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

## TL;DR

A rare case of a vascular tumor called epithelioid hemangioendothelioma (EHE) was diagnosed in a lung cancer survivor, highlighting the need for careful diagnosis when new lung nodules appear.

## Contribution

This case emphasizes the diagnostic challenge of distinguishing rare tumors from metastases in cancer survivors.

## Key findings

- A patient developed bilateral pulmonary nodules after lung cancer surgery, which were later diagnosed as EHE.
- The coexistence of primary lung adenocarcinoma and pulmonary EHE is exceptionally rare.
- Tissue biopsy confirmed the diagnosis, underscoring the importance of histopathological confirmation in atypical cases.

## 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.