[Carcinoid tumors of the thymus--a report of 7 cases]

Carcinoid tumor of the thymus is rare and often clinically misdiagnosed as thymoma. However, those two types of tumors differ from each other greatly in their origin, biological behavior, accompanying syndromes, pathological features as well as prognosis. Seven cases of this tumor are presented here, which have had surgical intervention and pathological confirmation. Two of them were accompanied with Cushing's syndrome, another one was associated with pericarditis. Resection was accomplished in 5 cases and exploratory thoracotomy in 2 cases. Among the 7 cases, the two cases receiving exploratory thoracotomy died of tumor in its late stage. One patient died of widespread bone metastases 2 years after resection. One had tumor recurrence 3 years after original tumor resection and received another surgical operation. The characteristic features of carcinoid tumors of the thymus are diagnostic difficulty, potential malignancy, frequent recurrence and extrathoracic metastasis for prolonged period postoperatively. Histopathological, electron microscopic and immunohistochemistry examinations may be required in making an accurate pathological diagnosis. Thorough surgical excision of the primary and secondary tumors is of great importance in treatment.