Treatment of perianal and vulvar extramammary Paget disease (EMPD), rare intraepithelial malignancies, is often challenging because of its potential to spread into the anal canal. However, there is still no consensus regarding the optimal resection margin within the anal canal. Between 2004 and 2014, six patients (three with perianal EMPD and three with vulvar EMPD) in which the spread of Paget cells into the anal canal was highly suspected were referred to our department. To evaluate the disease extent within the anal canal, preoperative mapping biopsy of the anal canal was performed in five out of six patients. Two patients were positive for Paget cells within the anal canal (one at the dentate line and the other at 0.5 cm above the dentate line), whereas in three patients, Paget cell were present only in the skin of the anal verge. Using 1 cm margin within the anal canal from the positive biopsy sites, we performed anal-preserving wide local excision (WLE), and negative resection margins within the anal canal were confirmed in all five patients. The remaining one patient with perianal EMPD did not undergo mapping biopsy of the anal canal because preoperative colonoscopy revealed that the Paget cells had spread into the lower rectum. Therefore, WLE with abdominoperineal resection was performed. During the median follow-up period of 37.3 months, no local recurrence was observed in all patients. Our small case series suggest the usefulness of mapping biopsy of the anal canal for the treatment of perianal and vulvar EMPD.
Anal Canal* ; Biopsy* ; Colonoscopy ; Consensus ; Follow-Up Studies ; Humans ; Paget Disease, Extramammary* ; Rectum ; Recurrence ; Skin

Treatment of perianal and vulvar extramammary Paget disease (EMPD), rare intraepithelial malignancies, is often challenging because of its potential to spread into the anal canal. However, there is still no consensus regarding the optimal resection margin within the anal canal. Between 2004 and 2014, six patients (three with perianal EMPD and three with vulvar EMPD) in which the spread of Paget cells into the anal canal was highly suspected were referred to our department. To evaluate the disease extent within the anal canal, preoperative mapping biopsy of the anal canal was performed in five out of six patients. Two patients were positive for Paget cells within the anal canal (one at the dentate line and the other at 0.5 cm above the dentate line), whereas in three patients, Paget cell were present only in the skin of the anal verge. Using 1 cm margin within the anal canal from the positive biopsy sites, we performed anal-preserving wide local excision (WLE), and negative resection margins within the anal canal were confirmed in all five patients. The remaining one patient with perianal EMPD did not undergo mapping biopsy of the anal canal because preoperative colonoscopy revealed that the Paget cells had spread into the lower rectum. Therefore, WLE with abdominoperineal resection was performed. During the median follow-up period of 37.3 months, no local recurrence was observed in all patients. Our small case series suggest the usefulness of mapping biopsy of the anal canal for the treatment of perianal and vulvar EMPD.
Anal Canal* ; Biopsy* ; Colonoscopy ; Consensus ; Follow-Up Studies ; Humans ; Paget Disease, Extramammary* ; Rectum ; Recurrence ; Skin

Background/Aims: Several studies have assessed the effect of cool temperature on colonic peristalsis. Transient receptor potential melastatin 8 (TRPM8) is a temperature-sensitive ion channel activated by mild cooling expressed in the colon. We examined the antispasmodic effect of cool temperature on colonic peristalsis in a prospective, randomized, single-blind trial and based on the video imaging and intraluminal pressure of the proximal colon in rats and TRPM8-deficient mice. Methods: In the clinical trial, we randomly assigned a total of 94 patients scheduled to undergo colonoscopy to 2 groups: the mildly cool water (n = 47) and control (n = 47) groups. We used 20 mL of 15°C water for the mildly cool water. The primary outcome was the proportion of subjects with improved peristalsis after treatment. In the rodent proximal colon, we evaluated the intraluminal pressure and performed video imaging of the rodent proximal colon with cool water administration into the colonic lumen. Clinical trial registry website (Trial No. UMIN-CTR; UMIN000030725). Results: In the randomized controlled trial, after treatment, the proportion of subjects with no peristalsis with cool water was significantly higher than that in the placebo group (44.7% vs 23.4%; P < 0.05). In the rodent colon model, cool temperature water was associated with a significant decrease in colonic peristalsis through its suppression of the ratio of peak frequency (P < 0.05). Cool temperaturetreated TRPM8-deficient mice did not show a reduction in colonic peristalsis compared with wild-type mice. Conclusion For the first time, this study demonstrates that cool temperature-dependent suppression of colonic peristalsis may be associated with TRPM8 activation.