Extrauterine Adenomyoma of the Lung: A Rare Case Report.

Background: Extrauterine adenomyomas (EAs) are rare benign lesions that arise outside the uterus and only rarely involve the lung. Case Presentation: We describe a 34-year-old woman with a history of multiple gynecological surgeries who was diagnosed with a pulmonary benign uterine adenomyoma. Chest CT, pelvic MRI, and ultrasound revealed pulmonary masses, uterine adenomyosis with fibroids, and an adnexal cystic mass. A CT-guided lung biopsy confirmed benign uterine adenomyoma; the diagnosis was supported by histopathological and immunohistochemical findings. The patient received goserelin acetate and letrozole, and serial follow-up chest CT through November 2024 showed stable pulmonary lesions without respiratory symptoms. Conclusion: This case highlights the importance of considering EAs in the differential diagnosis of pulmonary masses, particularly in individuals with uterine adenomyosis. It demonstrates that endocrine therapy can be an effective option for managing benign adenomyomas in patients who are inoperable or prefer non-surgical management.