Abstract
A 7-year-old female Pointer dog with multiple masses in the axilla, mammary gland, and bladder was submitted to the Pathology Department of the College of Veterinary Medicine in the Jeju National University. Grossly, mass between right axilla and 1st mammary gland, $15{\times}10cm$ in size, was well delineated and firm, slightly soft center, oval shape. And masses in right 1st, 3rd and 5th mammary gland were well delineated and sulphur yellow in color on the cut-surface. Numerous round to oval shaped masses, 0.3 to 2 cm in diameter were existed in the lung. Urinary bladder mucosa had rough and thick and round to oval papillary masses, 0.1 to 2 cm in diameter, on surface. Microscopically, masses in right axilla, 1st mammary gland, lung and axillary lymph node were composed of poorly differentiated tubules originated from apocrine gland. Lining neoplastic epithelium showed high mitotic figures, typical apical secretory blebs, and PAS-positive diastase-resistant cytoplasmic granules. Masses in 3rd and 5th mammary gland were confirmed as mammary complex adenoma and simple adenoma respectively. The masses in the urinary bladder were covered with stratified transitional epithelium with marked cellular atypia and high mitotic figures. Some neoplastic cells showed focal invasion into substantia propria of bladder. Immunohistochemaically, neoplastic transitional epithelium demonstrated positive reactions for cytokeratin 7, AE1/AE3, and MNF116. Based on the gross, histopathologic and immunohistochemical characteristics, this dog was diagnosed as apocrine carcinoma, mammary gland tumor including simple adenoma and complex adenoma and bladder transitional cell carcinoma. And distant metastases of apocrine carcinoma in right axilla were observed in axillary lymph node and lungs. This is the first report for concurrent occurrence of apocrine carcinoma, mammary gland tumor, and transitional cell carcinoma in a same dog.