Inguinal endometriosis is a less common form of endometriosis. Therefore, there is no consensus regarding its pathogenesis or treatment. In this study, we retrospectively reviewed the pathogenesis and treatment of six cases of inguinal endometriosis in our facility between 2009 and 2019. The pathogenesis of inguinal endometriosis is believed to involve hematogenous and lymphogenous extensions, as well as direct infiltration from the canal of Nuck or inguinal hernia. However, in our cases, the endometriotic lesions might have spread intravascularly from the uterine cavity. The lesions in our all cases were found as nodular or pointed hyperintensities on T1-weighted magnetic resonance imaging. In addition, all the patients experienced swelling and pain in the inguinal region during menstruation. Complete resection is often performed
however, hormonal therapy is administered to patients who do not undergo surgery, or to avoid recurrence. In our cases, dienogest was effective in reducing inguinal endometriotic lesions, improving pain, and preventing recurrence.