Extramedullary myelomatous disease is an aggressive condition where clonal plasma cells proliferate outside the bone marrow, allowing independent survival. This state is generally associated with negative outcomes. A 65-year-old woman presented with progressive bilateral hypochondrial pain, was initially misattributed to an inflammatory etiology, and was consequently managed with corticosteroid therapy. A bone marrow biopsy was offered after further deterioration confirming plasma cell myeloma. Afterward, 18 F-FDG PET/CT revealed medullary and extramedullary hepatosplenic and thyroid cartilage involvement, concluding an overall picture of an atypical and extensive extramedullary myelomatous disease.