PTGS2 and invasive carcinoma: In Nigeria, the proportion of colorectal polyps that are adenomatous ranges from 28.8% to 47.5%.1,2,3,4,5 The distinct parameters that make adenoma relevant clinically include being a precursor lesion, harbouring invasive carcinoma, long latency period of malignant transformation, having similar clinical features with colorectal cancer (CRC), and as part of hereditary CRC syndrome.6,7,8,9 Emerging evidence implicates the role of the cyclooxygenase-2 (COX-2) enzyme in adenoma.