Thoracic Endometriosis Mimicking a Lung Mass: Management With Single‐Stage Biopsy and Microwave Ablation

Thoracic endometriosis syndrome is a rare extrapelvic manifestation involving the pleura, diaphragm or lung parenchyma. Presentation as a solitary pulmonary nodule mimicking malignancy is uncommon. We report a 31‐year‐old asymptomatic woman with an enlarging right lower lobe nodule, measuring 1.8–2.1 cm over 3 months. Following shared decision‐making, single‐stage image‐guided biopsy and microwave ablation ( MWA ) were performed. Histopathology confirmed pulmonary endometriosis. No clinically significant postoperative complications occurred, and the patient was discharged on postoperative Day 1. Follow‐up CT at 6 and 12 months demonstrated no obvious local recurrence without additional treatment. This case describes a potential minimally invasive approach for selected pulmonary lesions, although the safety, efficacy and long‐term outcomes of MWA for pulmonary endometriosis remain uncertain.