Association of colon adenomas and skin tags: coincidence or coexistence?

Skin tag (STs) are benign connective tissue tumors of the dermis. Some researchers have argued that there is a relationship between skin tag and colon polyps, although the physiopathological mechanisms underlying this relation were not well elucidated. In this study we aimed to investigate the co-existence of colonic adenomatous polyps and ST, additionally to shed light on the physiopathological mechanisms underlying this coincidence.

A total of 45 patients aged between 18 and 60 diagnosed with adenomatous colonic polyps and 45 sex, age, and socio-demographically matched subjects, had no polyps, were enrolled as the control group. Routine blood analysis of all participants, including serum glucose, total cholesterol, low-density lipoprotein cholesterol (LDL-C), (high-density lipoprotein cholesterol (HDL-C), triglyceride, insulin, IGF-1, and EGF, were performed. The chi-square and independent sample t or Mann Whitney U test were used to determine differences between groups.

The number of participants with ST was significantly higher in the patient group (OR 7.067, p < 0.01). Serum levels of IGF-1 and EGF were statistically similar between the groups. In the subgroup analyses, no difference was found in serum levels of insulin, IGF-1, or EGF between patients with and without ST. However, higher serum levels of insulin and EGF were found in control subjects with ST (p < 0.01 and p < 0.01, respectively). For the entire study group, 67 participants had ST and 23 patients did not. Serum insulin, and IGF-1 were similar, while serum EGF levels were higher in patients with ST (p < 0.01).

Findings of the present study may show a co-existence of colonic polyps and ST. Although previous studies have indicated that insulin resistance may play a role in the pathogenesis of both lesions in diabetic and obese patients, we found no indication of a relationship in nondiabetic and nonobese patients with increased levels of EGF in patients with ST, suggesting an alternative pathogenesis in this patient group.