Type I Cryoglobulinemia Associated With Multiple Myeloma: A Case Report.

Cryoglobulinemia is a rare disorder characterized by the presence of serum cryoglobulins, which may result from clonal B-cell expansion (Type I), chronic infections, or autoimmune diseases (mixed cryoglobulinemia: Types II and III). We report the case of an 83-year-old man who fulfilled the diagnostic criteria for Type I cryoglobulinemic vasculitis, presenting with confluent purpuric macules and papules, some ulcerated, along with necrosis. Skin biopsy revealed thrombotic vasculopathy, and laboratory evaluation identified an IgG kappa light-chain monoclonal gammopathy, confirming multiple myeloma as the underlying etiology. Given its rarity and potential for severe complications, early and accurate diagnosis is crucial. In this case, targeted therapy for the underlying plasma cell disorder led to marked improvement of cutaneous lesions and resolution of hyperviscosity symptoms within two months.