THE PATHOLOGY OF CUTANEOUS LEISHMANIASIS DUE TO LEISHMANIA-MAJOR IN SUDAN

The pathology of cutaneous leishmaniasis in Sudan, where the disease i s caused by Leishmania major, was studied by light and electron micros copy. Lesions were classified into four distinct groups based on the r atio of different cell types, especially lymphocytes, macrophages, and plasma cells in the inflammatory infiltrate. and the formation of com pact epithelioid granulomas or the presence of necrosis. In the lesion s, there was a positive correlation between the number of lymphocytes and the number of activated macrophages and epithelioid cells. We sugg est that the parasites are eliminated from the lesion by two processes : 1) a lytic mechanism in which parasites are lysed within activated m acrophages and 2) necrosis of parasitized macrophages. Morphologic evi dence for these two mechanisms of parasite elimination was detected by both light and electron microscopy. The evolution of the pathology of the lesions was followed by rebiopsy when the lesion had regressed in size under antileishmanial therapy.