Squamous cell carcinoma of unknown primary in a dog presented with bone metastasis

Abstract

A 10-year-old American Pit Bull dog was diagnosed with a metastatic undifferentiated carcinoma in scapula. Immunohistochemistry was positive for cytokeratins (AE1/AE3, 34BE12, CK7) and Vimentine confirming a squamous cell carcinoma. After a complete physical examination and imaging techniques no evidence of nodules were identified. A carcinoma of unknown primary was diagnosed. Amputation and adjuvant chemotherapy using doxorubicin and piroxicam were performed and after 737 days of diagnosis, patient died because of respiratory failure. Necropsy confirmed undifferentiated carcinoma infiltrating lungs and kidneys, showing same immunoexpression than tumor in scapula. Amputation associated with chemotherapy extended the overall survival time in this case.