Question of the Day

This is a basal cell tumor. Basal cells make up the base of the epidermis, and a benign growth of these is called a basal cell tumor or adenoma. Although this tumor is benign, surgical removal is the treatment of choice due to ulceration and secondary inflammation. Basal cell carcinomas (the malignant form) do not form raised masses but appear as ulcers on the head, neck, and legs: surgical removal is also recommended.

Basal cell tumors are common in older cats, accounting for 15-26% of all feline skin tumors. Most are slow growing and typically present for months prior to diagnosis. Domestic longhairs, Himalayans, and Persians are predisposed.

Note the characteristic cytology findings of epithelial neoplasia present in this case: cohesive clusters of large, round to polygonal cells, demonstrating distinctive cell borders, that are tightly adherent to each other with round to oval nuclei.

Image courtesy of Dr. Seth Chapman.