Endoscopically Unresectable Paneth Cell (PC)–Containing Adenomas and the Risk of Developing Colorectal Neoplasia

Abstract

Abstract Objectives Whether the presence of Paneth cells (PCs) in colorectal adenomas indicates an increased risk of colorectal neoplasia or not is controversial. We examined the clinicopathologic features of PC-containing adenomas (PCAs) that were surgically removed, focusing on the risk of developing subsequent colorectal neoplasia on follow-up. Methods A retrospective cohort of 154 patients with endoscopically unresectable colorectal adenomas who underwent surgical removal was retrieved. Archived pathology slides were evaluated for the presence of PC, villous features, and high-grade dysplasia. Demographic and clinical data were obtained by reviewing electronic medical records. A minimum 12 months of follow-up was considered valid follow-up data. Fisher’s exact test and Student t test were performed when indicated (P < .05 was considered statistically significant). Results PCAs were identified in 84 out of 154 cases (54.5%), commonly in the proximal as compared to distal colorectum (60.7% vs 38.1%, P = .018). There was no significant difference in patient age (mean, 66.0 vs 63.8), gender (M:F, 42:42 vs 35:35), adenoma size (mean, 3.18 cm vs 2.78 cm), villous features (69.0% vs 68.6%), and high-grade dysplasia (44.0% vs 35.7%) between PCA and non-PCA groups. After the mean follow-up duration of 65.8 months (range 12-169), 11 out of 30 patients (36.7%) had recurrent colorectal neoplasia, including 2 adenocarcinomas in the PCA group, as compared to 8 out of 27 (29.6%) in non-PCA group with no adenocarcinoma (P > .05). No statistical difference in the risk of developing colorectal neoplasia was noted between proximal PCA (24%), distal PCA (33.3%), and non-PCA (29.6%) groups. Conclusion PCAs are more common in the proximal colon, consistent with normal anatomic distribution of PC in the colon. No association was observed between PCA and high-grade dysplasia or colorectal neoplasia risk in endoscopically unresectable adenomas. PCA location was not a significant marker for future adverse outcomes.