Mixed acinar-endocrine carcinoma of the pancreas--a case report.

INTRODUCTION Pancreatic tumors usually display either a ductal, an acinar or an endocrine differentiation. Mixed exocrine and endocrine pancreatic tumors are extremely rare. There have been a few reports of the rare entity of mixed acinar-endocrine carcinoma of the pancreas, where the endocrine cells represent more than 30% of the tumor. We herein describe a case of such a pancreatic tumor in an asymptomatic patient. CASE PRESENTATION A 74-year-old male patient with no evident clinical symptoms was referred for surgical resection of a large mass located on the pancreatic head, which was confirmed by an abdominal U/S, CT and MRI. FNA of the mass under endoscopic ultrasound guidance showed the cytology specimen to comprise of cells with morphological and immunohistochemical characteristics of endocrine pancreatic neoplasms. The patient underwent a modified Whipple's procedure and his post-operative course was uneventful. Pathological examination of the tumor revealed a mixed acinar-endocrine carcinoma of the pancreas. CONCLUSION Mixed tumors of the pancreas are extremely rare and their clinical features and pathogenesis remain unclear. The endocrine component seems to influence their prognosis favorably.Therefore, aggressive surgical therapy remains the only well established line of treatment for these tumors. Further accumulation of clinical cases will help clarify the clinical course and the optimal therapy for these unusual tumors.