Dermal chondrosarcoma in a cat with prolonged survival after limb amputation

Abstract

A 5‐year‐old male entire domestic shorthair cat presented with a firm dermal mass on the dorsal left metatarsal region. Diagnostic investigations included haematology, biochemistry, urinalysis, biopsy, histopathology and computed tomography staging. Histopathology of the tissue biopsy, including immunohistochemistry, confirmed a dermal chondrosarcoma (CSA), and computed tomography supported an extraskeletal origin. Pretreatment staging did not identify metastatic disease. Curative‐intent limb amputation was therefore performed, resulting in tumour‐free surgical margins. No adjuvant treatment was used. The cat underwent regular reevaluation for 3 years and remained free of local recurrence or metastatic disease. Dermal CSA is rarely reported in cats, and information regarding biological behaviour and outcome is limited. This patient experienced long‐term control, demonstrating that with complete surgical excision alone, extraskeletal CSAs can have a favourable outcome.