Occurrence of monocytoid B-lymphocytes in Hodgkin's disease.

The nature and frequency of occurrence of monocytoid B-lymphocytes (MBL) was examined in 118 cases of Hodgkin's disease. Monocytoid cells were present in six cases (5%), four nodular sclerosis and two mixed cellularity. These cells were CD20+, CD3-, CD45RO-, KP-1-, PGM1-, with occasional positive reaction for MB-1 and CD74, indicating their B-cell nature, i.e., MBL. The MBL were distributed in the periphery of the nodules of nodular sclerosis accompanying centrally located Reed-Sternberg cells, although Reed-Sternberg cells were observed in some MBL clusters. In the mixed cellularity, MBL were located in the para-follicular area occasionally adjoining the lymph follicles. Because previous studies suggested depressed immune function in autoimmune diseases, acquired immune deficiency syndrome, and older persons to be responsible for the occurrence of MBL, it is possible that in some patients development of foci of MBL under immunodeficient conditions progresses to Hodgkin's disease.