How to differentiate between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease.  Evidence for the value of MB1 and 4KB5 immunostaining. 
Striking morphological similarities exist between T-cell-rich B-cell lymphoma and lymphocyte-predominant Hodgkin's disease (Hodgkin's paragranuloma), making the distinction between them extremely difficult.  Immunohistochemistry provides a means of overcoming this difficulty.  Immunostaining with UCHL1, L26, MB1, and 4KB5 was performed on five T-cell-rich B-cell lymphomas and 11 Hodgkin's paragranulomas (7/11 nodular, 4/11 diffuse).  L26 stained the tumour cells not only of T-cell-rich B-cell lymphomas, but also of L+H Hodgkin's disease.  In contrast, MB1 as well as 4KB5 identified all of the neoplastic cells in 3/5 T-cell-rich B-cell lymphomas, but did not react with the L+H cells in 8/11 Hodgkin's paragranulomas.  Some overlap of staining patterns became apparent in the remaining cases, with 2/5 T-cell-rich B-cell lymphomas showing the MB1+/4KB5+ phenotype in a tumor cell subset only.  Similarly, in 3/11 Hodgkin's paragranulomas, some MB1/4KB5-positive L+H cells occurred in addition to MB1/4KB5-negative L+H cells.  These cases, nevertheless, could be distinguished from one another by the numbers of MB1/4KB5-positive background lymphocytes, which were scanty or absent in T-cell-rich B-cell lymphomas and more numerous in Hodgkin's paragranulomas.