Couldn't be more excited to announce the launch of 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

Do you have interesting scanned slides you'd like to share?. You can now upload your own digital slides to (up to 15 GB). There's also the option to add the results of special stains/molecular testing as well as annotated histologic features.

Celiac disease:.- Brunner glands confirm this biopsy is from the duodenum. - However, the surface resembles colonic mucosa, indicating villous blunting. - Increased intraepithelial lymphocytes are seen. Ddx: Infection, drug, Crohn's. WSI, more info:.

Trichilemmoma:.- Appears as a bulbous epidermal proliferation that is clearer/whiter than the surrounding epidermis.- Peripheral palisading, reverse polarity (blue box) are common. See more annotated features at:.

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:.

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:

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:

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:

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:

Canalicular adenoma: Cords and elongated tubules formed by monomorphic columnar cells. WSI:

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:

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:

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

Sclerosing stromal tumor:.- Branching, staghorn vessels.- Lobules containing vacuolated epithelioid cells separated by sclerotic stroma. WSI:

Polymorphous adenocarcinoma: Architectural complexity, cytologic uniformity. WSI:

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:

Aggressive angiomyxoma:.- "Aggressively thick-walled" blood vessels.- Small, bland spindle cells in a myxoid background.- Extravasated red blood cells common. WSI and more info:

Glomeruloid forms in the prostate:.- Pathognomonic of prostatic adenocarcinoma.- Considered a type of Gleason pattern 4. WSI:

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