A follow-up study of 537 cases of Hodgkin's disease, lymphocyte predominance type, nodular--designated as nodular paragranuloma (NP)--found simultaneous presence of (n = 11) or subsequent transition into (n = 3) a large cell lymphoma (LCL) in 14 cases. Morphologically, the LCLs were classified in ten cases as centroblastic lymphoma (malignant lymphoma, diffuse, large cell, non-cleaved cell), in three cases as immunoblastic lymphoma (malignant lymphoma, large cell, immunoblastic), and in one case as large cell anaplastic lymphoma. Eleven of the 14 LCLs were studied immunohistologically. Five cases showed a monotypic immunoglobulin (Ig) pattern, seven were positive to the monoclonal B-cell marker Ki-B3, and three showed both monotypic Ig and Ki-B3 positivity. With anti-Ig and Ki-B3, nine of the 11 LCLs could be classified as B-cell non-Hodgkin's lymphoma. Only one case of LCL exhibited the typical phenotype of Hodgkin cells, ie, positivity to anti-CD15 (3C4) and anti-CD30 (Ber-H2). A retrospective follow-up study of these secondary LCLs of B type revealed a longer survival time than that of primary B-type LCLs and other secondary LCLs. These findings indicate that B-type LCL is the most common outcome when NP progresses into a lesion of higher malignancy and provide further evidence of a close relationship of NP to the B-cell system. They also suggest that it would be clinically relevant to distinguish between cases of B-type LCLs secondary to NP and cases of LCLs without association with NP. This implies that signs of a preexisting NP should be looked for when a B-type LCL is diagnosed.