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Littoral cell angioma
Splenic vascular lesion, Factor 8 and lysozyme positive, high endothelium
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inflammatory fibroid polyp
benign myofibroblastic lesion, well circum, cd34, bcl2 and ckit positive. stomach small bowel, myxoid, eos and inflammatory cells. ddx IMT
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malakoplakia in kidney
resembles xanthogranulomatous pyelonephritis, interstitial infiltration by foamy histiocytes, michaelis gutmann bodies PAS positive, central calcification on EM
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granular cell tumor
classic location tongue, oral cavity, PAS positive cytoplasm granules that are lysosomes on EM.S100 positive, calretinin positive, , favor schwann cell origin, overlying pseduoepith hyperplasia
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pleomorphic adenoma/benign mixed tumor
most common salivary tumor, parotid, typical is biphasic with epithelial and stromal components. usually glandular epith, myoepithelial and fibromyxoid stroma.
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Nipple duct adenoma
florid papilloma/tosis of the nipple duct, benign, polypoid shape, continuity with the overlying skin. epith, myoepith cells, lack of atypia, steaming, etc.
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pheochromocytoma
association with vHL, Carney triad (GIST, pulm chondroma, extra adrenal pheo), s100 positive sustentacular cells, EM shows small, uniform, dense-core granules. Malignancy 10%
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wilms tumor
- 11p13 mutation WT-1 zinc finger trsc factor and WT-2.
- Prognostic facotrs: most important is anaplasia defined as: marked nuclear enlargement of any cell line 3 times size, hyperchromasia, multipolar mitotic figures.
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papillary thyroid carcinoma follicular variant
PTC- most common sporatic mutation, RET protoconcogene, tk activity. Follicular variant nuclear featres most important - clear cells with overlapping nuclei. behavoir is analagous to regular PTC
Follicular carcinoma, different mutation PAX8-PPAR and high ras mutations, more vascular invasive, not lymph node like PTC
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insular thyroid carcinoma
tumor that falls in between well diff PTC and FC and anaplastic carcinoma. Old folks, grossly invasive, often mistaken for MTC. Nesting insular pattern, solid to microfollicular pattern, small uniform cells. TTF-1 thyroglobulin bcl2 positive, negative for calcitonin. focal positivity for NE markers.
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hepatic adenoma vs fnh vs hcc
very rare, women, associated strongly with oral contraceptive use, can lead to rupture and fatal hemoperitoneum. Lack portal triads and central veins. No central scar, although can have central hemorrhage. Trabeculae are 1-3 cells thick, no atypia, no nucleoli. FNH should have central scar and have all biliary architectural compoenents. also aberrant central vessel. HCC has thickened trabeculae (often 4+) with more cytologic atypia. Reticulin,l pCEA, Hepar1, AFP. Well diff HCC can have thinner trabeculae.
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