Lymphomatoid granulomatosis-like lesions in malignant lymphoma.

Eighty five cases of malignant lymphoma were surveyed for the presence of angioinfiltrative and angiodestructive growth pattern of lymphoid cells with areas of necrosis and granulomatous appearance simulating lymphomatoid granulomatosis (LYG). LYG-like changes were observed in 13 of 85 cases (15%). The most frequent histology was diffuse large cell lymphoma which occurred in 8 cases (4 non-cleaved, 3 cleaved, and one immunoblastic), followed by three diffuse pleomorphic lymphoma, one diffuse medium-sized lymphoma, and one Hodgkin's disease of mixed cellularity. The most frequent involving site was the lung, as well as the soft tissue. Composition of lymphoid infiltrate varied markedly from case to case and from area to area in the same case. One was solely composed of monotonous atypical cells, other pleomorphic cells including benign lymphocytes, plasma cells, leukocytes, and histiocytes with a varied number of atypical reticuloendothelial cells. The latter histologic appearance was just similar to LYG. Veins were more frequently affected than arteries. The present study indicates that, although the angioinfiltrative and angiodestructive growth pattern of atypical lymphoreticular cells with granulomatous appearance is considered necessary for the diagnosis of LYG, it often occurs in malignant lymphoma. Therefore, one should consider the possibility of malignant lymphoma before making the diagnosis of LYG, especially in the specimens taken from the lung and soft tissue.