ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 analysis should be encouraged to better understand the underlying mechanisms by which they develop. E-PS-07-017 Audit of key pathological parameters in pancreaticoduodenec- tomy specimens performed for pancreatic ductal adenocarci- noma in a national centre over an 11-year period J. Maguire*, J. Yang, M.B. Cotter, J. Murphy, N. Swan *St Vincent’s University Hospital, Ireland Background & objectives: Pancreaticoduodenectomy(PD) is the mainstay of curative treatment for pancreatic ductal adenocarcinoma(PDAC), however, the approach to pathological exami- nation varies widely. Our aim was to assess the rate of microscopic margin involvement(R1) and nodal involvement(N1) in PD specimens performed at our institution. Methods: Pathology reports from PDs performed for PDAC were retrieved from our laboratory database between 2011-2021. Mar- gin status, number/name of involved margins, number of positive lymph nodes and the correlation between nodal positivity and R1 status were assessed. Patient age, sex, neoadjuvant treatment status, tumour grade and stage were also recorded. Results: A total of 272 PD specimens were received. The majority were in males(55%) and the median age was 69. 63% were grade 2. The median number of nodes retrieved was 18 with 67% showing N1 status. 35% of specimens had a final R1 status. Of these, 59% had a single involved margin, 41% had multiple involved margins. The facing superior mesenteric vein(SMV) dissection margin was the most commonly involved(51%). The pancreatic neck transection margin was involved in 15%. 29% of the cases had prior neoadju- vant treatment. The R1 rate in the neoadjuvant cases was 20%. 83% of R1 cases had metastatic disease to lymph nodes(N1). Conclusion: Using the Royal College of Pathologists criteria for positive margin status in PD specimens (<1mm to inked margin), the rate of R1 status in our cohort has averaged at 34% (11%- 64%) over 11 years. The margin most often involved was the facing SMV dissection margin. Neoadjuvant cases had a low rate of R1 status(20%). Margin involvement was associated with lymph node involvement in 83% of cases, in keeping with international data. E-PS-07-018 Intraductal oncocytic papillary neoplasm of the pancreas asso- ciated with invasive carcinoma: case report R.D.P. Lopez-Panqueva*, J. Andrade-Restrepo, A. Vera Torres, R.E. Andrade Perez *Department of Pathology and Laboratory Medicine Hospital Universitario Fundación Santa Fe de Bogotá/School of Medicine, Universidad de los Andes, Bogotá, Colombia Background & objectives: Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is an uncommon type of cystic pancreatic tumour. Additionally, although rarely reported, association with invasive carcinomas has been established but its long-term behaviour hasn’t been fully described. Methods: A 62-year-old was programmed for endoscopic ultra- sound after an incidental finding of a pancreatic cyst. The study revealed a multiloculated cyst with thick septs and a single solid nodule inside, suggestive of a mucinous neoplasm. The lesion was associated with asymmetric dilation of the principal pancreatic duct. Patient underwent pancreatoduodenectomy, and excised tis- sues were sent to pathology. Results: The excised tissue showed a multiloculated cyst with a 2 cm diameter. Histopathological study of the resection revealed an intraductal papillary growth from a pseudostratified epithelium of cuboidal cells with big nucleus, prominent nucleolus, and increased eosinophilic cytoplasm (oncocytic); associated with occasional goblet cells. They are arranged in focal, cribriform and cystic struc- tures, which morphologically correspond to IOPN. In addition, adjacent to the main cyst formation, foci of irregular glandular structures made up of oncocytic epithelium are found, surrounded by desmoplastic stroma, revealing an associated invasive carci- noma. HepPar-1 and CK-7 were positive in both the invasive and intraductal components, and Ki-67 was expressed in 30%, confer- ring a high proliferation rate. Conclusion: IOPN has been historically considered a subtype of intraductal papillary mucinous neoplasm (IPMN). Nonetheless, recognized recently as a distinct entity from IPMN, also determined as a precursor of invasive carcinoma. The association of background invasive carcinoma and its postresection surveillance have not been fully described, and ranges from 20-60%; occasionally associated with completion of pancreatoduodenectomy. Consequently, there’s a need to report cases, for further characterization and development of adequate protocols for long-term management E-PS-07-019 Correlation of endosonography-guided fine needle aspira- tion cytology, and needle biopsy in the diagnosis of pancreatic lesions, at Fundación Santa Fe de Bogota, Colombia R.D.P. Lopez-Panqueva*, H.A. Gonzalez, R. Pinto-Carta, A. Vera Torres, M. Mejía-Arango *Department of Pathology and Laboratory Medicine Hospital Universitario Fundación Santa Fe de Bogotá/School of Medicine, Universidad de los Andes, Bogotá, Colombia Background & objectives: Diagnosis of pancreatic lesion is challenging. Endosonography-guided aspiration (EUS ‐ FNA) and biopsy (EUS ‐ FNB) are useful as a diagnostic tool. This study aims to define the correlation between eco-endosonograpy-guided fine needle aspiration cytology, and through-the-needle biopsy diagnosis of pancreatic lesions. Methods: This is a cross-sectional study of patients who under- went EUS-FNB and EUS-FNA as part of the diagnosis of pan- creatic lesions. Diagnostic correlation for the two most common diagnosis: ductal adenocarcinoma (PDCA), and neuroendocrine tumour (pNET), with the two tests was evaluated using hypoth- esis test, correlation coefficient, and prevalence of diagnosis. Results: One hundred-seventeen patients were evaluated, 59(50.43%) male, and 58(49.57%) female. Seventy patients (70) were diagnosed with PDCA, and nineteen (19) patients with pNET. Other diagnoses included autoimmune pancreatitis, necrotizing granulomatous disease, and mucinous neoplasms among others. There was a good correlation between cytology and biopsy diagnosis for PDCA (chi2 P=0,0001), and (kappa-Cohen 0.7844; IC(0,5356-1,0332). Surgical specimens’ information was available for 17 patients. Diagnostic correlation of cytology and surgical specimen was (0.736; IC(0,3872-1,085)). A total of 41(58,57%) patients, presented with advanced, inoperable, PDCA. For 19 patients with pNET, no correlation between cytology and biopsy specimens was found (p=<0,21). All pNET tumours were small, under 2 cm in diameter. Conclusion: There is a correlation between cytology and biopsy diagnosis of PDCA, making both tests comparable. For pNET, no correlation was found, although the number of cases was limited, and most cases were small and challenging to access. S244