title: Histiocyte-rich B-cell lymphoma. A distinct clinicopathologic entity possibly related to lymphocyte predominant Hodgkin's disease, paragranuloma subtype.
abstract: This study reports six non-Hodgkin's lymphoma cases that we called histiocyte-rich B-cell lymphoma (BCL) because of the prominent reactive histiocytic infiltrate obscuring the malignant B-cell population. The involved lymph nodes are characterized by a mixed nodular and diffuse infiltrate and occasionally feature prominent sinuses. The infiltrate is composed of reactive lymphocytes and numerous histiocytes obscuring a tumor population composed of variably sized scattered cells with irregular or multilobar vesicular nuclei. Immunostaining of paraffin sections for the B-cell marker recognized by L26 helps in the identification of these neoplastic cells. The clonal nature and further evidence of the B-cell lineage of this condition is shown by immunoglobulin gene rearrangements detected in three cases. The six cases of histiocyte-rich BCL are remarkably similar clinically: all presented with stage IVB disease with splenomegaly and follow an aggressive clinical course. Except for these features, our series show striking similarities to paragranuloma lymphocyte-predominant Hodgkin's disease, including male preponderance (all patients are male), age distribution (mean age, 41 years), propensity to progress to a diffuse, large B-cell lymphoma (two cases), as well as morphology of the neoplastic B-cell population and expression of Hodgkin's cell markers (Leu-M1 positivity after neuraminidase digestion in three cases, Leu-M1 positivity without neuraminidase digestion in one case, and additional epithelial membrane antigen [EMA] positivity in two cases). Both morphologically and clinically, the present series can be differentiated from other types of infiltrate-rich BCL, such as T-cell-rich BCL. Although additional cases will have to be recognized, histiocyte-rich B-cell lymphoma most likely represents a distinct clinicopathological entity. We speculate that it develops from a subset of B cells that also gives rise to the lymphocytic-histiocytic (L/H) cell, the Hodgkin's cell variant of lymphocyte-predominant Hodgkin's disease, paragranuloma subtype.
authors.affiliation: Department of Pathology II, University Hospitals, Leuven, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Delabie
authors.forename: E
authors.initials: E
authors.lastname: Vandenberghe
authors.forename: C
authors.initials: C
authors.lastname: Kennes
authors.forename: G
authors.initials: G
authors.lastname: Verhoef
authors.forename: M P
authors.initials: MP
authors.lastname: Foschini
authors.forename: M
authors.initials: M
authors.lastname: Stul
authors.forename: J J
authors.initials: JJ
authors.lastname: Cassiman
authors.forename: C
authors.initials: C
authors.lastname: De Wolf-Peeters
mesh_terms: D000328:Adult; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000235:genetics; D005838:Genotype; D006689:Hodgkin Disease / Q000175:diagnosis / Q000473:pathology*; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics; D007150:Immunohistochemistry; D008099:Liver / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D018396:Mucin-1; D013154:Spleen / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm; D007136:Immunoglobulins; D008562:Membrane Glycoproteins; D018396:Mucin-1