Cutaneous melanoma - Atlas of swine pathology
Where: skin and subcutaneous tissue
Possible causes: Other
Slaughtered pig that shows protruding areas on its left side with black-coloured spaces inside them. At a microscopic level, groups of cells with a brownish-black pigment that become discoloured when hydrogen peroxide is applied are seen. It is a cutaneous melanoma.
Tumours in pigs are rare, because of their age of slaughter.
We should make a differential diagnosis with lesions such as abscesses (with a thick green-yellowish content) or granulomas (caseous content, frequently calcified). When cut, the tumours are normally solid, although they can sometimes show liquefied areas due to necroses.