先天緑内障患者に発生したα-smoothmuscleactin陽性びまん性胸膜悪性中皮腫の1例

Abstract

An autopsy case of diffuse malignant mesothelioma, once diagnosed as leiomyosarcoma based on the immunohistochemical results of open pleural biopsy, is described. A 54-year-old blind man was admitted to our hospital complaining of left pleural effusion. Chest CT examination revealed a mass of anterior mediastinum and left pleura. CT-guided pleuro-mediastinal biopsy showed hyalinized fibrotic tissue with spindle cells. Open pleural biopsy performed in another hospital showed spindle cell tumor with hypercellularity and frequent mitosis. Immunohistochemically cytokeratin5/6 was negatlve, vlmentin was posltlve, and α-smooth muscle actin (α-SMA) was positive. Two months and a half after the biopsy the patient died. At autopsy the tumor was found to spread over the left pleura, making a hard nodule in the upper mediastinum and protruding from the anterior chest wall. Microscopically cellular element was dominant in the pleura and collagenous tissue was abundant in the mediastinum. Tumor cells were positive for broad spectrum keratin and vimentin, compatible with diffuse malignant mesothelioma. Discussion is added concerning histological diagnosis of this case, α-SMA expression of mesothelioma cells, and the relationship between congenital glaucoma and mesothelioma.