Generalized nodular dermatofibrosis and renal cystadenocarcinomas in a German shepherd dog

Generalized, nodular dermatofibrosis with coexisting bilateral renal cystadenocarcinomas was diagnosed in a 6-year-old male German Shepherd Dog. Approximately 3 years earlier, the dog had been examined because of lameness attributable to 2 nodular growths between the third and fourth digits of the right front limb. Biopsy revealed dense collagenous dermal fibrosis, often in a nodular arrangement. As the disease progressed, attempts to alleviate the discomfort and lameness caused by the nodular growths were performed by surgical excision. During this period, other nodular growths that developed apparently did not bother the dog. Because of the long and protracted clinical progression of the disease and poor prognosis for successful treatment, the dog was euthanatized. At necropsy, multiple multicentric nodules were found in the skin and subcutis, with most located on the limbs. The nodules were well-circumscribed and hard. Epithelial ulceration and inflammation were confined to nodules on the feet. Small foci of collagenous proliferation were found along fascial planes. In addition, cystic neoplasms were in both kidneys. The microscopic diagnosis was generalized nodular dermatofibrosis, with bilateral renal cystadenocarcinomas.