Abstract
A 31-year-old male spotted seal (Phoca largha) was examined at necropsy. Multiple masses were observed in systemic organs, including the lung, stomach, pancreas, greater omentum, and pulmonary lymph nodes. Histologically, pulmonary masses contained numerous solid nests composed of polygonal tumor cells and often central keratinization, whereas those were less keratinization in the stomach, which tumor emboli were observed in the vessels. On immunohistochemistry, tumor cells were positive for keratin 5, pancytokeratin AE1/AE3, and p63 but negative for vimentin, cytokeratin CAM5.2, and calretinin. Based on macroscopical, histological, and immunohistochemical features, this case was diagnosed as squamous cell carcinoma with systemic metastases. The primary site in this case was probably the lung, with vascular metastases to distant organs including the stomach, omentum, and pulmonary lymph nodes. To the authors' knowledge, this is the first description of squamous cell carcinoma in a spotted seal.
