ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 the overlapping immunohistochemical and morphology. The demonstration of EWSR1 gene rearrangement is the key for the definite diagnosis. E-PS-06-071 Colonic diaphragm disease as a rare cause of large bowel stenosis F. Rosa*, J. Lemos Garcia, J. Maciel, F. Cabral, F. Silva Brito, I. Rosa, I. Claro, R. Fonseca *Instituto Português de Oncologia de Lisboa Francisco Gentil, Portugal Background & objectives: The leading cause of large bowel obstructions in adults is a stricture secondary to malignancy. Colonic diaphragm disease (CDD) is a rare aetiology of stenosis, occurring mostly in the ascending colon of older women on long-term non- steroidal anti-inflammatory drugs (NSAIDs). Methods: We present a classic case of CDD with radiology, endo- scopic and pathological correlation. Results: A 74-year-old woman with a monoclonal B lympho- cytosis presented at an emergency department with a severe postprandial abdominal pain. The CT-scan showed an ascending colon circumferential stenosis and the colonoscopy showed an irregular and friable lesion, which was biopsied and consistent with an ulcer edge. Our multidisciplinary team proposed a right colectomy due to subacute intestinal obstruction symptoms. Examination of the specimen confirmed a single diaphragm- like stricture, conditioning a 70% lumen stenosis, with signs of proximal dilatation. Microscopic examination showed a plica with submucosal fibrosis compatible with CDD. The patient had multiple NSAIDs prescriptions. Conclusion: CDD is a rare condition associated with a common use drug. This case illustrates a typical case of a concentric stenotic lesion in the ascending colon presenting in an older woman medicated with NSAIDs. CDD is an important differential diagnosis of a colorectal neoplasm that pathologist and clinicians must be aware of. E-PS-06-072 Esophageal schwannoma: a rare case report A. Stofas*, A. Patereli, D. Goutas, H. Gakiopoulou, P. Korkolopoulou *1st Department of Pathology, School of Medicine, National and Kapodistrian University of Athens, Greece Background & objectives: Esophageal schwannomas are extremely rare, comprising ~2% of esophageal tumours and affect more frequently women between the 4th-6th decade of life. They are most often located in the proximal oesophagus. They are usually asymptomatic but some- times can cause dysphagia. Methods: We present a 47-year-old female who was referred for dysphagia with a history of an operation for diaphragmatic hernia and stenosis 20 years ago. Results: Biopsies from the lower oesophagus were sent for histopatho- logical examination and revealed a mesenchymal neoplasm composed of spindle-shaped cells with a fascicular pattern of growth and show- ing palisading of the nuclei. Immunohistochemically, the cells stained positive for S-100 protein and SOX10 but were negative for CD117, CD34 and Melan A. The mitotic index was low (1%). Conclusion: The prognosis for schwannoma is good since schwannoma is most often a benign tumour with a very low recurrence potential. Malignant transformation is exceptionally rare. The therapeutic management of esophageal schwannoma depends on several factors, such as clinical complaints, tumour size and pathological data (malignancy, mitotic index). Thus, most of the studies recommend surgical resection as treatment of choice. E-PS-06-073 Clinical and morphological approach in developing a decision support system for patients with autoimmune gastritis S. Mozgovoi*, A. Gubanova, M. Stepanchenko, M. Livzan *Omsk State Medical University, Russia Background & objectives: Autoimmune gastritis associated with a high risk of gastric atrophy, stomach cancer and neuroendocrine tumours. Development of a decision support system would be helpful to determine the diagnosis and observation of patients for timely detec- tion of gastric precancerous changes. Methods: In pilot cross-sectional comparative study, 60 patients (30 patients with autoimmune gastritis and 30 - H.pylori-associated ) were examined to identify informative diagnostic stimuli. General clinical investigation, upper endoscopy with OLGA-based staging of gastritis, IHC for neuroendocrine cells, antibodies to parietal cells and von Castle intrinsic factor, cyanocobalamin, ferritin, iron and folic acid levels were assessed. Results: Pathognomonical clinical findings of autoimmune gas- tritis patients were comorbidity with other autoimmune diseases (25 patients in the main group), cyanocobalamin deficiency (17 patients) and iron deficiency (13 patients). Endoscopy findings identified an endoscopic atrophic grade cutoff point of O3 on the Kimura–Takemoto classification (area under the curve [AUC]: 0,84). All patients in the core group were predominantly afflicted fundic glands and detection of extensive intestinal and/or pseu- dopyloric metaplasia/SPEM. The most common finding was a combination of intestinal metaplasia I and II types (AUC:0,86). All patients were reported linear and/or micronodular neuroendo- crine cell hyperplasia (AUC:0,92). Microcarcinoids was found in 5 patients, 4 had at least 1 neuroendocrine tumour. Conclusion: Based on the priority obtained, the initial diagnostic approach may be based on primary selection of a cohort of individuals with suspicion on autoimmune gastritis with an additional assessment of presence of autoantibodies to parietal cells and Castle’s factor, with the subsequent upper endoscopy in NBI mode and investigation of all the focuses of neuroendocrine hyperplasia. More research is needed to develop a mathematical model for medical decision support system. E-PS-06-074 Intestinal neuroendocrine tumours: prognostic particularities S. Elfekih*, F. Khanchel, I. Helal, H. Zaafouri, R. Hedhli, E. Ben Brahim, R. Jouini, A. Chadli *Habib Thameur Hospital, Tunisia Background & objectives: Neuroendocrine tumours (NETs) account for 2% of all gastrointestinal system malignancies and are most com- monly observed the small bowel followed by the rectum and the appen- dix. This study aimed to investigate the pathologic characteristics and prognostic factors of intestinal NETs. Methods: It is a retrospective study collecting all cases of intestinal NETs over a twenty-year period between April 2002 and January 2022 diagnosed in the pathology department of Habib Thameur Hospital, Tunis. All histopathological reports and clinical data were reviewed. Results: There were 35 intestinal NETs. Thirty (86%) were in the appendix, three (9%) in the small intestine and two in the rectum (5%). The mean age was 40,8 years. The mean tumour size was 10.3 mm [2-40 mm]. The tumour grade was G1 in 27 cases, G2 in S236