Cryptococcus in AIDS patient. The yeast forms of C. Neoformans are intermediate in size (5-15 um), much larger than Histoplasma capsulatum (2-4 um) and much smaller than the spherules of C. Immitus (20-200 um with 2-4um endospores). Blastomyces dermatitidis and Paracoccidiiodes immitus are similar in size but non-encapsulated. C. neoformans infections usually involve the CNS secondarily after primary lung infection in AIDS patients.
NS Hodgkin = Lacunar cells. Node is effaced in a pattern of nodules carved out by bands of sclerosis. Classic RS ARE present, but the distinctive cell type is the LACUNAR CELL (large cell with a round to convoluted vesicular nucles and variably sized nucleolus). The lacunar look is from formalin, not seen in B5. Mummified cells are also present. Background of mature lymphs, PC, and eos. Histiocytes/granulomas are seen. NS is most common type of HL in western world, affects YOUNG FEMALES and…
melanoma The aspirates show markedly atypical cells in a single cell pattern. The cells are large with abundant cytoplasm and macronucleoli. Binucleated forms and cytoplasmic tails are also noted. Close inspection of the cytoplasm of some of the tumor cells reveals faint pigmentation (Image 4, center cell and lower right).
Mesothelioma. The presence of intercellular windows and cytoplasmic skirts are two important diagnostic clues in this case. Both features support mesothelial origin and both are the result of long floppy microvilli that characterize mesothelial cells. Other less specific cytologic features that support mesothelial origin include: Single cell population scalloped borders of fragments papillary architechture cell-in-cell arrangements multinucleation
The smears show cohesive groups of epithelioid cells that have abundant vacuolated cytoplasm, fairly distinct cell borders, moderate nuclear pleomorphism, round nuclei, and prominent nucleoli. The core biopsies show a neoplasm with delicate vasculature and epithelial cells with clear cytoplasm.