Multiple myeloma in a 27-year-old: A rare presentation with cutaneous involvement and literature insights

Multiple myeloma (MM) is a hematological malignancy marked by the abnormal proliferation of plasma cells that invade the bone marrow and, in most cases, secrete a monoclonal protein. While typically diagnosed in older individuals with an average age of 70, MM is rarely observed in young adults. Here, we present a unique case of MM in a 27-year-old
man with nodular lesions on the trunk, histologically confirmed as cutaneous MM. Laboratory investigations revealed
acute renal impairment, hypercalcemia, and the presence of IgG-Lambda paraprotein. The myelogram confirmed plasmacytosis in more than 12% of the bone marrow mononuclear cells. This case highlights the relevance of considering MM in the differential diagnosis of young patients with unusual cutaneous manifestations.