Malignancy in large colorectal lesions.

Context: The size of colorectal lesions, besides a risk factor for malignancy, is a predictor for deeper invasion objectives: To evaluate the malignancy of colorectal lesions ≥20 mm.

Methods: Between 2007 and 2011, 76 neoplasms ≥20 mm in 70 patients were analyzed.

Results: The mean age of the patients was 67.4 years, and 41 were women. Mean lesion size was 24.7 mm ± 6.2 mm (range: 20 to 50 mm). Half of the neoplasms were polypoid and the other half were non-polypoid. Forty-two (55.3%) lesions were located in the left colon, and 34 in the right colon. There was a high prevalence of III L (39.5%) and IV (53.9%) pit patterns. There were 72 adenomas and 4 adenocarcinomas. Malignancy was observed in 5.3% of the lesions. Thirty-three lesions presented advanced histology (adenomas with high-grade dysplasia or early adenocarcinoma), with no difference in morphology and site. Only one lesion (1.3%) invaded the submucosa. Lesions larger than 30 mm had advanced histology (P = 0.001). The primary treatment was endoscopic resection, and invasive carcinoma was referred to surgery. Recurrence rate was 10.6%.

Conclusions: Large colorectal neoplasms showed a low rate of malignancy. Endoscopic treatment is an effective therapy for these lesions.