Bone marrow involvement in lymphomas with hemophagocytic syndrome at presentation - A clinicopathologic study of 11 patients in a western institution

Hemophagocytic syndrome (HPS) is a clinicopathologic syndrome that can reve al a non-Hodgkin's lymphoma. The pathologic features of lymphoma associated with HPS remain ill defined. We studied 11 lymphomas associated with HPS o n initial bone marrow biopsies, consecutively diagnosed during a 6-year per iod in a Western institution. There were seven diffuse large B-cell lymphom as (DLBCLs), three T-cell lymphomas (one peripheral T-cell lymphoma unspeci fied, two hepatosplenic gamma delta T-cell lymphomas [HS gamma delta TLs]), and one aggressive NK-cell lymphoma/leukemia (NKL). These lymphomas shared common clinicopathologic features with a systemic presentation, a poor out come (nine patients died within 2 years), and a mild interstitial lymphoid infiltrate of the bone marrow at presentation in nine patients. This equivo cal lymphoma infiltrate was blending with normal hematopoietic cells, and C D20 and CD3 immunolabelings were essential for its detection. A high number of reactive T (CD3+) cells, most often with a predominant cytotoxic (CD8TiAl+) phenotype, was present in all DLBCLs. By in situ hybridization, Epst ein-Barr virus was detected in neoplastic cells of three cases (one DLBCL, one HS gamma delta TL, and one NKL), which also showed serum viral DNA. Pol ymerase chain reaction studies disclosed HHV6 DNA sequences in tumor tissue s of two DLBCLs, whereas HHV8 DNA was not detected. Because tumor mass indi cative of lymphoma was not striking in most patients, bone marrow biopsy ap pears to be of great value for the diagnosis of an HPS-associated lymphoma, which may be, in Western patients, of Bas well as T- or NK-cell type. Immu nostaining for CD3 and CD20 is essential to identify the common subtle lymp homa involvement. Together with a better understanding of the pathogenic pr ocesses, an early diagnosis may improve the prognosis of HPS-associated lym phoma.