Emergent and unusual presentations of endometriosis: pearls and pitfalls

The purpose of this pictorial essay is to highlight atypical and unusual presentations of endometriosis that can be missed or misinterpreted in the emergency setting. Although endometriosis is a chronic disease, it can present acutely with symptoms and imaging mimicking more common acute gynecologic, gastrointestinal, or urinary conditions as well as neoplasms. Furthermore, patients may present emergently prior to an established diagnosis of endometriosis. Here, we present a range of cases including endometrioma rupture and infection, urinary tract involvement and obstruction, bowel obstruction, appendicitis, gastrointestinal infiltration, abdominal masses, and thoracic involvement. Pelvic ultrasound and MRI are the most valuable imaging modalities in the assessment of endometriosis. CT findings are non-specific, but given the widespread use of CT in emergency settings, it is important to recognize CT findings suggestive of the diagnosis in the right clinical setting.