IgD Multiple Myeloma: a Rare and Aggressive Entity: Report of Three Clinical Cases and Review of the Literature

IgD multiple myeloma is an exceptionally rare subtype, accounting for less than 2% of all multiple myeloma cases.

We report three cases diagnosed at the central biochemistry laboratory of the Ibn Sina University Hospital in Rabat, Morocco, involving young patients with a mean age of 38 years.

All cases showed a marked male predominance. Clinically, patients presented with frequent bone involvement and renal impairment. Laboratory findings consistently revealed anemia, Bence-Jones proteinuria with a predominance of lambda light chains, hypercalcemia, and variable bone marrow infiltration by plasma cells, reaching up to 88%. The diagnosis is often challenging due to the subtle or absent monoclonal bands on serum protein electrophoresis.

Compared to existing literature, our series aligns with the known features of IgD myeloma, including male predominance, lambda light chain involvement, anemia, renal dysfunction, and lytic bone lesions. However, it is distinguished by the unusually young age of the patients, highlighting the need for heightened clinical suspicion in younger individuals presenting with such symptoms.