Extrapelvic Endometriosis: A Systematic Review

To conduct a systematic review of the literature on patients with extrapelvic deep endometriosis. A thorough search of the PubMed/Medline, Embase, and Cochrane databases was performed. Studies in the last 20 years that reported on primary extrapelvic endometriosis were included (PROSPERO registration number CRD42019125370). The initial search identified 5465 articles, and 179 articles, mostly case reports and series, were included. A total of 230 parietal (PE), 43 visceral (VE), 628 thoracic (TE), 6 central nerve system, 12 extrapelvic muscle or nerve, and 1 nasal endometriosis articles were identified. Abdominal endometriosis was divided into PE and VE. PE lesions involved primary lesions of the abdominal wall, groin, and perineum. When present, symptoms included a palpable mass (99%), cyclic pain (71%) and cyclic bleeding (48%). Preoperative clinical suspicion was low, the use of tissue diagnosis was indeterminate (25%), and a few (8%) malignancies were suspected. Surgical treatment for PE included wide local excision (97%), with 5% recurrence and no complications. Patients with VE involving abdominal organs – kidneys, liver, pancreas, and biliary tract – were treated surgically (86%) with both conservative (51%) and radical resection (49%), with 15% recurrence and 2 major complications reported. In patients with TE involving the diaphragm, pleura, and lung, isolated and concomitant lesions occurred and favored the right side (80%). Patients with TE presented with the triad of catamenial pain, pneumothorax, and hemoptysis. Thoracoscopy with resection followed by pleurodesis was the most common procedure performed, with 29% recurrence. Adjuvant medical therapy with gonadotropin-releasing hormone was administered in 15% of cases. Preoperative magnetic resonance imaging was performed in all cases of nonthoracic and nonabdominal endometriosis. Common symptoms were paresthesia and cyclic pain with radiation. Surgical resection was reported in 84%, with improvement of symptoms. Extrapelvic endometriosis, traditionally thought to be rare, has been reported in a considerable number of cases. Heightened awareness and clinical suspicion of the disease and a multidisciplinary approach are recommended to achieve a prompt diagnosis and optimize patient outcomes. Currently, there are no comparative studies to provide recommendations regarding optimal diagnostic methods, treatment options, and outcomes for endometriosis involving extrapelvic sites.