Coexistence of Wild-Type Transthyretin Cardiac Amyloidosis and Monoclonal Gammopathy in a Patient With Polycythemia Vera

Polycythemia vera is a type of myeloproliferative neoplasm characterized by panmyelosis, with a predominant increase in erythrocyte mass. In contrast, monoclonal gammopathy of undetermined significance is classified as a premalignant plasma cell disorder and is characterized by elevated levels of monoclonal γ-globulin without associated bone lesions or clinical symptoms. Here, we present a case of the concurrent presence of wild-type transthyretin cardiac amyloidosis—not the amyloid light-chain type—and monoclonal gammopathy of undetermined significance in a patient with polycythemia vera. This case underscores the crucial importance of preforming histologic subtyping to ensure accurate diagnosis in older patients with undiagnosed cardiac amyloidosis.