Chromatophoromas on the tail of a pet axolotl (Ambystoma mexicanum) with presumptive metastasis

Abstract

Background

Reported neoplasia in amphibians is rare with axolotls (Ambystoma mexicanum) and African clawed frogs (Xenopus laevis) being overrepresented. Reported neoplasia in axolotls include chromatophoromas, teratomas, and neuroblastomas.

Case Description

A 3-year-old intact female axolotl was presented with a pigmented bilobed right proximal tail mass and a vascular left proximal tail mass. The patient was anesthetized with alfaxalone via immersion bath and subcutaneous injection, and the tail was amputated proximal to the masses. The axolotl recovered uneventfully and was discharged with oral medications. Histopathology of the tail masses revealed incomplete excision of presumptive iridophoromas (a subset of chromatophoroma). Complete tail regeneration occurred after 7 months with no gross reoccurrence of the masses. The patient presented 9 months post-operatively with a 3-week history of decreased appetite. Coelomic ultrasound revealed a vascularized coelomic mass caudal to the liver. Euthanasia was performed and necropsy revealed presumptive metastasis of the chromatophoromas into the spleen and kidneys.

Conclusions and case relevance

Chromatophoromas with potential for metastasis should be considered in axolotls with cutaneous masses.