fibrosarcoma in a goldfish (carassius auratus): a case report

Neoplasms in fishes are generally less aggressive than neoplasms in mammals and are most commonly discrete and focal. although tumors were originated from connective tissue are frequently seen in the fishes, but dermal fibrosarcoma is rarely found in fish. a moribund four years old goldfish (carassius auratus), was referred veterinary hospital of shahid chamran university of ahvaz with an exophytic nonulcerated mass near the caudal peduncle. microscopic examination of the mass revealed proliferated spindle cells and the interlacing, loose and eosinophilic bundles. for differential diagnosis, masson’s trichrome staining was performed and the fibers stained blue. according to histopathological and histochemical results, tumor identified as fibrosarcoma. it is the first report of histopathological features of cutaneous fibrosarcomas in a goldfish in iran.