Abstract: Skin mass is a common disease in dermatology clinic, the diagnosis often needs the assistance of ultrasound, but sometimes the role of ultrasonic is limited, and the histopathological biopsy is still needed. We report a young female with abdominal mass. Ultrasound showed hypoechoic nodules, and CDFI showed a small amount of blood flow signal without obvious significance. The mass was located near the incision of cesarean section. The patient disclosed that the size of the mass was related to the menstrual cycle, and was referred to the obstetrical department for diagnosis and treatment. Post-surgical pathology results confirmed ectopic uterine glands and interstitial tissue, leading to a diagnosis of abdominal wall endometriosis.

Key words: skin mass, abdominal wall endometriosis, caesarean