Portal de Periódicos da CAPES

What is type II-open pit pattern?

2016; Wiley; Volume: 28; Linguagem: Inglês

10.1111/den.12603

1443-1661

Hiro‐o Matsushita, Hiro‐o Yamano,

Mycobacterium research and diagnosis

On the basis of our translational research, we have reported that type II-open pit pattern should be the characteristic finding of magnifying endoscopy of sessile serrated adenoma/polyp (SSA/P).1 We present a case of SSA/P with the typical type II-open pit pattern. A slightly elevated lesion was detected in the ascending colon (Fig. 1). Color of the lesion was almost the same as that of the surrounding mucosa and some mucus was attached to the surface (Fig. 1a). Dark spots and dilated vessels were partially revealed by using narrow band imaging in magnified view (Fig. 1b). After indigocarmine dye spraying, wide-open, round-shaped pits with mucus inside were recognized, reflecting the dilatation and enlargement of the crypts. We judged the lesion as type II-open pit pattern with a diagnosis of SSA/P (Fig. 2). In our data, specificity of type II-open pit pattern for SSA/P was very high, approximately 98%. However, it is considered difficult to define type II-open pit pattern objectively. Accumulated mucus forms in the dilated crypts of type II-open pit pattern, and the degree of opening of the crypts depends on the amount of mucus. Shape, degree of opening, and number of type II-open pits change the shape by altering the amount of mucus, as does washing with water. We have also observed a change in the shape of the crypts with time. Considering this, there are problems not only in the endoscope diagnosis, but also in the pathological diagnosis of SSA/P. The general acceptable criteria of SSA/P have not been established; therefore, here we temporally use the term SSA/P according to the definition given by the Japanese Society for Cancer of the Colon and Rectum. In spite of these limitations, type-II open pit pattern can be considered as the characteristic colonoscopic indicator of SSA/P. Authors declare no conflicts of interest for this article.