Clear Cell Carcinoma of the Pancreas Infiltrating Duodenum: A Case Report of a Multiface Aspect of an Intriguing Entity

Abstract Background: Although Clear-cell carcinoma has been found in various organs as a variant of ductal carcinoma of the pancreas, it still hasn’t been well recognized. According to the WHO classification, primary Clear-cell carcinoma of the pancreas is rare, and it is classified as a “miscellaneous” carcinoma. To date it has been poorly characterized and only few cases have been reported in the literature [1]. Case presentation: We report here an unusual case of Clear-cell carcinoma in a 59-year-old man involving the head of the pancreas and the second part of the duodenum initially misconceived as pyloric gland adenoma, a rare duodenal entity. Nevertheless, duodenal sub stenosis was suspected of malignancy, so further investigations were made. Subsequent abdominal computed tomography (CT) detected not only a duodenal vegetation but also an alteration of the duodenal-pancreatic interface with thickening of the duodenal wall and a common bile duct dilatation. The malignant clinical aspect and behavior of the lesion, associated to the impossibility of further investigations due to the duodenal sub stenosis, led to an exploratory laparotomy.The laparotomy revealed a retracting area straddling the duodenum and the pancreatic head. A duodenum pancreatectomy of the head of the pancreas with extended lymphadenectomy was performed and the histological evaluation showed a ductal Clear-cell adenocarcinoma of the pancreas infiltrating the duodenum. The postoperative course was characterized by a pancreatic fistula grade B. At 6 months from the surgery, the patient hasn’t had recurrence.Conclusion: Because it is a rare tumor with very few cases reported previously, the incidence and prognosis are not well known for this neoplasm. The report of our case would aid in the identification of this rare neoplasm. Further studies and more case reports are needed to clarify the diagnosis and prognostic significance of the clear cell differentiation of these tumors.