Multiple Cutaneous Tumors including Merkel Cell Carcinoma in a Cat

Here we describe the clinical and pathological findings of a 15-year-old cat with multiple cutaneous tumors including Merkel cell carcinoma. The cat was presented with a cutaneous mass in the lumbar region which was histopathologically diagnosed as Merkel cell carcinoma with lymph node metastasis. Multifocal cutaneous lesions were also observed in the dorsal region. They were histopathologically diagnosed as Bowenoid in situ carcinoma, basal cell carcinoma, and cutaneous mast cell tumor. The cat died 154 days after initial presentation, and autopsy revealed metastatic lesions of Merkel cell carcinoma in the pelvic cavity. This report describes the detailed autopsy and histopathological findings of a feline Merkel cell carcinoma accompanied by various other cutaneous tumors.