A Rare Benign Pancreatic Lesion Mimicking Malignancy- Eosinophilic Pancreatitis

Background: Eosinophilic infi ltration of the pancreas is usually associated with generalized diseases like “sclerosing pancreatitis”, “eosinophylic gastroenteritis” and “systemic mastocytosis”. Most patients have systemic fi ndings such as eosinophilia, elevated IgE levels and gastrointestinal tract infi ltration Isolated eosinophilic infi ltration of the pancreas is much less common and is usually found in the histological evaluation of pancreatic specimens resected with the misdiagnosis of pancreatic cancer. Methods: Herein we report a rare benign pancreatic tumor that was operated on with the misdiagnosis of malignancy. Results: A 47-year-old woman underwent laparotomy with the diagnosis of cholestasis and suspected stone image in the common bile duct. No stone was found in the biliary tract; however, a pancreatic head mass was discovered. It was considered unresectable. Cholecystectomy and T-tube drainage was performed. The operative biopsy was non-diagnostic and the patient was referred to our clinic. Radiologic fi ndings revealed a resectable pancreatic head mass. A standard pancreatoduodenectomy was performed. The postoperative period was uneventful. Tissue diagnosis was “eosinophilic pancreatitis”, without stomach, duodenum, and proximal jejunum involvement. No infl ammation was detected on postoperative colonoscopy. Conclusion: Rare infl ammatory pancreatic diseases such as eosinophilic pancreatitis mimics malignancy. If a defi nitive diagnosis can be achieved before operative decision, the disease can be treated nonsurgically. Case Report A Rare Benign Pancreatic Lesion Mimicking MalignancyEosinophilic Pancreatitis Kurşat Rahmi Serin1, Muharrem Oner1, Nadir Adnan Hacım1* and Ali Emre2 1Bosphorus Clinical Science Academy, Beşiktaş, Istanbul, Turkey 2VKV American Hospital Nişantaşı, Istanbul, Turkey Received: 26 June, 2018 Accepted: 04 July, 2018 Published: 05 July, 2018 *Corresponding author: Nadir Adnan Hacım, Bosphorus Clinical Science Academy, Beşiktaş, Istanbul, Turkey, E-mail: adnanhcm@hotmail.com


Introduction
Eosinophilic infi ltration of the pancreas is an uncommon fi nding. Most patients with eosinophilic infi ltration of the pancreas have systemic manifestations such as eosinophilic infi ltration in other parts of the gastrointestinal tract.
Isolated eosinophilic infi ltration of the pancreas is a rare entity consisting of less than 1% of resected pancreatic specimens [1]. Herein we report a case of eosinophilic pancreatitis diagnosed after resection while it was previously thought to be malignant mass in the head of the pancreas.

Case Report
A 47-year-old woman was admitted to a state hospital with the complaints of jaundice, high fever and pain in the right upper abdomen. Abdominal ultrasonography revealed a dilated common bile duct and hydropic gall bladder without stone. However, a suspicious image of a calculus in the distal part of the common bile duct was encountered in the magnetic resonance cholangiopancreatography (MRCP). As endoscopic retrograde cholangiopancreatography (ERCP) was not available, an operative intervention was undertaken.
During the surgery, a fi brotic-hard and unresectable mass (The appearance was thought to be a vascular invasion) was palpated at the head of the pancreas. An incisional biopsy was taken; cholecystectomy and T-tube drainage were performed.
Biopsy showed a nonspecifi c infl ammation and the patient was For the following nine months, the patient didn't experience any recurrent attacks of pancreatitis.

Discussion
Eosinophilic pancreatitis (EP) is a rare condition that usually presents with obstructive jaundice and it is most often diagnosed in the histopathological examination of the specimen after pancreatic resection for suspicion of malignancy [2][3][4][5]. EP may occur as a component of hypereosinophilic syndrome with eosinophilic infi ltration of the gastrointestinal tract [4][5][6]. An allergic origin has been suggested in these cases [8,9]. Solitary eosinophilic infi ltration of the pancreas is a very rare event. In this patient, the operative indication was a mass in the head of the pancreas causing biliary tract obstruction. Although an incisional biopsy taken at another hospital had shown no signs of malignancy. We concluded that a tumor obstructing the distal common bile duct couldn't be ruled out. So, the true behavior was pancreatoduodenectomy. Histopathological examination displayed eosinophilic pancreatitis. There was no peripheral eosinophilia, nor eosinophilic infi ltration in other resected organs. Since there is no pathognomonic radiological method to diagnose EP, a defi nitive diagnosis in preoperative period is diffi cult. In this case, young age of the patient and absence of weight loss were not features of a ductal adenocarcinoma of the pancreas. However, resection was justifi ed, as it was not possible to rule out malignancy.
Misdiagnosed benign pancreatic tumor resection incidence is reported to be around 5% [10,11]. By the use of recent diagnostic modalities such as MR pancreatography, endoscopic ultrasonography and biopsy under its guidance, could avoid unnecessary surgical procedures. However, routine use of EUSguided biopsy for resectable pancreatic masses is controversial and American Gastroenterological Association recommends it only in unrespectable lesions [12]. Perhaps biopsy indications may be expanded in cases suspicious for benign tumors such as eosinophilic pancreatitis. Isolated eosinophilic infi ltration of the pancreas is less than supposed and the other gastrointestinal organs must be detected for the involvement [3,5]. If a defi nitive diagnosis can be achieved before operative decision, the disease can be treated non-surgically. Bastid et al. reported a case treated successfully by sodium cromoglycate and another by prednisolone [9].