A hole in the skull: CT manifestations of a solitary plasmacytoma in skull
Abstract
Plasmacytoma can present as multiple myeloma, solitary plasmacytoma of the bone (SPB), or extramedullary plasmacytoma. SPB is a rare entity that composes of malignant plasma cells and involves the bone to form only one or two lesions without evidence of disease dissemination. It accounts for only 4% of malignant plasma cell tumors. We report a case of SPB in the skull in a 59-year-old male. CT scan revealed an 8 cm × 9 cm osteolytic lesion on the scalp of skull with a well demarcated margin. A cake-like mass was revealed at CT soft tissue window. The mass was completely excised and histological examination revealed plasmacytoma. The diagnosis of SPB was established after ruling out multiple myeloma.
Keywords
Plasmacytoma; multiple myeloma; solitary plasmacytoma of the bone; extramedullary plasmacytoma; skull
A 59-year-old man presented a painless palpable soft hollow on the scalp of skull. The medical history was unremarkable. Palpation showed a sunken area at the frontal bone. CT scanning and three-dimension reformation were performed. A large size osteolytic lesion measured 8 cm × 9 cm was demonstrated (Figure 1, 2). It was well demarcated with small remaining bone fragments. CT Soft tissue window revealed a cake-like mass (Figure 3). Three-dimension reformation showed a big hole at the frontal bone (Figure 4). The mass was completely removed. Histological examination showed the tumor was composed of plasma cells and a diagnosis of plasmacytoma was suggested (Figure 5). No monoclonal proteins were found in the serum or urine, and bone marrow biopsy was normal. Skeletal scintigraphy did not detect any other lesions. Therefore, multiple myeloma was ruled out and the diagnosis of SPB was established.
