Ulcerated colorectal villous adenomas: A strong predictor of underlying malignancy

Abstract

Introduction: Colorectal villous adenoma (VA) is the least common of all histological types of colorectal polyps, but it has the highest malignant potential. Adenoma–carcinoma sequence follows a clinically predictable indolent course, and hence, there is scope for targeted clinical intervention. This study aimed to determine the incidence of malignant transformation of colorectal VA and correlate it with clinicopathological features. Materials and Methods: Ninety-eight cases of VA lesions retrieved from files of the Department of Surgical Gastroenterology at Amrita Institute of Medical Sciences, India, covering a 14-year period, were submitted to statistical analysis through the Chi-square test. Results: The mean age at presentation of VA with associated invasive malignancy was 59.5 ± 12.21 years, whereas of VA without malignant transformation, it was 66 ± 11.21 years. Males were more commonly affected than females (1.5:1). Rectum was most commonly involved. 56.1% of VAs were associated with invasive malignancy. There were 45.5% of VAs with low-grade dysplasia and 54.5% of VAs with high-grade dysplasia. Malignancy could not be ascertained in 43.1% of colonoscopic biopsies but established on surgical resection specimens. Conclusion: We infer that colorectal VA in Indian population has a higher risk of malignant transformation compared to the West. Colonoscopic biopsy grading of dysplasia may be limited on superficial biopsies, and therefore, pathological diagnosis with clinical and radiological correlation is important in taking management decisions. Ulcerated colorectal VA at index colonoscopy is a strong predictor of invasive malignancy. The authors recommend that there should be a high degree of suspicion for invasive malignancy in management of VAs.