Cutaneous Leiomyoma in a Goldfish Carassius auratus

Abstract

This study describes the histopathological features of a cutaneous leiomyoma in a goldfish. A mass, measuring 3.5 × 2 × 1 cm, located dorsolaterally along the cranial lateral line above the right operculum. The mass was sessile and golden orange with hemorrhagic foci. Histological examination revealed interlacing bundles of spindled to elongated tumor cells with cigar-shaped nuclei with no malignancy. The tumor cells showed red color with Masson’s trichrome stain. Immunohistochemically, the tumor cells were positive for vimentin, desmin and α-smooth muscle actin, but not for S100. Based on these findings, this case was diagnosed as a cutaneous leiomyoma.