Role of Colposcopy in Diagnosing and Differentiating Types of Cervical Intraepithelial Neoplasia

Abstract

Background: Preventing cervical cancer hinges on accurately detecting and treating high-grade cervical intraepithelial neoplasia (CIN2+) in individuals referred due to abnormal cervical cytology. While colposcopy has been a cornerstone in this process, concerns have arisen regarding its accuracy in CIN detection and differentiation. This study aims to assess the role of colposcopy in diagnosing and distinguishing various grades of CIN in clinically suspected patients. Methods: A descriptive cross-sectional study was conducted in the Department of Obstetrics & Gynaecology at Rajshahi Medical College Hospital, Rajshahi, over 12 months from February 2019 to February 2020. The study involved 110 women aged 20-70 years who presented with clinical symptoms indicative of precancerous cervical lesions. Initial evaluations included visual inspection with 5% acetic acid (VIA) and Reid colposcopy. Biopsy samples were collected from the identified lesions using the colposcope, and these samples underwent histopathological examination. The study compared the diagnostic accuracy of colposcopy, including sensitivity, specificity, positive predictive value, and negative predictive value. Results: Colposcopic evaluations revealed that 80% of the participants exhibited positive lesions (CIN), while 20% displayed negative lesions (normal cervix or cervicitis). Among the colposcopically positive lesions, 50% were graded as CIN-1, 29.5% as CIN-2, and 20.5% as CIN-3. Subsequent histopathological examination of the colposcopy-directed biopsies confirmed CIN or dysplasia in 44.5% of cases. Within this group, 36.7% had CIN-1, 34.7% had CIN-2, 12.2% had CIN-3, 10.2% had invasive squamous cell carcinoma, and 6.2% had carcinoma in situ. Colposcopy demonstrated a sensitivity of 83.7% in diagnosing CIN, with a specificity of 23%, resulting in an overall diagnostic accuracy of 55%. However, when differentiating high-grade CIN from low-grade lesions, colposcopy exhibited a high sensitivity of 92.3% and moderate specificity of 67.7%, with an overall diagnostic accuracy of 75%. Conclusion: This study concludes that colposcopy is highly sensitive in diagnosing CIN but has limited specificity in excluding patients with normal cervix or cervicitis. Nevertheless, it exhibits optimal sensitivity in differentiating CIN2+ and carcinoma in situ from low-grade lesions and maintains moderate specificity in excluding low-grade CIN. Colposcopy remains a valuable tool in preventing and managing cervical cancer, particularly in identifying high-risk lesions.