A 68-year-old woman was admitted to our hospital with severe back pain. Laboratory data revealed high serum levels of LDH, CRP, and NSE (101 ng/ml) . The diagnosis of PDNEC was confirmed with a biopsy specimen from the lesion. Conventional cisplatin plus irinotecan chemotherapy was administered. Furthermore, radiation therapy was performed at the primary site and bone metastases, and radiofrequency ablation (RFA) was administered to hepatic metastases for down staging. Nevertheless, chemotherapy could only be continued for two courses because of the patient’s depression, and overall survival was ten months. This is a report describing a case of advanced PDNEC in which multidisciplinary treatment was performed.