Integrating salient imaging findings with clinical history is crucial when approaching the diagnosis of subcutaneous soft-tissue masses. The diagnosis of endometriosis should be entertained when soft-tissue masses are seen in the distribution of a cesarean section scar in a woman of reproductive age. Pain, particularly with a cyclic pattern, is highly suggestive of endometriosis. If endometriosis is suspected on CT or ultrasound, MRI can be performed for further evaluation. Definitive diagnosis is made with biopsy. Because subcutaneous nodules are so amenable percutaneous biopsy, imaging features, although of interest, are somewhat ancillary to the diagnostic workup.