Liu Zhong Hui, Foo Dominic Chi Chung, Law Wai Lun, Chan Fion Siu Yin, Fan Joe King Man, Peng Jun Sheng
Department of Surgery, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, China.
Department of Surgery, The University of Hong Kong, The University of Hong Kong-Shenzhen Hospital, Shenzhen, Guangdong Province, China.
PLoS One. 2017 Oct 31;12(10):e0186668. doi: 10.1371/journal.pone.0186668. eCollection 2017.
The association of melanosis coli with the development of colorectal polyps remains uncertain.
From a total of 18263 patients who had received colonoscopy in our hospital, 219 with melanosis coli cases and 438 controls matched by age and sex (at 1:2 ratio) were included in this study. The association of incidence, number, location, and pathology of colorectal neoplasm with grades and distribution of melanosis coli were analyzed.
Melanosis coli was associated with significantly more colorectal polyps than control, a higher incidence of numerous colorectal polyps (number ≥ 20) (7.3% vs 0.5%; p < 0.001), and higher number of small colorectal polyps (diameter ≤ 5 mm; p < 0.01). Patients with melanosis coli had higher incidences of low-grade adenomas (31.1% vs 23.3%, p < 0.05) and non-adenoma polyps (20.1% vs 12.8%, p < 0.05) than the controls. On multivariate analysis, melanosis coli was independently associated with increased detecting rates of low grade adenoma (OR = 1.54; 95%: 1.06-2.23; p < .05), non-adenoma polyp (OR = 1.72; 95%: 1.11-2.70; p < .05) and numerous polyps (OR = 16.2, 95%: 3.66-71.6; p < .05). There was no significant difference in the incidence of high-grade adenomas or adenocarcinomas in the two population groups, but the numbers of these lesions were insufficient to permit firm conclusions. No significant differences in incidence, number, and pathology of colorectal polyps between individuals with melanosis coli of three different grades of severity were found. Melanosis located predominantly in the right colon had an interestingly lower incidence of colonic polyps in right colon than did melanosis located predominantly in the left colon or total colon (8.9% vs. 26.3%, 24.0%, p < 0.05). Patients with melanosis coli had significantly more nonspecific distal ileal ulcers than did controls (8.0% vs 0%, p < 0.001).
Melanosis coli is associated with a higher incidence and number of colonic non-adenoma polyps and low-grade adenomas, and higher incidence of distal ileal ulcers. Melanosis coli may not be a harmless pigmentation, but a sign of chronic injury of colonic and intestinal mucosa.
结肠黑变病与结直肠息肉发生之间的关联仍不明确。
在我院接受结肠镜检查的18263例患者中，纳入219例结肠黑变病患者，并按年龄和性别以1:2的比例匹配438例对照。分析结直肠肿瘤的发病率、数量、位置及病理与结肠黑变病分级和分布之间的关联。
结肠黑变病患者的结直肠息肉明显多于对照组，多发结直肠息肉（数量≥20个）的发生率更高（7.3% 对0.5%；p<0.001），小的结直肠息肉（直径≤5mm）数量也更多（p<0.01）。结肠黑变病患者低级别腺瘤（31.1%对23.3%，p<0.05）和非腺瘤性息肉（20.1%对12.8%，p<0.05）的发生率高于对照组。多因素分析显示，结肠黑变病与低级别腺瘤（OR = 1.54；95%：1.06 - 2.23；p<0.05）、非腺瘤性息肉（OR = 1.72；95%：1.11 - 2.70；p<0.05）及多发息肉（OR = 16.2，95%：3.66 - 71.6；p<0.05）的检出率增加独立相关。两组人群高级别腺瘤或腺癌的发生率无显著差异，但这些病变的数量不足以得出确切结论。不同严重程度的结肠黑变病患者在结直肠息肉的发病率、数量及病理方面未发现显著差异。主要位于右半结肠的结肠黑变病患者，其右半结肠息肉的发生率有趣地低于主要位于左半结肠或全结肠的结肠黑变病患者（8.9%对26.3%、24.0%，p<0.05）。结肠黑变病患者非特异性远端回肠溃疡明显多于对照组（8.0%对0%，p<0.001）。
结肠黑变病与结肠非腺瘤性息肉及低级别腺瘤的较高发病率和数量相关，且远端回肠溃疡的发生率较高。结肠黑变病可能并非无害的色素沉着，而是结肠和小肠黏膜慢性损伤的标志。
