Pure alpha-fetoprotein-producing neuroendocrine carcinoma of the pancreas: a case report

BACKGROUND: Alpha-fetoprotein (AFP)-producing pancreatic neuroendocrine tumors (pNETs) are rare, and the few reported cases usually coexisted with other malignant components such as adenocarcinoma or hepatoid carcinoma. We present here the first case of pure AFP-producing pNET. CASE PRESENTATION: A 56-year-old male patient underwent resection of the pancreatic tail and body because of elevated serum AFP levels and pancreatic mass. Microscopy showed that the tumor tissue consisted of large and small solid nests of polygonal cells. The tumor cells were positive for chromogranin A, synaptophysin, CD99, cytokeratin 19, pan-cytokeratin and β-catenin, and also showed diffuse immunoreactivity for AFP and human chorionic gonadotrophin. The mitotic rate was nearly 30 per 10 high-power fields and the Ki-67 index was nearly 25%. The histopathologic findings supported the diagnosis of an AFP-producing pNET. Other malignant components were not found. Serum AFP levels decreased to near-normal after operation and gradually increased to >1000 ng/ml at 5 months post-surgery. Recurrence and hepatic metastases were revealed by computed tomography. The patient died 21 months after surgery. CONCLUSION: This was the first case of pure AFP-producing pNET to be reported in the English literature. Serum AFP levels may provide useful information for monitoring the therapeutic effectiveness, early recurrence or metastases.