ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 *Dept. of Pathology, Tata Memorial Hospital, Mumbai, India Background & objectives: We aimed to grade and stage AMN, PMP cases diagnosed between January 2012- June 2019 using AJCC 8th edition and WHO 5thedition criteria; to see if the three- tier system has bearing on prognosis, survival and find individual adverse prognostic factors. Methods: After obtaining Institutional Review Board approval, slides of 81 patients (74 AMN and PMP; and 7 Goblet cell adeno- carcinoma (GCA)) were reviewed and their clinico-radiological details were obtained. For grading and staging, 3-tier system was used. Survival analysis was performed to determine outcome of patients in different AJCC grades and to find individual adverse prognostic factors. Results: For AMN and PMP, the median age was 56 years and median serum CEA was 14.45 ng/ml. There was a statistically significant difference in the Disease-free survival (DFS) of different grades and different histological entities of AMN (LAMN, HAMN, invasive adenocarcinoma, poorly differentiated mucinous adenocarcinomas) and PMP. Cytological atypia grade in appendix and pathological “M” stage showed statistically significant correlation with the DFS. The DFS of GCA was shorter than that of mucinous adenocarcinomas of appendix (G2 and G3). Tumour heterogeneity, scanty material on biopsy, inability to grade on cell block, discordance between biopsy and resection were some of the challenges faced during review. Conclusion: Grading AMN in three-tier system is feasible and has bearing on the prognosis. Grade of cytological atypia in appen- dix and pathological M stage were important variables affecting the prognosis. The prognosis of GCA is worse than mucinous adenocarcinomas. PS-07-032 Histopathology and surgery in early-onset inflammatory bowel disease: a Colombian-based cohort study R.D.P. Lopez-Panqueva*, D. Rubio-Cruz, J.F. Vera Chamorro, B. Mendoza de Molano, E. Londoño-Schimmer, R. García-Duperly, 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: Early-Onset Inflammatory Bowel Disease (IBD), both Crohn’s Disease (CD), and Ulcerative Colitis (UC) usually presents with greater severity and often need early surgical intervention. We aim to describe histopathological and surgical characteristics of IBD paediatric patients in a Colombian cohort. Methods: Longitudinal retrospective study including all patients ≤18 years who had an established diagnosis of IBD from 1977 to 2021, at Fundación Santa Fe de Bogotá. Patients were divided in two groups: patients with and without surgical intervention. A Kaplan-Meier curve was performed to estimate the cumulative risk of needing surgery overtime. Variables were analysed as measures of central tendency. Results: A total of 34 paediatric patients with IBD where found, 17 with CD and 17 with UC. 18 (58.8%) patients presented with severe disease activity confirmed by histopathology. Five (15%) patients developed low grade dysplasia, on average, after 6.7 years (σ: 2.5) and 20 (60%) required surgical intervention within the first 5 years, 75% with CD and 25% UC. Intestinal resection for fistula treatment, was performed in 50% of the cases, and 41.6% required surgical reintervention. A Kaplan Meier Curve estimated a cumula- tive risk, for the need of surgery, from the time of diagnosis of IBD with severe activity, of 15% at 1 year and 20% at 5 years. Conclusion: This study shows severe clinical and histopathologi- cal presentation of Early-Onset Inflammatory Bowel Disease in our cohort. Surgical intervention requirement was high among this population and tend to increase overtime. Although, as in the lit- erature, CD patients required more surgical procedures, need for surgery for UC was significant. A high percentage of reinterven- tions within the next years was also noted. Due to the severity of the disease, early suspicion, and diagnosis of paediatric or early- onset IBD could improve its natural course. PS-07-033 Expression of the ghrelin receptor in GIST I.A. Spiridon*, S.E. Giusca, D. Ciobanu-Apostol, I.D. Caruntu *U.M.F. "Grigore T. Popa" Iasi, Romania Background & objectives: Ghrelin is a hormone exerting complex metabolic functions through coupling with its receptor (GHSR). This axis has documented effects in obesity-related neoplasia, with scarce knowledge on gastrointestinal stromal tumour (GIST) tumo- rigenesis. We describe the expression pattern of GHSR in GISTs. Methods: The immunohistochemical (IHC) expression of GHSR was evaluated in 124 cases of GIST (78 gastric and 46 small bowel tumours) from adult patients, diagnosed based on histology and a standard panel of markers (CD117, CD34, DOG1). Statistical analysis was performed in order to correlate the tissue expression of the receptor with the classical clinicopathological factors. Results: The semi-qualitative expression of GHSR revealed dif- fusely granular, homogenous, cytoplasmic staining and nuclear immunoreactivity that showed differentiated staining, with het- erogenous intratumoral distribution in tumour core versus tumour periphery. An IHC score was developed to integrate these findings, differentiating between tumours with absent (score 0), low expres- sion (score 1) and high expression (score 2) of GHSR. The GHSR score correlated with the presence of myxoid degeneration of the stroma (p<0.001) and showed a statistically relevant association with patient prognosis, assessed through AFIP and m-NIH criteria (p<0.03). Significant correlations with other clinicopathological factors were not confirmed. Conclusion: Our results demonstrate that GISTs harbour spatial heterogeneity, with tumour cells in the periphery of the proliferation displaying a distinct phenotype when compared to the ones in tumour core. This feature could justify the differences in recurrence rates across tumours with various prognostic staging. The expression of GHSR in GIST is a potential indicator of the involvement of ghrelin axis in tumorigenesis, a promising result which can be further capitalized by molecular analysis of the isoforms GHSR1a and GHSR1b. PS-07-034 Evaluation of tumour-stroma ratio in gastric adenocarcinomas with semi-automatic digital imaging method and its relation with clinicopathological parameters and prognosis B.E. Gözükara*, A. Gönültaş, A. Sürmelioğlu, F. Aker, M. Doğan *Haydarpasa Numune Education and Research Hospital, Turkey Background & objectives: The importance of tumour-stroma ratio (TSR) as a prognostic marker in some cancer types has been demonstrated. The aim of this study is to examine the relation- ship between TSR and histopathological parameters and survival in gastric adenocarcinomas. Methods: The study group was formed with 155 cases of gas- tric resection specimens diagnosed with adenocarcinoma between 2011-2018. Stroma areas were calculated using semi-automatic digital imaging and software (EasyPath, Argenit, Turkey). The S99