Primary neuroendocrine carcinoma of the thymus.

Primary neuroendocrine tumors of the thymus, previously known as carcinoid tumors of the thymus, are unusual and rare tumors, and prognosis for these patients has been difficult to predict. We hereby report a case of primary neuroendocrine tumor of the thymus that had an aggressive and fatal course in spite of surgical resection and adjuvant chemotherapy. These tumors must be regarded as a malignant neoplasm that is prone to metastasize to distant sites, even after total excision.