Lower Gastrointestinal Tract Endoscopic Biopsies: Correlation between endoscopic and histopathologic features and assessment of diagnostic accuracy of endoscopy at St. Paul’s Hospital Millennium Medical College

Abstract

Summary Background: Lower gastrointestinal endoscopic biopsies are frequently used for the diagnosis and management of various gastrointestinal diseases. They provide a minimally invasive means of obtaining tissue for histopathologic assessment, which is the gold standard for the diagnosis of gastrointestinal pathologies. In Ethiopia, there are only a few studies done on correlation between endoscopic and histopathologic features of colonoscopic biopsies as well as their diagnostic concordance. Objectives: To assess the correlation between endoscopic features and histopathologic results of Lower GI endoscopic biopsies and the diagnostic accuracy of endoscopy in the diagnosis of Lower GI diseases done at St. Paul’s Hospital Millennium Medical College (SPHMMC), Addis Ababa, from August 2018 to August 2023 G.C Method: Cross sectional study was conducted and all lower gastrointestinal endoscopic biopsy samples from August 2018 to August 2023 G.C were included. Data was collected from the anatomic pathology record file and endoscopy reports by using structured, self-prepared anonymous questionnaire. Data was entered and analysed using SPSS version 25.The sample size was calculated to be 384. Descriptive analysis was used for sociodemographic data and histologic spectrum. Correlation was analysed using Chi square Statistical test. Magnitude of association was calculated using Phi and Cramer V and graded as follows:- absolute values of r, 0–0.19 is regarded as very weak, 0.2–0.39 as weak, 0.40–0.59 as moderate, 0.6–0.79 as strong, and 0.8–1.0 as very strong correlation. Diagnostic concordance/accuracy was assessed using sensitivity, specificity, Negative predictive value and positive predictive value by taking histopathologic diagnosis as a gold standard diagnostic test. Results: In this study the most common histopathological diagnosis was adenocarcinoma (23%). The correlation between non-specific colitis and erythema as well as non- specific colitis and ulceration was statistically significant (p < 0.0001). IBD showed statistically significant correlation with erythema, edema and ulceration (p < 0.0001). But the correlation between IBD and abnormal vascular pattern was not statistically significant. A significant correlation was also found between mass and adenocarcinoma (p < 0.0001). Endoscopy was found to have a high diagnostic yield with diagnostic accuracy of 84.6% for inflammatory lesions, 89.9% for malignant lesions and 86.4 % for polyps. Conclusion: This study showed adenocarcinoma was the commonest diagnosis in lower GI endoscopic biopsies followed by non-specific chronic colitis, which was the most common non neoplastic lesion. Moreover, it highlighted the significant correlation between endoscopic features and histopathologic patterns. The study also showed endoscopy has a high diagnostic accuracy, sensitivity and specificity in diagnosing inflammatory, malignant and polypoid lesions. Keywords: Colonoscopy, biopsy, Correlation, Sensitivity and Specificity, Ethiopia