Inguinal endometriosis is an unusual extrapelvic site for endometriosis.
The estimated incidence is as around 0.07% among those having endometriosis 4. There is an increased right sided predilection (around 80-90 %of reported cases) 9.
As with endometriosis in general it is characterised by the presence of endometrial glands and stroma in the inguinal region. Direct extension of endometrial tissue along the round ligament is considered a possible pathogenesis.
Patients may present with a tender groin mass which fluctuates with the menstrual cycle. Concomitant pelvic endometriosis may be present.
Usually seen a mass or cluster of masses of variable size and shape in the inguinal region. They may be solid, cystic or have a combination 9.
Typically signal characteristics are similar to endometriosis elsewhere. But in a proportion of cases inguinal endometriosis, MRI features can by atypical and non-specific: e.g. intermediate or high signal intensity on T2- weighted images.
MRI may show better anatomical delineation as well as contiguity with the round ligament.
Treatment and prognosis
Surgery is usually considered the treatment of choice 5. In those considered for surgical resection, excision of the extraperitoneal portion of the round ligament is also recommended 7.
Clinically it may be misdiagnosed as an inguinal hernia 5.
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