A case of benign immunoglobulin D monoclonal gammopathy of undetermined significance with 26 years of follow‐up

Abstract

AbstractThe presence of a serum immunoglobulin D (IgD) monoclonal protein (M‐protein) is seen in < 1% of patients with monoclonal gammopathies and is usually indicative of a malignant plasma cell disorder. Only a few cases of well‐documented benign monoclonal gammopathy of undetermined significance (MGUS) of IgD subtype have been reported, and only 2 of those had over 5 years of follow‐up at the time they were reported. Herein we describe longer‐term follow‐up of one of those 2 patients who has subsequently passed away from unrelated causes but never developed multiple myeloma or amyloidosis after 26 years of follow‐up. Although IgD MGUS is extremely rare, this case confirms that presence of an IgD M‐Protein is not always synonymous with a malignant plasma cell process.