A 55-year-old man had unremarkable personal and family histories. Due to a positive fecal occult blood test, he underwent a video colonoscopy that identified multiple (more than 40) flat, elevated polyps (Paris classification 0-IIa) from 10 to 50mm in diameter, and predominating in the right colon (figs. 1 and 2). Magnification chromoendoscopy with acetic acid at 3% was performed (figs. 3 and 4), providing a better definition of the polyps. The anatomopathologic study of one of them reported serrated adenoma with no cytologic dysplasia (fig. 5).

Figure 1.

Endoscopic aspect of the serrated polyps. Flat polyp located in the appendicular orifice.

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Figure 2.

Serrated polyp located in the ascending colon. Vascular pattern loss is a characteristic unique sign of the presence of a serrated polyp.

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Figure 3.

Chromoendoscopy with the application of acetic acid facilitates the characterization of the lesion and the delineation of its boundaries.

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Figure 4.

High-resolution white light image and its magnification after performing chromoendoscopy with acetic acid. A glandular pattern characteristic of the II-O open serrated adenomas described by Kimura et al. is shown.

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Figure 5.

Serrated sessile adenoma with no dysplasia (hematoxylin/eosin). The basal luminal dilations (arrow) are characteristic of the glands in the shape of an “anchor”, “J”, or “boot” are shown. This architectural characteristic is objective and easy to identify and differentiates hyperplastic polyps from the microvesicular type.

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In accordance with the WHO definition, serrated polyposis syndrome (SPS) was diagnosed due to the presence of more than 20 serrated polyps of any size distributed throughout the colon.

Given the multiplicity of the large lesions that were predominant in the right colon and the topography of one of them at the level of the appendicular orifice, conditioning its endoscopic resectability, the joint decision among surgeons was made to perform a right hemicolectomy, as well as resection by mucosectomy of the polyps described in detail in the left colon.