Groove Pancreatitis Masquerading as Carcinoma Pancreas : A Diagnostic Dilemma

Abstract

INTRODUCTION: Groove pancreatitis(GP) is a rare special form of chronic pancreatitis localised to pancreaticoduodenal groove, presents commonly with signs and symptoms of duodenal obstruction, mimicks pancreatic cancer radiologically and the surgeon proceeds with inadvertent whipples procedure. PRESENTATION OFCASE: A28yr old gentleman, alcoholic presented with duodenal obstruction for 3days. CECTabdomen was suggestive of exophytic lesion from second part of duodenum ?duodenal diverticulum. UGIE showed large growth with overlying abnormal mucosa causing luminal compromise in second part of duodenum. Biopsy was taken which showed normal villous pattern. Patient was managed conservatively and improved gradually. On further evaluation, EUS showed 5×5.5cm cystic space occupying lesion in close relation to second part of duodenum and head of pancreas ?origin. EUS guided FNAC showed features suggestive of adenocarcinoma. With this pathological diagnosis, patient was taken up for Whipple's procedure, intraoperatively, 3cm mass lesion was noted in the pancreaticoduodenal groove. HPE of the specimen showed a haemorraghic nodule (3×1.8×1.2cm) in the duodenal wall and changes of chronic pancreatitis in the pancreticoduodenal groove suggestive of GP. Postoperative period and follow up of 6 months was uneventful. DISCUSSION: In GP, EUS guided FNAC may reveal large gaint cells, spindle cells or hyperplasia of brunner glands depending on the area of sampling and these features mimic neoplasia as observed in our case. MRI criteria given by Kalb et al show diagnostic accuracy of 87.2% for GP and negative predictive value of 92.9% to rule out pancreatic cancer. Arvanitakis et al showed stepwise management approach is effective in GP and with combination of medical and endoscopic treatment, complete clinical response rate was observed in 80%. CONCLUSION: It is important to diagnose and differentiate GP from pancreatic cancer preoperatively and avoid morbidity from unnecessary pancreaticoduodenectomy in patients of GP.