Extramedullary Plasmacytoma: Hepatic Lesions and Enlarged Lymph Nodes With Intense 18F-FDG Uptake Mimicking Metastases.

A 66-year-old woman having intermittent abdominal distention for 2 months was referred to our hospital. An enhanced abdominal CT scan showed multiple hepatic lesions, suspected of metastases. An 18F-FDG PET/CT scan, which was performed to seek primary tumor, showed multiple lesions with intense 18F-FDG uptake in the liver and lymph nodes located in cardiophrenic angle, abdominal cavity, and retroperitoneal space. All 18F-FDG-avid lesions were suspected of metastases. However, no suspected primary tumor was identified by the 18F-FDG PET/CT scan, which prompted the liver biopsy. Pathologic analysis revealed the presence of plasmacytoma.