A Case of Mixed Neuroendocrine-non-neuroendocrine Neoplasm of the Bile Duct with Spinal Paralysis due to Thoracic Vertebra Metastasis of the Neuroendocrine Carcinoma Components

Abstract

The patient was a 65-year-old male. We performed subtotal stomach-preserving pancreaticoduodenectomy for distal bile duct cancer. The pathological diagnosis revealed adenocarcinoma and a poorly differentiated tumor with spindle-shaped cell clusters and small rosette structures. Immunohistochemical examination revealed that the neuroendocrine tumor markers (chromogranin, synaptophysin, CD56, and SSTR2) were positive. More than 30% adenocarcinomas and neuroendocrine neoplasia (NEN) components were detected. Consequently, the patient was diagnosed with mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN). The patient was administered S-1 as postoperative adjuvant chemotherapy. Nine months postoperatively, the patient suddenly developed lower-limb paralysis. The thoracic vertebral metastasis compressed the spinal cord. The paralytic symptoms improved with thoracic posterior decompression with instrumented fusion. Bone tumor tissue obtained during the operation revealed neuroendocrine carcinoma (NEC). We diagnosed the patient with thoracic vertebral metastasis of the NEN component of the common bile duct (MiNEN). Subsequently, multiple liver metastases with severe thrombocytopenia were observed. The patient died approximately 11 months after the initial surgery. The findings contribute to our current understanding of MiNEN. In this rare case, the bone metastatic tissue was confirmed to be NEC component from MiNEN.