FAMILIAL MELANOMA IN THE PROGENY OF A DUROC AND SLOVAK WHITE CROSSBRED SOW

In three successive litters of a Duroc and Slovak White crossbred sow there was a 7.75% overall incidence of melanoma. Immunohistochemical l abelling confirmed the mesenchymal origin of the neoplastic cells, ind icated the absence of CD3 lymphocytes in the tumour, and proved the tu morous origin of surrounding non-pigmented cells. An abundance of macr ophages (epithelioid cells) with increased endoplasmic reticulum was o bserved by electron microscopy, but large granular lymphocyte-like cel ls were few in number. (C) 1995 Academic Press Limited