Suppression of F-18 fluorodeoxyglucose uptake in benign uterine leiomyomas with danazol

A 40-year premenopausal woman was referred by her treating oncologist for F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) to rule out disease recurrence or metastasis. She had completed therapy for Hodgkin lymphoma (Stage IIA) 1 year earlier. Post-therapy gallium-67 study showed no evidence of residual disease and the patient was on regular follow-up. The only abnormality detected on the FDG-PET/CT study was a focus of abnormal FDG accumulation in the pelvis, suprapubically. Fused PET-CT localized the uptake to the uterine myometrium in the fundal region posteriorly corresponding to mild inhomogeneity in attenuation with a bulky uterus on CT. MRI of the pelvis confirmed the presence of a uterine leiomyoma in the fundal region. The patient was put on danazol (200 mg twice daily for 14 days) and a repeat PET-CT of the pelvis was done after 14 days, which revealed complete disappearance of FDG uptake in the leiomyoma. This proved that F-18 FDG uptake in the leiomyoma was probably related to its vascularity.