Abstract
2715
Objectives Patients diagnosed with a solitary plasmacytoma can actually have multiple myeloma (MM). The purpose of this study is to measure how often patients presenting with a plasmacytoma have multiple lesions found on a PET/CT scan, quantify how active plasmacytomas are compared to normal tissues and evaluate whether high activity predicts multiple lesions.
Methods A retrospective review was conducted of patients undergoing a PET/CT scan for the indication of a solitary plasmacytoma between 1995- 2011. The report and PET/CT scan was reviewed to determine whether a solitary plasmacytoma or MM was present. A standard uptake value (SUV) was measured for the solitary plasmacytoma and analyzed for correlation to the MM diagnosis. The SUV of the liver was also tabulated.
Results This study identified 28 patients (19 males; 9 females) with a mean age of 58.7 years (range 24-77). A solitary plasmacytoma was found in 18 patients where the remainder of the PET/CT was negative. In 10 patients (35.7%) multiple lesions were found leading to the diagnosis of MM. The solitary plasmacytoma maximum SUVs varied over a wide range from 3.0 to 28.4 (mean 8.24 ± 6.11). The plasmacytomas were consistently more active than the patient’s liver (mean 2.94 ± 0.50).). There was no correlation between the plasmacytoma SUV and the presence of multiple PET/CT lesions indicative of MM (p=0.85).
Conclusions Over one third of patients presenting with a solitary plasmacytoma have MM identified on PET/CT. The presence of high FDG uptake in the plasmacytoma does not predict the diagnosis of MM