Brown slits for colorectal adenoma crypts on conventional magnifying endoscopy with narrow band imaging using the X1 system

Table 1 Characteristics of study subjects

Patient (n)	62
Age [mean ± SD (range), yr]	60.4 ± 12.8, (40-89)
Sex (male)	41.9%
Polyp (n)	108
Location (cecum/ascending/transverse/descending/sigmoid/rectum, n)	13/20/38/7/25/5
Morphology (0-Is/0-IIa, n)	13/95
Size [mean ± SD (range), mm]	7.45 (2.83, 5-15)
Brown slits (positive/negative, n)	57/51
Endoscopic diagnosis (adenoma/SSL/hyperplastic polyp, n)	59/30/19
Histopathological diagnosis (adenoma/SSL/MVHP/GCHP, n)	591/16/27/6
Endoscopist (1/2, n)	75/33
Endoscope (CF-HQ290Z/PCF-H290Z, n)	60/48

¹All adenomas were tubular, low grade.

SD: Standard deviation; SSL: Sessile serrated lesion; MVHP: Microvesicular hyperplastic polyp; GCHP: Goblet cell-rich hyperplastic polyp.

Table 2 Number of colorectal lesions for brown slits

	Adenoma1	SSL	MVHP	GCHP
Positive	56	0	1	0
Negative	3	16	26	6

¹All adenomas were tubular, low grade.

SSL: Sessile serrated lesion; MVHP: Microvesicular hyperplastic polyp; GCHP: Goblet cell-rich hyperplastic polyp.

Table 3 Diagnostic performance of brown slits for colorectal adenoma

Sensitivity	94.9 (85.9-98.9)
Specificity	98.0 (89.1-99.9)
Accuracy	96.3 (90.8-99.0)
Positive predictive value	98.2 (90.6-100)
Negative predictive value	94.1 (83.8-98.8)

Data are presented as percentage (95% confidence interval).