Occurrence of monocytoid B-cells in reactive lymph node lesions.
Benign monocytoid B-cells are a peculiar subset of B-cells. They are closely related to marginal zone B-lymphocytes, show cytological diversity and may be recognized in a variety of reactive lymph node conditions. To analyze the incidence, cytological spectrum and phenotypic features of benign monocytoid B-cells, we investigated a series of 301 consecutively biopsied and unselected cases of reactive lymph node change from 1988 and 1995. A monocytoid B-cell reaction was identified in 46 (15%) cases and could be cytologically subclassified into two groups: 31 (67%) cases with common-type cells and 15 (33%) cases with large, transformed cells, according to the description by Plank et al. [19]. These reactions were regularly associated with follicular hyperplasia (95%) and were part of an epithelioid cell response in 24 cases (50%). Immunohistologically, both types of benign monocytoid B-cells were negative for bcl-2 protein expression, which was in contrast to the bcl-2 positive reaction in marginal zone B-lymphocytes and their neoplastic counterpart in monocytoid B-cell lymphoma. An association of Epstein-Barr virus (EBV) with monocytoid B-cells was investigated by in situ-hybridization. EBV genomes were detected in five (15%) of 31 cases tested. In each of these five cases, positive cells were represented in both high and low numbers. The morphologic features of the EBV-positive cells were not consistent with monocytoid B-cells, but rather with medium-sized to large lymphoid cells. It appeared that the occurrence of monocytoid B-cell reaction in reactive lymph node lesions was not related to EBV infection in the majority of cases.
Department of Pathology, Ashikaga Red Cross Hospital, Japan.
M
M
Kojima
S
S
Nakamura
H
H
Itoh
K
K
Yoshida
K
K
Shimizu
T
T
Motoori
N
N
Yamane
T
T
Joshita
T
T
Suchi
D000293:Adolescent; D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D048429:Cell Size; D004854:Herpesvirus 4, Human / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008199:Lymphadenitis / Q000209:etiology / Q000276:immunology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology / Q000473:pathology*; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D012367:RNA, Viral / Q000032:analysis
D011518:Proto-Oncogene Proteins; D012367:RNA, Viral