[Pulmonary epithelioid hemangioendothelioma: a clinicopathologic analysis of six cases].

Abstract To investigate the clinicopathologic characteristics, differential diagnosis and prognosis of pulmonary epithelioid hemangioendotheliomas (PEHs). The clinical symptoms and imaging findings of 6 cases of PEHs were investigated and pathologic analyses including histomorphologic and immunohistochemical studies were performed. Clinical symptoms of the patients were nonspecific and insidious. The typical radiological manifestation was characterized by multiple small pulmonary nodules. The pathological findings were well-demarcated hypocellular hyalinized nodules with more cellularity at the periphery of the nodule. The neoplastic cells showed mild nuclear atypia and prominent eosinophilic cytoplasm with vacuoles, attempting to form primitive vasculature. Immunohistochemically, tumor cells were positive to CD31, CD34 and ERG. Follow-up data from 8 months to 5 years showed no tumor progression, except for the development of bone metastases in one case at 6 months. PEHs are uncommon vascular tumors with low-intermediate malignancy. Using H&E and immunohistochemistry, the final pathological diagnosis can be made and misdiagnosed as a benign fibrotic nodule or other malignant tumors can be avoided. The most effective treatment is surgical resection, if necessary, combined with chemotherapy or radiotherapy.