Table 4. Endoscopic features of non-ampullary duodenal lesions.

Lesion type	Endoscopic features of lesions	Anatomic localization ordered by frequency in the duodenum	Paris endoscopic classification	No. of patients (%)	Spigelman stage	Histology
1a	Flat elevated whitish lesions, < 10 mm	2nd, 3rd portion and bulb	0 – IIa	37/62 (59.7 %)	I, II, III, IV	Tubular adenomas with low grade dysplasia
1b	Flat elevated whitish lesions, > 10 mm	2nd, 3rd portion and bulb	0 – IIa	7/13 (53.8 %)	III, IV	Tubular or tubulovillous adenomas with low grade dysplasia
2a	Flat elevated whitish lesions, with reddish central depression, 3 – 10 mm	2nd and 3rd portion	0 – IIa + IIc	4/13 (30.8 %)	III, IV	Tubular or tubulovillous adenomas with low grade dysplasia, tubular adenomas with high grade dysplasia
2b	Flat elevated whitish lesions, with reddish central depression, 10 – 50 mm	2nd portion and bulb	0 – IIa + IIc	3/13 (23.1 %)	III, IV	Tubulovillous adenomas with low or high grade dysplasia
3	Sessile polypoid lesions, 10 – 40 mm	2nd portion and bulb	0 – Is	1/13 (7.7 %)	IV	Tubulovillous adenomas with high grade dysplasia