Amelanotic malignant melanoma in a Himalayan Rex guinea pig (Cavia porcellus).

Allnoch, Lisa; Köstlinger, Saskia; Steffensen, Nicole; Hewicker-Trautwein, Marion; Lehmbecker, Annika

doi:10.1016/j.jcpa.2020.09.010

published

Amelanotic malignant melanoma in a Himalayan Rex guinea pig (Cavia porcellus).

Allnoch, Lisa ; Köstlinger, Saskia ; Steffensen, Nicole ; Hewicker-Trautwein, Marion ; Lehmbecker, Annika

A Himalayan Rex guinea pig was presented with a history of nodular, partially ulcerated masses in the subcutis of the left shoulder. Histological examination revealed a garland-like to nodular, infiltrative neoplastic mass of the epidermis and hair follicle epithelium, which obscured the dermoepidermal junction. Neoplastic cells were immunopositive for S100, PNL-2, vimentin and melan-A antigens. No immunolabelling of CD3, CD79, Iba-1 or pancytokeratin was observed. This is the first detailed description of spontaneous amelanotic malignant melanoma in this species.