Malignant Mixed Tumor of Salivary Gland in a Dog

Abstract

A tumor was observed in the left mandible of a 3-year-old male Shih-Tzu dog. Histopathology revealed neoplastic alveolar proliferation of round cells, sarcomatoid proliferation of round to spindle-shaped cells and an existing parotid gland tissue around the tumor. A cancellous bone framework was also seen throughout the tumor. The tumor cells in the sarcomatoid area were positive and weakly positive for vimentin and cytokeratin, respectively, demonstrating their myoepithelial character. We diagnosed this tumor as a malignant mixed tumor of the salivary glands, because of the location of the tumor, its invasiveness into the surrounding tissue and the identification of both epithelial and myoepithelial tumor cells.

Unilateral mixed adenoma of the third eyelid lacrimal gland in a boxer dog

“… 20 , 21 Clinical outcome data for these salivary tumors are primarily limited to single case reports. 22 , 23 , 24 , 25 Mixed adenomas and carcinomas of apocrine sweat glands in dogs are similarly uncommon with clinical outcome data limited to single case reports. 26 , 27 , 28 , 29 , 30 …”

“…20,21 Clinical outcome data for these salivary tumors are primarily limited to single case reports. [22][23][24][25] Mixed adenomas and carcinomas of apocrine sweat glands in dogs are similarly uncommon with clinical outcome data limited to single case reports. [26][27][28][29][30] Given the nature of this case, no follow-up information is available, and a necropsy was declined so neither regional nor distant metastasis can be ruled out.…”

“…Salivary gland neoplasms in domestic species are rare, and both pleomorphic adenomas (benign mixed tumors) and malignant mixed tumors of the salivary gland are reported 20,21 . Clinical outcome data for these salivary tumors are primarily limited to single case reports 22–25 . Mixed adenomas and carcinomas of apocrine sweat glands in dogs are similarly uncommon with clinical outcome data limited to single case reports 26–30 …”