Is endoscopic ultrasonography essential for endoscopic resection of small rectal neuroendocrine tumors?

Table 1 Clinical data of the small rectal neuroendocrine tumors n (%)

Parameter	Total (n = 120)
Tumor size in mm, mean ± SD
Endoscopy	5.47 ± 1.78
EUS	5.53 ± 1.76
Histology	5.54 ± 2.15
Endoscopic morphology
Sessile or slightly elevated	110 (91.7)
Flat	10 (8.3)
Central depression	8 (6.7)
Resection method
Conventional EMR	3 (2.5)
EMR with suction methods	70 (58.3)
ESD	47 (39.2)
Histologic grade
1	120 (100)
2	0
3	0
Histologic type
Enteroglucagon or L-cell	120 (100)
Enterochromaffin or enterochromaffin-like cell	0
Microscopic invasion
Lymphatic and vascular	1 (0.8)
Lymphatic	0
Vascular	0
Follow-up duration
6-12 mo	84 (70.00)
12-24 mo	13 (10.83)
24-36 mo	16 (13.33)
≥ 36 mo	7 (5.83)
Follow-up in day, median (range)	196 (154-2148)
Follow-up in day, mean ± SD	407.54 ± 374.16

EUS: Endoscopic ultrasound; EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection.

Table 2 Comparison among the sizes measured by endoscopy, endoscopic ultrasonography and histology

Measurement technique	Wilcoxon signed-rank test
Endoscopy and EUS	P = 0.215
Endoscopy and histology	P = 0.540
EUS and histology	P = 0.933

EUS: Endoscopic ultrasonography.

Table 3 Correlation coefficient among the sizes measured by endoscopy, endoscopic ultrasonography and histology

Measurement technique	Correlation coefficient
Endoscopy and EUS	0.914 (P < 0.01)
Endoscopy and histology	0.727 (P < 0.01)
EUS and histology	0.727 (P < 0.01)

EUS: Endoscopic ultrasonography.

Table 4 Comparison of depth of invasion measured by endoscopic ultrasonography and histology n (%)

Depth of invasion	EUS	Histology
2nd layer (muscularis mucosa)	9 (7.5)	2 (1.7)
3rd layer (submucosa)	111 (92.5)	118 (98.3)
4th layer (muscularis propria)	0 (0)	0 (0)
EUS accuracy	111 (92.5)

EUS: Endoscopic ultrasonography.