[Clinicopathologic and immunohistochemical study of pulmonary epithelioid hemangioendothelioma].

Objective: To study the clinical and pathological characteristics of pulmonary epithelioid hemangioendothelioma.
Methods: Four cases of pulmonary epithelioid hemangioendothelioma were studied by histopathologic and immunohistochemical examination of lung biopsy specimens.
Results: There were 3 female and 1 male, age 28 to 40 years. Clinically the tumor presented as multiple bilateral small nodules in the lung. Histologically, crown-like clusters of epithelioid tumor cells were obtained which filled in the alveoli locating at the periphery of the tumor nodules, while the central part of the nodules contained myxoid to hyaline matrix. The overall architecture of the lung was still preserved. Additionally, intracytoplasmic vacuoles were seen in tumor cells within which red blood cells were sometimes identified. Tumor cells generally lacked pleomorphism, mitotic activity and necrosis. They were immunohistochemically positive for CD31 and CD34. AE1/AE3 staining was positive in some cases.
Conclusions: Pulmonary epithelioid hemangioendothelioma often occurs in a middle-aged woman and represents a distinct clinical pathological entity.