Epithelioid hemangioendothelioma presenting as multiple pulmonary nodules following primary lung adenocarcinoma resection: a diagnostic challenge and clinical management dilemma

Abstract New pulmonary nodules after curative lung cancer surgery are usually presumed metastatic, yet rare second primaries can mimic this pattern and radically change management. Pulmonary epithelioid hemangioendothelioma (EHE) is an ultra-rare vascular sarcoma that often presents as bilateral, small nodules radiologically indistinguishable from metastases. A 58-year-old never-smoker developed innumerable bilateral sub-centimeter nodules 9 months after thoracoscopic right middle lobectomy for pT1aN0 lung adenocarcinoma. Surgical biopsy of multiple nodules—performed alongside resection of a separate enlarging lesion—revealed EHE with lymphatic invasion. This case illustrates diagnostic challenges in post-surgical lung cancer surveillance and emphasizes the importance of tissue diagnosis when clinical presentation deviates from expected patterns. The coexistence of primary lung adenocarcinoma and pulmonary EHE is exceptionally rare. This case highlight on importance of maintaining a broad differential diagnosis for new pulmonary nodules in cancer survivors, particularly when radiological patterns are atypical. Histopathological confirmation remains essential for accurate diagnosis and optimal treatment planning.