Leukemia Research 36 (2012) 250–251 Contents lists available at SciVerse ScienceDirect Leukemia Research jou rnal h omepa g e: www.elsevier.com/locate/leukres Case of the Month Aplastic anemia in association with a lymphoproliferative neoplasm: Coincidence or causality? Michael Medinger a,* , Andreas Buser a , Martin Stern a , Dominik Heim a , Jörg Halter a , Alicia Rovo a , Alexandar Tzankov b , André Tichelli a , Jakob Passweg a a Hematology, University Hospital Basel, Basel, Switzerland b Institute of Pathology, University Hospital Basel, Basel, Switzerland a r t i c l e i n f o Article history: Received 9 June 2011 Received in revised form 7 September 2011 Accepted 12 September 2011 Available online 1 October 2011 Aplastic anemia (AA) is defined as a pancytopenia associated with unexplained bone marrow hypocellularity. The incidence of acquired AA in the Western hemisphere is around 2 new cases per million inhabitants per year [1]. Age distribution shows peaks in children and young adults and in patients aged >60 years. Patients with AA commonly present with anemia, skin or mucosal hemor- rhages and, less frequently, with infection. Acquired AA can be con- sidered in most cases as a T cell-mediated autoimmune disorder, targeted against the hematopoietic progenitors, leading to bone marrow failure [2,3]. Viral infections, drugs, exposure to chemicals, pregnancy, or unknown agents seem to trigger autoimmunity in patients with predisposition. Associations of AA with other autoim- mune diseases have been shown in a retrospective analyzes [4]. Most cases of AA are idiopathic. Rarely, a marrow failure syndrome is associated with an underlying neoplastic disorder [5,6]. First-line treatment is well defined and depends on patient’s age, availability of an HLA-identical sibling donor, and, on the severity of the disease [1]. Family HLA-typing is, therefore, mandatory at diag- nosis of the disease. The standard treatment for a newly diagnosed patient below 40 years with a HLA-matched sibling donor is allo- geneic bone marrow transplantation (BMT). Patients not eligible for BMT should be treated with immunosuppressive therapy (IST) with a combination of antithymocyte globulin (ATG) and cyclosporine A (CSA; ATG + CSA) [7]. Here we describe three cases of SAA who presented as a lymphoproliferative neoplasm (LPN) and where the marrow failure revealed subsequently. The 1st patient was a 74-year-old female, who presented with pancytopenia in 09/2010 (Table 1). Bone marrow cytology was aplastic without dysplasia. Bone marrow biopsy was hypocellular with decreased hematopoiesis, but few cellular areas were densely * Corresponding author at: Hematology, University Hospital Basel, Petersgraben 4 4031, Basel Switzerland. Tel.: +41 61 3286318; fax: +41 61 2654450. E-mail address: medingerm@uhbs.ch (M. Medinger). Fig. 1. Bone marrow histology of case 1, a 74-year-old patient with AA and a lympho- plasmacytic lymphoma. Hypocellular bone marrow with focal, lymphoplasmacytic infiltration. infiltrated with a lymphoplasmacytic lymphoma, with lympho- cytes positive for CD20, CD79a and negative for CD5 (Fig. 1). Additionally, there were small infiltrates of reactive T cells. A small monoclonal IgM kappa gammopathy was present (4.5 g/L). No PNH clone could be found by immunophenotyping and cytogenetic analysis of hematopoietic cells was normal. For the treatment of the lymphoplasmacytic lymphoma the patient received one cycle of rituximab and bendamustine resulting in disappearance of the paraprotein. However, there was a worsening of the pancytopenia, with neutrophil counts of 0.10 × 10 9 /L, and platelet counts below 20 × 10 9 /L (Table 1). The diagnosis of severe AA was done. A treatment with CSA was started. After 4 months of therapy with CSA, first the neutrophils (max. 1.3 × 10 9 /L) and thereafter the hemoglobin levels increased (100 g/L). The platelets are ongoing low and the patient still needs platelet transfusions however with longer intervals. The 2nd patient is a 54-year-old male, who was diagnosed with unclassifiable small B-cell lymphoma and pancytopenia in 11/2003 0145-2126/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.leukres.2011.09.008