A solitary lytic rib lesion mimicking primary Chest Wall malignancy as the initial presentation of multiple myeloma

Multiple myeloma is predominantly observed in the geriatric population and accounts for approximately 10% of all hematologic malignancies. It typically presents with multiple bone lesions and clinical features fulfilling the CRAB criteria (hyperCalcemia, Renal failure, Anemia, and Bone involvement). Herein, we present the case of an 82-year-old patient who presented with a solitary lytic rib lesion in the left hemithorax. The patient exhibited only bone pain among the CRAB features, and systemic radiological evaluation revealed no additional lesions. The initial clinical impression was that of a primary malignancy of the thoracic wall. A diagnosis of multiple myeloma was confirmed based on the histopathological evaluation of both the solitary lytic rib lesion and bone marrow samples.