With the right patient history, a right lower abdominal wall lesion is compatible with abdominal wall endometriosis related to C-section scar. 

Abdominal wall endometriosis is the most common location of extrapelvic endometriosis and usually occurs after cesarean section. A wide spectrum of disorders should be considered in the differential diagnosis including neoplasms such as a sarcoma, desmoid tumor, or metastasis and non-neoplastic causes such as a suture granuloma, hernia, hematoma, or abscess. However, abdominal wall endometriosis should always be the prime consideration in patients with an abdominal wall mass near a cesarean section scar and the classical history of cyclical pain.