Extramedullary Plasmacytoma Hepatic Lesions and Enlarged Lymph Nodes With Intense F-18-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 F-18-FDG PET/CT scan, which was performed to seek primary tumor, showed multiple lesions with intense F-18-FDG uptake in the liver and lymph nodes located in cardiophrenic angle, abdominal cavity, and retroperitoneal space. All F-18-FDG-avid lesions were suspected of metastases. However, no suspected primary tumor was identified by the F-18-FDG PET/CT scan, which prompted the liver biopsy. Pathologic analysis revealed the presence of plasmacytoma.