Essential Thrombocythaemia with Concomitant Waldenström Macroglobulinaemia: Case Report and Literature Review

Abstract

Essential thrombocythaemia (ET) and Waldenström macroglobulinaemia (WM) are two distinct disorders. Studies have reported several cases of myeloproliferative neoplasms (MPNs) with concomitant plasma cell dyscrasia. However, there were no reported cases of ET with concomitant WM to date. Here, we present a 55-year-old Chinese man with thrombocytosis and raised immunoglobulin level. Further investigations led to a diagnosis of ET and coexistent WM. Next-generation sequencing (NGS) of his bone marrow identified 3 mutated genes: JAK2 V617F, MYD88 L265P, and ATM F1036L. After being treated with pegylated interferon and low-dose aspirin, his platelet count normalized and immunoglobulin M (IgM) level reduced. To the best of our knowledge, this is the first reported case of dual pathology ET with WM.

Keywords: Janus kinase 2; Waldenström macroglobulinaemia; myeloid differentiation factor 88; myeloproliferative neoplasm.

Figure 1

Histological examination of the bone marrow. (A) The bone marrow aspiration shows an excess of platelets (white arrow) and a lymphoplasmacytoid lymphocyte (black arrow), which has a shoe shaped cell with pale blue cytoplasm and an irregular nucleus (giemsa staining; ×1000). (B) A lymphoplasmacytoid lymphocyte (black arrow) with pale blue cytoplasm and an eccentric nucleus (giemsa staining; ×1000). (C) The bone marrow trephine shows increased numbers of lymphocytes and an excess of mature megakaryocytes with hyperlobulated nuclei (black arrow; hematoxylin and eosin staining; ×400).

Figure 2

Flow cytometry immunophenotyping result of the bone marrow. The flow cytometry confirmed the presence of monoclonal B lymphocytes, which were positive for CD19, CD20 and cell membrane light chain kappa, but negative for CD5, CD10 and CD23. Blue dots denote lymphocytes.