An unusual presentation of "silent" disseminated pancreatic neuroendocrine tumor.

To present a patient diagnosed with pancreatic carcinoid that was extremely rare and produced an atypical carcinoid syndrome. We reported a 58-year old male patient who presented with long standing, prominent cervical lymphadenopathy and occasional watery diarrhea. Pathohistological and immunohistochemical examination of lymph node biopsy showed a metastatic neuroendocrine tumor, which was histological type A of carcinoid (EMA+, cytokeratin+, CEA-, NSE+, chromogranin A+, synaptophysin+, insulin-). Bone marrow biopsy showed identical findings. Primary site of the tumor was pancreas and diagnosis was made according to cytological and immunocytochemical analysis of the tumor cells obtained with aspiration biopsy of pancreatic mass (12 mm in diameter) under endoscopic ultrasound guidance. However, serotonin levels in blood and urine samples were normal. It is difficulty to establish the precise diagnosis of a "functionally inactive" pancreatic carcinoid and aspiration biopsy of pancreatic tumor under endoscopic ultrasound guidance can be used as a new potent diagnostic tool.