Abstract
A 63-year-old woman was admitted with a mediastinal tumor that was incidentally diagnosed after an examination for palpitation.
Ultrasonocardiography revealed a large mass in the mediastinum, and chest CT showed a solid tumor, more than 10 cm in diameter, in the middle mediastinum. Extirpation of the tumor was performed via a thoracoscopic procedure. Pathological examination revealed that the tumor was composed of spindle cells with bizarre hyper chromatic nuclei and showed a high mitotic rate. A part of the tumor was connected to the esophagus wall.
Immunohistochemically, the tumor did not show differentiaton toward either smooth muscle or nerve, and these findings confirmed that the tumor was gastrointestinal stromal tumor (GIST), uncommitted type. The uncommitted type is regarded as malignant or potentially malignant, and rarely arises from the esophagus. It is necessary to consider this disease in the differential diagnosis of mediastinum tumor.
