Thymic neuroendocrine tumor (thymic carcinoid): a clinicopathologic study in 15 patients

Abstract

Background: Thymic neuroendocrine tumor (carcinoid tumor) is rare, and prognosis for patients with this tumor has been difficult to predict.

Methods: The medical records of 15 patients were reviewed, and the patients were classified according to tentative TNM classification and histologic grade.

Results: Ten (66.7%) of 15 patients were male. Lymph node metastases were identified in 9 (60%) of 15 patients at the time of resection. There were one grade 1, nine grade 2, and five grade 3 tumors. Total resection was possible in 13 patients. Distant metastases developed in 10 (76.9%) of these 13 patients, although no local recurrence developed. Of these 10 patients, 6 died of distant metastases 5 to 25 months after the recurrence. Three patients are still alive, with metastases to the bone, spleen, and pleura 1 to 24 months after the diagnosis of recurrence. Two patients are presently tumor free (T1N0, grade 3 and T3N2, grade 2), but only 1 has survived beyond 5 years.

Conclusions: Thymic neuroendocrine tumor must be regarded as a malignant neoplasm that is prone to metastasize to mediastinal lymph nodes and to distant sites, even after total excision. Neither T and N classification nor histologic grade has been successful in predicting the outcome of a patient with this tumor. More aggressive management, including adjuvant therapies and reexcision of subsequent tumors, may result in increased survival.