[Large cell neuroendocrine carcinoma of the mediastinum].

We describe a rare case of primary mediastinal large cell neuroendocrine carcinoma (LCNEC) with brain metastases. A 65-year-old man presented with a mediastinal abnormal shadow on chest radiography. A computed tomography-guided needle biopsy of the mediastinal tumor revealed malignant cells. After biopsy, dyspnea, leg weakness and a waddling gait rapidly developed. Magnetic resonance imaging of the brain revealed three masses with ring enhancements. His pro-GRP value was 95.5 pg/ml. Since the cerebellar tumor extended to the brain stem, it was removed surgically. The brain tumor demonstrated LCNEC. He received systemic chemotherapy of cisplatin and irinotecan, because his leg weakness and waddling gait had improved markedly after surgery followed by whole brain irradiation.