise from three different cell types: 1. _____ 2. _____ (e.g. oocyte) 3. _____ (e.g. granulosa & theca cells)

Answer: surface epithelium

Flashcard 554: What benign bone tumor affects men and women equally (most common in adolescents)? _____

Answer: Enchondromas

Flashcard 555: Dysplasia is a term used only with _____ cells

Answer: epithelial

Flashcard 556: Chronic myeloid leukemia is characterized by increased levels of mature _____

Answer: granulocytes (eosinophils, neutrophils, basophils)

Flashcard 557: What is the prognosis of the mucinous carcinoma subtype of invasive ductal carcinoma (breast)? _____

Answer: Good

Extra: * Happy dogie

Flashcard 558: Chronic lymphocytic leukemia commonly involves lymph nodes, leading to generalized lymphadenopathy; thus called _____ lymphoma

Answer: small lymphocytic

Extra: Other:

Flashcard 559: Some _____ secrete PTH-related peptide (PTH-rp), which is structurally homologous with the PTH secreted by the parathyroid glands

Answer: malignant tumors

Flashcard 560: What is the most common malignant hepatic lesion? _____

Answer: Liver metastasis

Extra: * most commonly from the colon and lungs