title: Intrasinusoidal bone marrow infiltration: a common growth pattern for different lymphoma subtypes.
abstract: We report a retrospective immunohistochemical study on bone marrow biopsies of 43 patients with different types of lymphomas showing unusual intrasinusoidal infiltration. Most of these patients presented with splenomegaly (74.4%) and peripheral lymphocytosis (83%). In 20/43 patients, lymphoid infiltrates were not detectable on haematoxylin-eosin sections. After immunohistochemistry on bone marrow biopsies and blood and bone marrow smear examinations, the following diagnoses were made: splenic marginal zone lymphoma with villous lymphocytes (SLVL) in 24 patients, large granular lymphocyte (LGL) leukaemia in 14 patients, hepatosplenic T-cell lymphoma in two patients, anaplastic large cell lymphoma in two patients and intravascular large B-cell lymphoma in one patient. In the presence of intrasinusoidal infiltrates of small lymphocytes, a B-cell phenotype (CD20+, CD76/DBA44+/-) was associated with splenic marginal zone lymphoma whereas intrasinusoidal CD3/CD45RA-positive T-cell infiltrates were strongly suggestive of LGL leukaemia. Intrasinusoidal bone marrow infiltration appears to be a common feature of distinct lymphoma subtypes. Immunohistochemical analysis is essential to detect intrasinusoidal medullary infiltrates (which may be minimal) and should be systematically performed in patients with splenomegaly and peripheral lymphocytosis.
authors.affiliation: Department of Pathology, Gui de Chauliac Hospital, Montpellier, France. v-cortes_martineau@chu-montpellier.fr
authors.forename: Valérie
authors.initials: V
authors.lastname: Costes
authors.forename: Eliane
authors.initials: E
authors.lastname: Duchayne
authors.forename: Jacques
authors.initials: J
authors.lastname: Taib
authors.forename: Christophe
authors.initials: C
authors.lastname: Delfour
authors.forename: Thérèse
authors.initials: T
authors.lastname: Rousset
authors.forename: Pierre
authors.initials: P
authors.lastname: Baldet
authors.forename: Georges
authors.initials: G
authors.lastname: Delsol
authors.forename: Pierre
authors.initials: P
authors.lastname: Brousset
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination / Q000379:methods; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007945:Leukemia, Lymphoid / Q000473:pathology; D017254:Leukemic Infiltration; D008223:Lymphoma / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013160:Splenic Neoplasms / Q000473:pathology