Development of Polycythaemia rubra vera following Treatment for Centroblastic Lymphoma

Dr. P. Harrison, Department of Haematology, Birmingham Heartland’s Hospital, Bordesley Green East, Birmingham B9 5SS (UK) A 74-year-old woman developed polycythaemia rubra vera (PRV) with deletion of the long arm of chromosome 20 (20q-) 11 years after successful treatment of high grade non-Hodgkin’s lymphoma (NHL). The 20qabnormality is a common finding in PRV but has also been described in lymphomas. To our knowledge this is the first reported case of PRV following treatment of NHL. A 62-year-old woman presented with weight loss and left inguinal lymphadenopathy in 1982. A lymph node biopsy showed diffuse centroblastic NHL. Other investigations included a full blood count (Hb 11.3 × 109/1, PCV 0.37, WBC 6.2 × 109/1, platelets 454 × 109/1), a normal bone marrow aspirate and trephine and a normal abdominal ultrasound. She received 7 courses of combination chemotherapy (cyclophosphamide, Adriamycin, vincristine, prednisolone and methotrexate) and has since remained in remission. By 1994 her Hb had risen to 17.1 g/dl with PCV 0.53. Further investigation showed a raised leucocyte alkaline phosphatase score, a raised red cell mass, a raised serum B∏ and normal arterial oxygen saturation. Bone marrow aspiration and biopsy showed a hypercellu-lar marrow with increased megakaryocytes and increased erythropoi-esis. Cytogenetic analysis showed 46XX, del(20)(qll) [12], 46XX [8]. Although PRV has not been reported after treatment of NHL, the development of both lymphoproliferative and other myeloproliferative disorders in patients with PRV is well recognised. The transformation of PRV to acute lymphoblastic leukaemia (ALL) is described in five separate reports which were reviewed by Neilson et al. [1]. Chronic lymphocytic leukaemia has developed in patients with pre-existing PRV and has presented simultaneously [2, 3]. The development of NHL in a case of PRV is the subject of a single report [2]. Myelodysplastic syndromes (MDS), acute myeloid leukaemia (AML) and lymphomas have all been described following therapy of lymphomas [4]. Chromosomal abnormalities are usual in secondary MDS and AML, occurring in up to 93% of cases, and 20qis a recognised, though rare, finding in both MDS and AML. A recent report has shown that the 20qabnormality can occur simultaneously in both myeloid and lymphoid cells in MDS [5]. In untreated PRV an abnormal karyotype is found in approximately 14% of cases, the commonest defect being 20q-.