Deep pelvic endometriosis: a radiologist's guide to key imaging features with clinical and histopathologic review

While endometriosis typically affects the ovaries, deep infiltrating endometriosis can affect the gastrointestinal tract, urinary tract, and deep pelvis, awareness of which is important for radiologists. Symptoms are nonspecific and can range from chronic abdominal and deep pelvic pain to nausea, vomiting, diarrhea, constipation, hematuria, and rectal bleeding. Ultrasound and computed tomography may show nonspecific soft-tissue density masses causing bowel obstruction and hydronephrosis. This constellation of presenting symptoms and imaging evidence is easily mistaken for other pathologies including infectious gastroenteritis, diverticulitis, appendicitis, and malignancy, which may lead to unnecessary surgery or mismanagement. With this, deep pelvic endometriosis should be considered in the differential diagnosis in a female patient of reproductive age who presents with such atypical symptoms, and further work up with magnetic resonance imaging is imperative for accurate diagnosis, treatment selection, and preoperative planning.