Multiple myeloma (MM) is a plasma cell malignant disorder with variable clinical presentations. Because MM is the most prevalent hematologic malignancy among Black patients, a high index of suspicion is often applied in this population. However, premature diagnostic closure may occur when initial findings appear consistent with MM, while conflicting information is overlooked. This case describes a 46-year-old Black man initially diagnosed with active MM but ultimately found to have active sarcoidosis and smoldering myeloma. This case illustrates the importance of recognizing cognitive bias and considering granulomatous disease in the differential diagnosis of hypercalcemia, lytic lesions, and systemic abnormalities.
Chen et al. (2026) studied this question.