DIAGNOSIS IN ONCOLOGY Arthur Skarin, MD, Consultant Editor Unusual Presentations of Lymphoma CASE 1. SEA-BLUE HISTIOCYTES IN NON-HODGKIN’S LYMPHOMA A previously healthy 52-year-old Laotian woman presented with a recent history of mild postprandial epigastric discomfort and fatigue. Her physical examination revealed a spleen 3 cm below the left costal margin and no lymphadenopathy. The complete blood cell (CBC) count showed a hemoglobin level of 11.7 g/dL, a hematocrit level of 34.4%, a platelet count of 68,000/mm 3 , and a WBC count of 3,400/mm 3 with a normal differential count. The peripheral-blood smear was unremarkable. Computed tomography showed a spleen span of 15 cm with minimal lymphadenopathy in the inguinal, anterior mediastinal, and aortopulmonary areas. Bone marrow examination disclosed multiple lymphoid aggregates with some larger lymphocytes in a germinal center–like configuration, suggesting bone marrow involvement by follicular lymphoma. Also noted was a prominent population of phagocytic histiocytes, the so-called sea-blue histiocytes (Figs 1 and 2). They were characterized by a single eccentric nucleus and cytoplasm containing large blue lysosomal granules on Giemsa stain. Flow cytometry revealed lymphocytosis with predominance of small, mature-appearing B lymphocytes (Fig 3) expressing CD19 and CD20 antigens and an immunoglobulin light-chain kappa/lambda ratio of 59:1. These cells were negative for CD5 and CD10. A diagnosis of follicular low-grade lymphocytic lymphoma was established. The primary syndrome of sea-blue histiocytosis 1 is characterized by splenomegaly, thrombocytopenia, and a relatively benign clinical course. Clusters of sea-blue histiocytes are observed in the spleen, liver, and bone marrow. Although the pathogenesis of the stored material is not well established, phospholipids, glycosphingolipids, and ceroids have been identified. Sea-blue histiocytes containing other types of lipids or glycolipids have been described in the setting of inherited enzyme deficiencies, such as Nieman-Pick disease, and in association with hyperlipidemia, total parenteral nutrition, chronic granulomatous disease, Takayasu arteritis, and hepatic porphyria. Several hematologic conditions, including idiopathic thrombocytopenic purpura, 2 chronic granulocytic leukemia, 3 lymphoma, 4 mycosis fungoides, 5 primary myelofibrosis, 6 and myelodysplastic syndromes, 7 have also been associated with sea-blue histiocytosis in the bone marrow. Although this is the third case of non-Hodgkin’s lymphoma presenting with sea-blue histiocytes, this association remains speculative. Thein H. Oo, Leo S. Aish, and Hani Hassoun St Elizabeth’s Medical Center of Boston, Tufts University School of Medicine, Boston, MA Copyright © 2002 American Society of Clinical Oncology Fig 1. Fig 2. 1942 Journal of Clinical Oncology, Vol 20, No 7 (April 1), 2002: pp 1942-1947 Downloaded from jco.ascopubs.org on June 11, 2016. For personal use only. No other uses without permission. Copyright © 2002 American Society of Clinical Oncology. All rights reserved.