Pathological characteristics of oral lymphomas.

Nine cases of oral extranodal lymphomas are described. Histologically, 6 cases were histiocytic, 2 lymphocytic and 1 Burkitt's lymphoma. According to the criteria of the Japanese Lymphoma Study Group, 8 cases seemingly belonged to the B-cell lymphoma classification, and one was unclassified. Geographical differences in the distribution of oral extranodal lymphomas between Japan and western countries were surveyed. A review of our cases and those in the literature revealed no significant difference in sex, age, frequency of B-cell lymphomas or site of predilection. In Japan, histiocytic lymphomas were the most common type of extranodal oral lymphomas. The most prevalent type of oral extranodal lymphomas in western countries could not be determined from the literature.