Serrated colorectal lesions represent a challenge in colorectal neoplasia screening. Standard endoscopy features may among others include mucus capping, cloudy appearance and indistinct borders. For sessile serrated adenoma/polyp (SSA/P), more specific characteristics by magnification endoscopy were introduced by Japanese groups. In this classification, a (type II) open pit pattern as multiple dark spots is considered to be attributable to crypt dilation/enlargement by mucus accumulation. The potential utility of dedicated non-magnified endoscopy, more commonly applied in Western centers, in identification of this SSA/P presentation remains widely unexplored. However, here preliminary proof-of-principle evidence to this end is provided, albeit relying on ancillary adjunctives open for further systematic study.
In the first instance, an initially mucus-covered flat lesion had been identified with sufficiently demarcated borders on image-enhanced endoscopy (LCI mode, Fujinon) (Fig. 1A, after washing). Following acetic acid spraying, multiple punctate black spots putatively corresponding to open pits were visualized within the center (Fig. 1B). Final histopathology after cold snare endoscopic mucosal resection confirmed SSA/P without dysplasia. In another case of a right-colonic lesion with an exuberant mucus cloud (Fig. 1C), slow closure of a standard snare after washing and indigocarmin injection results in a presumed open pit pattern with non-dysplastic SSA/P demonstrated by final histopathology (Fig. 1D).
Example 1: (A) A mucus-covered flat lesion as identified with image-enhanced endoscopy using linked color imaging (LCI, Fujinon). (B) After acetic acid spraying, multiple punctate black spots corresponding to open pits became visible. Example 2: (C) A polypoid right-colonic lesion with an exuberant mucus cap. (D) After washing and submucosal indigocarmin injection slow closure of a standard snare resulted in a presumed accentuation of surface open pit pattern highly suggestive of sessile serrated adenoma/polyp (SSA/P).
The authors declare no conflict of interest.
