[Aggressively metastatic neuroendocrine carcinoma in the middle mediastinum]

A 50-year-old male patient with no symptoms was admitted to our hospital for further evaluation of a right superior mediastinal mass shadow found in chest radiographs during a health examination. Computed tomographic (CT) scans demonstrated a middle mediastinal mass of 4 cm in diameter surrounded by the SVC, the ascending aorta and the trachea at the subaortic level. Routine examination disclosed no metastatic or primary lesion elsewhere. A surgical biopsy resulted in a diagnosis of neuroendocrine carcinoma of unknown primary organ. The patient was given 1 course of chemotherapy with CAV-PE, but little effect was seen. However, when a PE regimen combined with thoracic radiation was used, the tumor shrank to half of its size. After the patient subsequently received high-dose treatment with Etoposide, CT imaging and cytologic analysis revealed multiple metastases to the subcutaneous tissue, both adrenal glands and the liver. Lung lesions also spread aggressively, and the patient died of metastasis. Although neuroendocrine carcinomas can arise from the systemic neuroendocrine cells including those in the mediastinum, their appearance in the middle mediastinum is rarely reported.