Isolated inguinal endometriosis. Case report with ultrasonographic preoperative diagnosis

Inguinal endometriosis is rare and accounts for 0.3-0.6% of patients affected by endometriosis. A correct preoperative diagnosis is rare. Diagnosis is frequently made by histologic examination. A 36-year-old nulliparous woman presented with a painful mass in her right groin of 2 years duration. The pain fluctuated according to the menstrual period. Physical examination revealed an elastic hard mobile mass measuring 2 x 2 cm in the right inguinal region. Ultrasound examination confirmed a hypoechoic tumor in the right inguinal region with poorly defined boundaries and perilesional and intralesional vascular flow suspect for endometriosis. Wide excision of the lump with a part of the round ligament was carried out. Histology showed endometrial glands and stroma within the fibrous tissue. The patient had an uneventful recovery and was discharged the next day. After surgery, the pain disappeared completely. No signs of recurrence occurred at approximately 16 months after the surgery. Although rare, extrapelvic endometriosis should be considered in the differential diagnosis in women of reproductive age presenting with an inguinal mass, especially if the groin mass is associated in size and tenderness with menstrual variability. US appearance is very useful in diagnosis so ultrasonography can be considered the examination of choice.