#PathSky

Epithelioid GIST can be tricky!

#PathSky #LiverPath

Anastomosing hemangioma (kidney): Lobulated architecture with anastomosing, sinusoidal, capillary-sized vessels lined by hobnail endothelial cells with rare mitotic activity and no endothelial multilayering. Despite their complex appearance, they behave in a benign manner. PMID 19606014. #PathSky

Intramucosal adenocarcinoma in Barrett. Architectural complexity, nuclear atypia with large nucleoli, and poorly formed glands. p53 shows null staining pattern, suggestive of biallelic inactivation of TP53, leading to complete loss of expression. #PathSky #GIPath

Interval appendicitis: Crohn-like features (fissuring ulcers, granulomas, transmural lymphoid aggregates), xanthogranulomatous inflammation, fibrosis, giant cells, features mimicking mucinous neoplasm (extravasated mucin, goblet cell hyperplasia, etc). #PathSky

#GIpath #SkyPath

Epithelioid GIST can be tricky, especially when metastatic, as it can present variable histomorphology (neuroendocrine-like, plasmacytoid, atypia, etc.) and aberrant staining patterns (e.g. keratin). This is a liver biopsy. #PathSky #GIpath