Mediastinal diffuse large-cell lymphoma with sclerosis. A clinicopathologic study of 60 cases.

A retrospective analysis was conducted of 60 cases of mediastinal diffuse large-cell lymphoma with sclerosis (MDLLS). The study group consisted of 43 females and 17 males. Eighty-five percent were 35 years of age or younger at time of initial diagnosis. Thirty are alive and well at least 1 year after diagnosis (median: 34.5 months), six are alive with disease (median: 13 months), 20 died of disseminated disease (median: 16.5 months), and four died of other causes. Complete autopsy was performed on eight of the patients who died of disease. The most frequently involved extrathoracic organs were lymph nodes, kidney, liver, pancreas, gastrointestinal tract, and ovary. Fifty-six cases were classified according to the Lukes-Collins scheme: 35 were follicular center cell, 13 immunoblastic T (IBT), seven immunoblastic B (IBB), one a composite of IBB and nodular sclerosing Hodgkin's disease; four cases were unclassifiable. Lymphoreticular origin was proven immunohistochemically in 53 cases, including the four unclassifiable examples and eight cases typed as B-cell tumors. Unfavorable prognostic factors were age less than 25 years at diagnosis, tumor outside the thoracic cavity at presentation, disease recurrence, and IBT or IBB tumor histology. Favorable signs were good response to initial therapy and marked tumor sclerosis. MDLLS is most often mistaken for malignant thymoma, seminoma, and Hodgkin's disease. Criteria helpful for the recognition of MDLLS are discussed.