A healthy 40-year-old active-duty male soldier presented with a painless groin mass, which he had noted a few weeks earlier. He denied having constitutional symptoms, recent infection, inflammatory joint symptoms, or a history of trauma.
The physical examination was notable for an immobile firm mass in the patient’s right inguinal area. There were no other areas of lymphadenopathy, and the results of a genitourinary examination were normal.
Radiographs of the patient's right hip and pelvis were obtained; the results were unremarkable. An ultrasonogram (top) and an MRI scan (bottom) were obtained. What do they show?
What is your diagnosis?