ABSTRACT
Pilomatricomas are cystic hair follicle neoplasms originate from matrix cells which is produced by hair shaft and Inner root sheaths of this zone region of the inferior part of the hair follicle there is cornification patterns are present. These structures are recognized almost exclusively in dogs. A five-year-old, male intact boxer dog was presented with a large pedunculated mass in medial aspect of elbow region. The histopathological findings were confirmed by immunohistochemistry. The tumor was BCC like with lobules of tumor basal cells and shadow cell-like necrotic cells showing central keratinization. Immunohistochemically, the CK7was negative that revealed this tumor could not to be a BCC. Positivity for CK8 revealed that this tumor originated from hair sheath. Nonentity of invasion and metastasis and negativity for P53 iniplicated that the turn or was benign. This tumor was proliferative pigmented pilomathcoma because of a large number of basal cells of lobules and melanophages in the interlobular fibrous tissue. This report can be useful in oncoming reclassification of canine skin tumors