To conduct a systematic review of the literature on patients with extrapelvic deep endometriosis. Data Sources: A thorough search of the PubMed/Medline, Embase, and Cochrane databases was performed. Methods of Study Selection: Studies in the last 20 years that reported on primary extrapelvic endometriosis were included (PROSPERO registration number CRD42019125370). Tabulation, Integration, and Results: 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. Conclusion: 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.
