IgM Multiple Myeloma Presenting As Hyperviscosity Syndrome with Isolated Skin Manifestation

Background:

Immunoglobulin M-producing multiple myeloma (IgM MM) accounts for less than 1% of all myeloma cases. Because the disorder is rare,its clinical characteristics and long-term prognosis remain unknown. Hyperviscosity occurs from pathologic changes of either cellular or protein fractions of the blood such as are found in MM (particularly IgA and IgG3) and other diseases.

Case Presentation

A 65-year-old male smoker presented to emergency room (ER) with headache, dizziness, shortness of breath, symmetrical finger pain, nose bleeds, and blood in stool. On lab work hemoglobin was 7.9 gm/dl. Review of the peripheral blood smear showed atypical lymphocytes. CT chest showed left axillary and supraclavicular lymphdenopathy. Serum protein was 13 gm/dl, Serum protein electrophoresis showed a monoclonal IgM kappa gammopathy with UIEP confirming the bence jones proteinuria. A bone marrow biopsy showed about 80% cellularity with diffuse and solid neoplastic plasma cell infiltrates that were CD138+, CD20- and CD3-. Flow cytometric analysis of the bone marrow aspirate demonstrated a small fraction of clonal plasma cell population that were CD38+, CD138+, CD45-, and CD56-, Fluorescent in Situ Hybridization confirmed neoplastic plasma cells with kappa light chain restriction, and cyclinD1-. On examination, the patient had a erythematous skin changes and edematous bilateral symmetrical finger findings.

Discussion:

MM with IgM gammaglobulin is a rather distinct subtype of MM displaying clinical and pathologic features of both MM and WM. The clinical presentation of WM is similar to that of MM except that organomegaly is common in WM but is uncommon in MM and lytic bone disease and renal disease are uncommon in WM but are common in MM.

The criteria for diagnosis of IgM myeloma (and its differentiation from WM) requires the presence of either lytic bone lesions and/or evidence of the t(11;14) translocation. It is also characterized by negative CD20, D56 and CD117 phenotype. All the reported cases of IgM myeloma had been treated with melphalan and prednisolone with suboptimal results. Some patients were treated with VAD (vincristine, adriamycin and dexamethasone) regimen, others with CTD protocol. The results were similar to the MP regimen. Radiotherapy was mainly used as palliative measure.

Conclusion:

Our case suggests that IgM multiple myeloma can presents as hyperviscosity syndrome with isolated skin manifestation and may have unique clinical characteristics.