Diagnostic usefulness of FDG-PET/CT in advanced malignant lymphoma of the uterus: report of two cases.

Summary Malignant lymphoma of the uterus is difficult to diagnose because of its rarity and nonspecific symptoms. However, recently, 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become an important non-invasive diagnostic tool for the management of lymphoma patients. The authors report two cases of malignant lymphoma of the uterus, in which FDG-PET/CT was useful for diagnosis. Examination using ultrasonography or magnetic resonance imaging (MRI) demonstrated a normal-sized uterus and normal endometrium, but FDG-PET/CT showed FDG accumulation in the uterine body in both cases. Endometrial biopsy revealed diffuse large B-cell lymphoma, and chemotherapy with rituximab, cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) was initiated immediately. Primary malignant lymphoma of the female genitalia is reported to be rare. The present authors' experience with FDG-PET/CT suggests that malignant lymphoma of the female genitalia (including metastasis) may not be as rare as previously reported. Uterine malignant lymphoma may be overlooked by the examination of ultrasound, CT, or MRI.