Pink-color sign in esophageal squamous neoplasia, and speculation regarding the underlying mechanism

Table 1 Characteristics of patients and lesions

Characteristics	n
Gender
Male	50
Female	4
Age (yr)
Median (range)	67 (45-82)
Lesion location
Cervical esophagus	1
Upper thoracic esophagus	10
Middle thoracic esophagus	33
Lower thoracic esophagus	17
Lesion size (mm)
Median (range)	20 (2-74)
Histological diagnosis of the marked area
LGIN	21
HGIN	37
LPM	3

LGIN: Low-grade intraepithelial neoplasia; HGIN: High-grade intraepithelial neoplasia; LPM: Cancer invading into the lamina propria.

Table 2 Associations between histologic diagnosis, keratinous layer and pink-color sign

	HGIN or invasive cancer	LGIN	P value
Pink-color-sign			0.0001
Positive	26	2
Negative	14	19
Keratinous layer			0.0007
Present	19	20
Absent	21	1

HGIN: High-grade intraepithelial neoplasia; LGIN: Low-grade intraepithelial neoplasia.

Table 3 Associations between pink-color sign and histologic findings (univariate analysis)

	Pink-color-sign positive	Pink-color-sign negative	P value
Keratinous layer			< 0.0001
Present	7	32
Absent	21	1
Cellular atypia1			0.004
Mild	1	13
Moderate	20	19
Severe	7	1
Presence of basal membrane			0.018
Yes	14	27
No	14	6
Vascular change			0.070
Severe	20	15
Mild	8	18

¹Cellular atypia was classified based on nuclear irregularity, mitotic figures, loss of polarity, chromatin pattern and nuclear/cytoplasmic ratio.

Table 4 Associations between pink-color sign and histologic findings (multivariate analysis)

	OR (95%CI)	P value
Keratinous layer		0.001
Present	1
Absent	58.8 (5.5-632)
Cellular atypia1		0.580
Mild	1
Moderate	3.5 (0.3-35.5)
Severe	3.4 (0.07-165)
Presence of basal membrane
Yes	1	0.610
No	1.6 (0.3-9.3)
Vascular change
Mild	1	0.770
Severe	1.3 (0.3-6.3)

¹Cellular atypia was classified based on nuclear irregularity, mitotic figures, loss of polarity, chromatin pattern and nuclear/cytoplasmic ratio.