Primary pulmonary epithelioid hemangioendothelioma.

Pulmonary epithelioid hemangioendothelioma (PEH) is a rare tumour of vascular origin with low to intermediate malignancy. Typical radiological finding on CT is multiple small nodules in bilateral lungs, and some will have punctate calcifications and pleural thickening. The diagnosis of PEH is confirmed by histopathological findings and positive immunohistochemistry staining. We report a case of a woman in her 50s with a medical history of lung adenocarcinoma. Later, regular chest CT during a routine cancer follow-up revealed multiple small pulmonary nodules and increased sizes of these nodules on serial images, initially misdiagnosed as multiple lung metastases. The histopathological diagnosis was made on a pulmonary wedge resection. Finally, PEH was diagnosed on the basis of positive immunohistochemical staining for CD31, ERF and TFE3. In the current study, the clinicopathological features and review of the literature were investigated. Our case highlights the importance of a histological diagnosis to avoid misdiagnosis.