Cervical lymph node metastases of tonsillar squamous cell carcinoma in a Shih-tzu

Abstract

A 8-year-old female Shih-tzu dog (weighting 4.5 kg) with history of both hindlimb lameness and cervical mass was presented to Veterinary Teaching Hospital, Gyeongsang National University. In physical examination, ataxia, kyphosis, back pain and cervical mass were identified. Marked periosteal new bone formation of the fourth lumbar vertebra and soft tissue opacity mass of cervical region were observed in survey radiographs. Transverse computed tomography (CT) scan obtained at the lumbar and cervical lesions shown a well defined multilobulated bony mass and partially destructive lytic lesions the fourth lumbar vertebral body and a enlarged retropharyngeal lymph node with heterogeneous contrast enhancement and moderately enhancing left tonsillar mass. Neoplastic squamous epithelium which have developed vessel and lymphocyte infiltration in surrounding tissue were confirmed based on histopathologic examination. Based on the diagnostic findings the dog was diagnosed as a cervical lymph node metastases of tonsillar squamous cell carcinoma.