A case of retroperitoneal extramedullary plasmacytoma with multiple metastases

Extramedullary Plasmacytoma of the Retroperitoneum Detected on 18 F-FDG PET/CT

ABSTRACT

Solitary retroperitoneal extramedullary plasmacytoma is a rare neoplasm. A 67-year-old man presented with abdominal pain and left leg weakness. Abdominal CT revealed a large mass in the left retroperitoneum, which demonstrated increased metabolic activity on subsequent 18 F-FDG PET/CT imaging. Furthermore, the patient's serum protein electrophoresis showed positive M-protein results. Pathological examination of the biopsied specimen confirmed the diagnosis of extramedullary plasmacytoma.

CT features of abdominal plasma cell neoplasms

The aim of this study was to describe the CT features of abdominal plasma cell neoplasms. We reviewed CT imaging findings in 11 patients (seven men, four women; mean age 62 years) with plasma cell neoplasms and abdominal involvement. Helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material. Images were analyzed in consensus by two radiologists. Diagnoses were made from biopsy, surgery and/or clinical follow-up findings. Multiple myeloma was found in seven patients and extramedullary plasmacytoma in four patients. All patients with multiple myeloma had multifocal disease with involvement of perirenal space (4/7), retroperitoneal and pelvic lymph nodes (3/7), peritoneum (3/7), liver (2/7), subcutaneous tissues (2/7) and kidney (1/7). In three of the four patients with extramedullary plasmacytoma, a single site was involved, namely stomach, vagina and retroperitoneum. In the fourth patient, a double site of abdominal involvement was observed with rectal and jejunal masses. Plasma cell neoplasm should be considered in the differential diagnosis of single or multiple enhancing masses in the abdomen or pelvis. Abdominal plasma cell neoplasms were most frequently seen as well-defined enhancing masses (10/11).

Diffuse cutaneous plasmacytomas demonstrated on gallium-67 imaging

Gallium-67 scanning is a useful tool to search for infectious foci and malignant tumors. Multiple myeloma is one clinical indication for gallium-67 tumor survey. Here, we report a rare case of diffuse multiple cutaneous plasmacytomas from recurrent multiple myeloma, demonstrated by whole-body gallium-67 scan.

Gallium-67 demonstration of extensive soft-tissue involvement of multiple myeloma

A 46-year-old woman with multiple myeloma presented with neurological symptoms in the right upper extremity. After MR imaging of the cervical spine failed to show the cause of her symptoms, Ga-67 scintigraphy demonstrated increased uptake in multiple areas including the right supraclavicular region and bilateral lower extremities. Histology of the specimen obtained from the left thigh proved soft-tissue involvement of myeloma, and extensive extramedullary involvement was diagnosed. Radiotherapy to the right supraclavicular mass relieved her symptoms. Although Ga-67 scintigraphy is generally considered of limited value in multiple myeloma, this modality contributed to the development of an appropriate strategy in this patient with extensive extramedullary involvement.