Analysis of Whipple’s Resection Specimens: A Histopathological Perspective

Background: Pancreaticoduodenectomy or Whipples’s procedure is done for pancreatic carcinoma, bile duct carcinoma, duodenal carcinoma and periampullary carcinoma. About 5% of the gastrointestinal malignancy is constituted by the ampullary and periampullary carcinoma. Histopathological studies related to the diagnosis, grade, stage, nodal status, marginal status, prognosis and incidence of these tumors are analyzed from the received Whipple’s specimen in our study. Aim of this study is to analyze the incidence of various tumors we encounter in the Whipple’s specimen, to calculate the sex ratio, to grade and to stage the tumors based on the WHO grading system. And to compare the incidence with other studies. Methods: Histopathology records of all the patients who had Whipple’s resection during September 2013 September 2015 were analyzed. The slides were reviewed and the parameters were calculated. Results: Out of thirty cases, on which Whipple’s resection was done, twenty one had ampullary and periampullary carcinoma, The mean age incidence of ampullary carcinoma calculated was 44 years. The sex ratio of ampullary carcinoma was 1:1. Three had pancreatic tumors and six had chronic pancreatitis. Out of the three cases with pancreatic tumor, two had pancreatic endocrine tumors. They both were female. One had a Solid pseudopapillary pancreatic tumor. Literatures were reviewed and the predominance of ampullary carcinoma was noted in our study in contrast to other studies. Conclusion: In the analysis of the Whipple’s specimen we found out that ampullary adenocarcinoma predominates and there were an equal sex incidence. This is in contrast to other published literatures. This variable needs further evaluation. Original Article *Corresponding author: Dr.Shifa.S. 82,J.N.Nagar, Old Natham Road, Madurai625017 TamilNadu, India. Phone: +91 9486669274 Email: [email protected] A-106 Whipple’s Resection Specimens Annals of Pathology and Laboratory Medicine, Vol. 03, No. 02, April June 2016 Introduction Pancreatoduodenectomy otherwise called Whipple’s surgery was first demonstrated by Allen. O Whipple in 1935.[1] This procedure is done for periampullary carcinoma, ampullary carcinoma, pancreatic tumors, tumors of the pancreatic duct, tumors of the common bile duct, duodenal carcinoma and sometimes for nonmalignant conditions. [2] 80% of the tumors in this region are adenocarcinoma and other malignancies form the rest. Ampullary carcinoma has the histological features of duodenal mucosa and the ducts. Tumors in this region are mostly seen among elderly age group around seventh decade and surgery is the only means of curing them. Because of the intimate location of many structures in this area even a benign lesion can cause obstructive symptoms. [2] Whipple’s surgery had been done on those benign conditions as they mimick malignancy. Histopathology is the gold standard when such situation arises. This study was done to analyze these Whipple’s specimens histopathologically by retrieving the old records and slides and critically analyze and sort them according to the site, size, type, and grade, nodal and marginal status. Along with that, the age and sex incidence was analyzed. The prognostic significance of all these characters was analyzed to get the overall picture of these cases in our hospital setup. Comparison of the incidence of our hospital with other literatures was also attempted. Materials and Methods This is a retrospective study of the cases done during September 2013September 2014. All the cases on which Whipple’s surgery was done for both the malignant and nonmalignant reasons were retrieved from the old records. The details about the gross examination of the specimen were taken from the records. Protocols used in the gross examination: ● When most part of the tumor is located in the ampullary region and bulges into the duodenal mucosa stretching it, it is taken as ampullary carcinoma. Adsay V et al in their study had mentioned that they designate ampullary carcinoma if more than 75% of the tumor was seen in the ampullary region.[3] ● A tumor that involved the circumference of the ampulla was taken as periampullary carcinoma. ● A tumor that involved the circumference of the common bile duct [CBD] was taken as common bile tumors. Longitudinal thickening of the bile duct and granular mucosal surface were taken as clues. Gonzalez RS et al in their study had mentioned that common bile duct tumor constitutes 5% among the tumors of pancreatoduodenal origin. [4] The incidence of CBD tumor is higher among Asians.[3] ● A tumor with the base or the epicenter in the duodenum and not involving the ampulla was taken as duodenal carcinoma. Non ampullary duodenal carcinoma is different from its duodenal counterpart and the plaque like growth of the non ampullary carcinoma is associated with microsatellite instability. [5] ● Other gross features like cystic neoplasms of the duct, spongy areas in serous cystadenoma of the pancrea were noted. ● Tumor size, color, consistency, gross invasion and measurements were noted. ● NodesNumber and size were noted. ● Homogenous white gross appearance was taken as a clue for pseudo tumors. Most of the benign lesion occurs around the pancreatic head and the periampullary region. They cause obstructive symptoms mimicking carcinoma leading on to Whipple’s surgery.[2] The slides were reassessed. Histopathological categorization, grading, tumor budding, staging, nodal status, perineural invasion, angioinvasion and marginal status were assessed. The grading of adenocarcinoma was done based the percentage of glands seen in the tumor tissue. If there were >95% glands it was taken as well differentiated, 5095% glands as moderately differentiated grade, 5-49% as poorly differentiated grade and ,5% as undifferentiated adenocarcinoma. The staging of the Ampullary carcinoma was based on AJCC TNM classification.T1 – If the tumor is limited to the ampulla or sphincter of Oddi. T2If the tumor invades the duodenal wall.T3If the tumor invades the pancreas and T4If the tumor invades the peripancreatic soft tissue or adjacent structures.N1If there is regional nodal metastasis. In the case of Endocrine neoplasm, the following staging was followed. T1If the tumor is limited to the pancreas and it is less than 2cm in diameter. T2 -If the tumor is restricted to the pancreas and size is between 2-4 cm. T3 If the tumor is more than 4 cm diameter if it is limited to the pancreas or if the tumor invades the duodenum or the bile duct. T4If the tumor invades the adjacent organs. N1If the regional nodes are involved by the tumor. In case of the solid pseudo papillary tumor T1When the tumor is limited to the pancreas and was less than 2cm in diameter.T2When the tumor is limited to the pancreas and more than 2cm in diameter. T3When the tumor invades duodenal, peripancreatic tissue and the bile duct. T4When the tumor invades the other structures. Ibrahim et al. A-107 www.pacificejournals.com/apalm eISSN: 2349-6983; pISSN: 2394-6466 N1aWhen a single node is involved. N1bMultiple regional nodes were involved. Result Thirty Whipple’s specimen was received during our study period. Out of that, twenty one had ampullary carcinoma and periampullary carcinoma. It constitutes around 70% of the tumors in our study. When the age incidence of ampullary carcinoma was calculated the mean age of occurrence in our study was 44 years [Table 1]. The youngest case in our study was a 35 year old female. Neither familial clustering nor familial syndromes were seen in our study. When the sex ratio was analyzed among the patients with ampullary carcinoma, the male to female ratio in our study group was almost 1:1 [Table 1]. The mean size of the ampullary tumor in our study was 2.4cm [Table 2]. In 89.5% of the cases of the ampullary carcinoma was of intestinal type [Fig1] and 10.5% of the cases were of pancreatobilliary type [Fig 2]. Among them, 38% of the cases were well differentiated grade and 62% were moderately differentiated grade. Poorly differentiated grade was not observed in our study [Table 3]. In our study, 68% were in stage two [Table4]. Only 10% of the cases showed metastatic deposits in the nodes and 10% of the ampullary carcinoma showed angioinvasion [Fig 3] [Table 5]. Margins were free of tumor invasion in all the cases. Pancreatic endocrine tumor was the second commonest tumor we encountered while analyzing the Whipple’s specimen. In our study, both the cases with the pancreatic endocrine tumor were females [Fig 4]. They were 40 and 42 years old with the mean age of 41 years. Both the tumor was more than 2cm and they were in stage T2 [Table 2]. Both were nonfunctional and showed angioinvasion and neural invasion [Fig 5] Whipple’s surgery done in six cases presumed of malignancy was diagnosed as chronic pancreatitis in our study. Table 2: Tumor size distribution in the Whipple’s specimen Tumors 1-2cm 2.1-3cm 3.1-4cm >4.1cm Ampullary carcinoma 9 7 2 1 Periampullary carcinoma 1 1 Pancreatic Endocrine Tumor 1 1 Solid Pseudo Papillary tumor 1 Table 3: The distribution of type and different grades among the ampullary carcinoma Type Well Differentiated grade Moderately differentiated grade Poorly differentiated grade