Primary splenic presentation of malignant lymphoma and related disorders. A study of 49 cases.

The diagnosis of malignant lymphoma presenting as an initial splenic manifestation may go unrecognized as such when peripheral lymph nodes are not enlarged and when results of bone marrow biopsies are negative. Tissues from 49 patients, ranging in age from 15 to 78 years, in whom the original diagnosis of malignant lymphoma and related conditions was made at splenectomy, were classified as: diffuse small lymphocytic (20), diffuse large cell (11), diffuse small cleaved (5), diffuse large cell, immunoblastic (5), follicular small cleaved cell (3), and follicular mixed small cell and large cell (2). Two additional spleens, diagnosed as acute blastic leukemia, were initially confused with malignant non-Hodgkin's lymphoma by light microscopy. One patient presented with Hodgkin's disease confined to the spleen. For the non-Hodgkin's lymphoma group, parameters of age, sex, splenic weight (range, 226-4000 g), lymph node, bone marrow, or liver involvement did not adversely influence prognosis. Abdominal lymph nodes were positive in 31 of 37 patients having splenic hilar and/or abdominal lymph nodes available for review. Of 29 patients with adequate follow-up, 7 died of disease, 5 were free of disease at 3 years, 2 were free of disease at 5 years, 2 were alive with disease at 3 years, 4 were alive with disease at 5 years, and 9 died from second malignancies, unknown, or unrelated causes. Six of the 7 patients who died of lymphoma were classified as large cell (four diffuse large cell and two diffuse large cell, immunoblastic), with a mean 2-year survival. One patient died of leukemia. Those lymphomas classified as low grade behaved in an indolent fashion. The morphologic diversity of these cases emphasizes the need for the initial recognition and correct classification of lymphomas which present in the spleen, since survival is best determined according to histologic type.