Two Cases of Heavy Chain MGUS.

Jan Van Keer,Gregor Verhoef,Björn Meijers,Koen Poesen,Michel Delforge

doi:10.1155/2016/8749153

Abstract

Heavy chain diseases are rare variants of B-cell lymphomas that produce one of three classes of immunoglobulin heavy chains, without corresponding light chains. We describe two patients with asymptomatic heavy chain monoclonal gammopathy. The first patient is a 51-year-old woman with alpha paraprotein on serum immunofixation. The second case is a 46-year-old woman with gamma paraprotein on urine immunofixation. Neither patient had corresponding monoclonal light chains. Workup for multiple myeloma and lymphoma was negative in both patients. These two cases illustrate that heavy chain monoclonal gammopathy can exist in the absence of clinically apparent malignancy. Only a few reports of “heavy chain MGUS” have been described before. In the absence of specialized guidelines, we suggest a similar follow-up as for MGUS, while taking into account the higher probability of progression to lymphoma than to myeloma.

Highlights

Heavy chain diseases are characterized by the presence of monoclonal heavy chains without light chains in serum and/or urine [1]
We describe two patients with asymptomatic heavy chain monoclonal gammopathy, who meet the criteria of “monoclonal gammopathy of undetermined significance” (MGUS) [6]
Heavy chain diseases are rare variants of B-cell lymphomas characterized by the presence of monoclonal heavy chains, alpha, gamma, or mu, without corresponding light chains

Summary

Introduction

Heavy chain diseases are characterized by the presence of monoclonal heavy chains without light chains in serum and/or urine [1]. They are rare variants of B-cell lymphomas that produce one of three classes of immunoglobulin heavy chains: alpha, gamma, or mu [2,3,4]. The clinical manifestations vary with the heavy chain isotype and range from an asymptomatic presentation to aggressive lymphoma [5]. We describe two patients with asymptomatic heavy chain monoclonal gammopathy, who meet the criteria of “monoclonal gammopathy of undetermined significance” (MGUS) [6]

Case 1

Case 2

Findings

Discussion

Conclusion