Toby Schmitt, MD

Couldn't be more excited to announce the launch of pathlibrary.com, the virtual slide site I wish had existed during my pathology residency. You can: - Order special stains to work up cases - See annotated histologic features - Prepare for exams with board-style questions

Intramuscular myxoma: - Small spindle cells (black arrow) in a pale, bluish myxoid stroma - Entrapped skeletal muscle fibers (blue arrow) See the entire slide and more annotated features: pathlibrary.com/slidebox/?case…

Aggressive angiomyxoma: - "Aggressively thick-walled" blood vessels - Small, bland spindle cells in a myxoid background - Extravasated red blood cells common WSI and more info: pathlibrary.com/slidebox/?case…

60F with a polypoid uterine lesion. What's going on with the spindled stroma? Order stains and see the whole slide image at: pathlibrary.com/slidebox/?case…

Olfactory neuroblastoma: - Nests of small round blue cells with salt and pepper chromatin. - May have Homer-Wright rosettes, or arrangements of tumor cells around neuropil (blue box). See more annotated features at: pathlibrary.com/slidebox/?case…

Hemangioblastoma: - Sheets of epithelioid cells packed with vacuoles. - Like other VHL-associated tumors, cells have clear cytoplasm and background capillaries are abundant. WSI and more info: pathlibrary.com/slidebox/?case…

BAP1-inactivated melanocytoma: - Large epithelioid melanocytes with distinct cytoplasmic borders - Symmetrical and tends to show maturation with depth - Loss of nuclear BAP1 staining Whole slide image and more info at: pathlibrary.com/slidebox/?case…

Lymphoepithelioma-like carcinoma: - Syncytial aggregates of large epithelioid cells surrounded and infiltrated by a dense lymphoid infiltrate - Often associated with EBV, but not in the skin (cutaneous lesions are EBER-ISH negative). WSI: pathlibrary.com/slidebox/?case…

Canalicular adenoma: Cords and elongated tubules formed by monomorphic columnar cells. WSI: pathlibrary.com/slidebox/?case…

PathLibrary is expanding - check out 200 new cases, with a focus on blood films and neuropathology.

Basal cell adenoma of the salivary gland: - Has a thick basement membrane around and within nests of basaloid cells - Resembles cylindroma of the skin WSI: pathlibrary.com/slidebox/?case…

An unusual sessile serrated lesion with dysplasia (SSLD). The area of dysplasia resembles a traditional serrated adenoma with columnar cells showing abundant eosinophilic cytoplasm. WSI and more info: pathlibrary.com/slidebox/?case…

Verruciform xanthoma: V-shaped eosinophilic areas in the epithelium/epidermis point down, telling you to look for the foamy histiocytes below. WSI link: pathlibrary.com/slidebox/?case…

Sclerosing stromal tumor: - Branching, staghorn vessels - Lobules containing vacuolated epithelioid cells separated by sclerotic stroma WSI: pathlibrary.com/slidebox/?case…

Polymorphous adenocarcinoma: Architectural complexity, cytologic uniformity. WSI: pathlibrary.com/slidebox/?case…

Secretory carcinoma of the breast: - Cyst formation with PAS+ eosinophilic luminal secretions - Hyalinized fibrous bands - Triple negative (ER-, PR-, HER2-) - Pan-TRK IHC + due to ETV6::NTRK3 fusion (t(12;15)) 🔬WSI: pathlibrary.com/slidebox/?case…

Glomeruloid forms in the prostate: - Pathognomonic of prostatic adenocarcinoma - Considered a type of Gleason pattern 4 WSI: pathlibrary.com/slidebox/?case…

PathLibrary is now officially mobile-friendly! Go through virtual teaching slides anytime, anywhere.

Gingival lesion, < 1 yo F. Order stains, view the whole slide image, and see the diagnosis at: pathlibrary.com/slidebox/?case…

Uterine mass, 60F. Order stains, view the whole slide image, and see the diagnosis at: pathlibrary.com/slidebox/?case…