Diagnosable without a microscope:

Attending during signout: "So did you look at all the slides?"

- Accumulation of aluminum chloride (Drysol), a hemostatic agent, in a skin biopsy - Histiocyte cytoplasm gets a chunky, slightly granular appearance; can be confused with granular cell tumor - PAS+, S100-

Lung, GMS stain:

A baby porokeratosis:

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

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

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

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…

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

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…

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

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

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…