Pedunculated serrated polyp with histologic features of sessile serrated adenoma: a clinicopathologic and molecular study.

In this study, we describe a previously undescribed pedunculated serrated polyp of the colon showing typical features of sessile serrated adenoma/polyp (SSA/P). All polyps were pedunculated, located in the proximal colon, small in size, and occurred in elderly patients. Histologically, the polyps showed typical features of SSA/P in the basal crypts with irregular, asymmetric expression of Ki-67.