A non-cutaneous form of melanoma in a goat during meat inspection: case report

Document Type: Case Study


1 Islamic azad university, Tabriz branch, Tabriz, Iran

2 Islamic azad university, Babol branch, Babol, Iran


Malignant melanoma is a neoplasm that originates from melanocytes. This tumor is seen in cutaneous and non-cutaneous forms and it is considered as one of the most dangerous types of cancers. Non-cutaneous melanoma is a complex of unique and malignant complications that are easily separable from cutaneous type. Since UV radiation from the sun damages DNA and is an oxidative stress factor in melanoma and also there are more melanocytes in the basal layer of skin than other parts of the body, the cutaneous form has more prevalence. Most of the time non-cutaneous form is the result of cutaneous metastasis but both forms can occur primarily. Non-cutaneous forms usually happen in, mucosal layers, intestines and eyes and the main reason of it is ectopic melanocytes or unwanted regressive growing of them. Malignant melanoma can occur in all domestic animals however, they seem to be rare in sheep and goats. Herein, we describe a rare case of the primary non-cutaneous form of malignant melanoma, in a three-year-old indigenous female goat. In meat inspection procedures at Tabriz slaughterhouse, we encountered numerous round firm black masses on visceral surfaces and serous membranes of the abdominal and thoracic cavities. The Liver and lungs were prominently affected. Samples were taken from involved parts and malignant melanoma was confirmed in the histopathologic examination due to pleomorphism and polymorphism and melanin pigments in cells with eosinophilic cytoplasm. Due to what was written in “manual on meat inspection for developing countries” book, the carcass was not convenient for human use and condemned by the inspector.