F-18 fluorodeoxyglucose positron emission tomography/computed tomography imaging in left thigh intramuscular myxoma.

We report F-18 FDG PET-CT appearance of biopsy-proven intramuscular myxoma (IM) in a 69-year-old woman who presented with a left thigh mass. The tumor appears as a well-defined, hypodense mass with thin septation on CT images and mild uptake on PET images. IMs are rare benign myxoid tumors characterized by a paucity of cells, diminished vascularity, and minimal mitotic figures. They most often present as slow-growing, painless, deep-seated intramuscular masses. The mainstay of treatment is surgical resection.