Fibromyxoma in a flower horn fish (hybrid cichlid)

A 3-year-old male flower horn fish with a mass on the head protuberance was referred to the Ornamental Fish Clinic, Faculty of Veterinary Medicine, University of Tehran. On gross examination, the mass was approximately 4 × 15 × 25 mm in size. The fish was anesthetized in 100 ppm PI222 (Pars Imen Daru, Iran). The mass was removed surgically and the wound repair was monitored postoperatively in the Ornamental Fish Clinic for 40 days. Tissue samples of the mass were fixed in 10% neutral buffered formalin, sectioned and stained with haematoxylin and eosin, periodic acid-schiff, and Masson׳s trichrome. Microscopically, as a consequence of the concomitant presence of collagenous areas infiltrating myxoid areas, the neoplasm was classified as a fibromyxoma.