Immunohistochemical evaluation of a malignant pheochromocytoma in a wolfdog

A malignant pheochromocytoma with multiple metastases was diagnosed in a 7- year-old male wolfdog that resulted from a cross between an eastern timber wolf (Canis lupus lycaon) and an Alaskan malamute. A yellowish white neopla stic mass approximately 10 cm diameter was found in the right adrenal gland . The neoplasm penetrated through the wall of the caudal vena cava. A diagn osis of pheochromocytoma was established by histopathologic and immunohisto chemical procedures. Immunohistochemically, the neoplastic cells expressed chromogranin A, substance P, synaptophysin, Leu-7, protein gene product 9.5 , methionine-enkephalin, S100 protein, and galanin. Multiple metastatic tum ors were found in the kidneys, spleen, lungs, heart, and liver.