squamous cell carcinoma ( scc ) after ileal pouch - anal anastomosis ( ipaa ) for ulcerative colitis ( uc ) is very rare [ 1 , 2 ] . scc is extremely sensitive to chemoradiation therapy ( crt ) , but an ileal pouch is generally considered a contraindication to radiotherapy . few cases of scc in ipaa patients have been described in the literature , with variable treatments and unpredictable outcomes . we report the successful management of an scc of the anal transitional zone ( atz ) after ipaa and systematically review the literature for ipaa - related scc . the patient has had good functional outcomes but suffered from several episodes of pouchitis . in 2014 , he was seen at the outpatient clinic due to a nodule in the anal canal which had rapidly increased in size ( fig . the patient underwent flexible pouchoscopy and examination under general anaesthesia with biopsies , pelvis mri ( fig . 2a findings were consistent with a moderately well - differentiated scc of the atz , with no evidence of distant disease ( t1n0m0 ) . we performed a systematic review of the literature to identify scc arising from the pouch or from the atz of uc patients . inclusion criteria were unequivocal diagnosis of scc that can be reasonably considered as de novo carcinoma , diagnosis of uc , and availability of adequate information . studies including patients with conditions other than uc were only included if uc patients were identifiable . available data of all patients operated on with ipaa between 1978 and 2016 were evaluated . keywords and medical subject headings ( mesh ) used were :  restorative proctocolectomy , ulcerative colitis ,   squamous cell carcinoma ,   pouch ,   ipaa ,  and  scc . the patient has had good functional outcomes but suffered from several episodes of pouchitis . in 2014 , he was seen at the outpatient clinic due to a nodule in the anal canal which had rapidly increased in size ( fig . the patient underwent flexible pouchoscopy and examination under general anaesthesia with biopsies , pelvis mri ( fig . 2a findings were consistent with a moderately well - differentiated scc of the atz , with no evidence of distant disease ( t1n0m0 ) . we performed a systematic review of the literature to identify scc arising from the pouch or from the atz of uc patients . inclusion criteria were unequivocal diagnosis of scc that can be reasonably considered as de novo carcinoma , diagnosis of uc , and availability of adequate information . studies including patients with conditions other than uc were only included if uc patients were identifiable . available data of all patients operated on with ipaa between 1978 and 2016 were evaluated . keywords and medical subject headings ( mesh ) used were :  restorative proctocolectomy ,   ulcerative colitis ,   squamous cell carcinoma ,   pouch ,   ipaa ,  and  scc . the multidisciplinary meeting recommendation for the present case was to proceed with the conventional radiation dose to the expected effects on the ileal pelvic pouch and to the nodal spread . he received a single administration of mitomycin ( 13.5 mg ) and daily capecitabine tablets during the course of radiotherapy ( 1,300 mg / day ) . 4 ) and only suffered from pain and ulceration to the skin during crt . at the 24-month follow - up , the patient has acceptable function , no incontinence nor urgency , and good control of flatus . on endoscopy , the mucosa of the pouch was healthy , but a stricture with inflammation was noticed at the pouch inlet ( fig . which did not fit inclusion criteria , only 5 papers reporting on 7 scc were available for analysis ( table 1 ) . when matching the series of several centres , including a total of 5,136 patients , only 3 cases of scc have been observed over time , corresponding to a cumulative incidence of 0.058% 25 years after ipaa [ 3 , 4 , 5 , 6 , 7 ] . five scc developed from either the atz or rectal cuff [ 7 , 8 , 9 ] and 2 from the mucosa of the pouch [ 10 , 11 ] . out of 2 patients with scc of the pouch , 1 with scc close to the ileal pouch inlet was unsuitable for crt and died 6 months after pouch excision   and 1 had pouch excision followed by crt ( mitomycin c , 5-fluorouracil , and local radiotherapy ) with no response . only 1 paper reported crt for ileal pouch - related scc arising from the rectal cuff . the patient was a 47-year - old woman , who received 5-fluorouracil , mitomycin c , and external beam radiation therapy and appeared to have a clinical response . several cases of ipaa - related cancers have been reported [ 1 , 12 , 13 ] . a systematic review of the literature suggested that the cumulative risk of  de novo  ipaa - related cancer is 0.33%   after removing dubious cases , meaning those that should have been considered either persistence or recurrence of previously treated cancer . dysplasia or cancer on the colectomy specimen is the strongest predictor of ipaa - related cancer [ 1 , 4 , 7 ] . patients with these features are 8 times more likely of developing ipaa - related cancer , irrespective of mucosectomy . seven [ 7 , 8 , 9 , 10 , 11 ] ipaa - related scc have been described , of which 5 developed from either the atz or rectal cuff [ 7 , 8 , 9 ] and 2 from the mucosa of the ileal pouch [ 10 , 11 ] ( table 1 ) . dysplasia on the specimen is considered a risk factor for scc , but metaplasia of the ileal pouch could underlie scc , especially squamous metaplasia [ 10 , 11 ] . this is poorly addressed in uc , whereas more attention is paid to the detection of dysplasia for subsequent cancer concern and surveillance . crt is the treatment of choice for anal scc , but it can also achieve complete response in up to 66% of patients with rectal scc . it is largely agreed that pelvic irradiation is contraindicated in patients with a pelvic ileal pouch because of the predictable risk of radiation enteritis , which is likely to cause pouch failure due to structural damage to the mucosa and body of the reservoir . however , no studies have addressed the actual role of radiotherapy in these patients , and these considerations might be even more interesting under the light of newer treatment regimens . one paper reported crt   for an early tumour discovered on routine anal biopsy , and no description is provided concerning the stage [ 8 , 11 ] . moreover , the patient suffered from poor function , with seepage and 20 bowel movements per day . when acute toxicity settled down , good function was restored , but the patient required diphenoxylate hydrochloride and atropine sulfate 8 times daily . no data are available concerning the long - term effects of crt and treatment outcomes . the largest series on the topic suggested that patients with rectal cancer can have ipaa , but radiotherapy before pouch surgery impairs subsequent function and increases failure rates . european guidelines currently recommend that radiotherapy should precede pouch surgery and should be avoided after ipaa , even acknowledging that the evidence for that assumption is low . indeed , scc located in the pouch body seem to be more aggressive and might be difficult to treat with radiation therapy . out of 2 patients with scc occurring in the ileal pouch , 1 with scc close to the ileal pouch inlet was unsuitable for crt and died 6 months after pouch excision , and 1 was approached with pouch excision followed by crt ( mitomycin c , 5-fluorouracil , and local radiotherapy ) but had no response . we were able to manage an scc of the ileal pouch by means of a crt protocol that achieved complete response , without the adverse effects of radiotherapy on pouch function . avoiding excessive worsening of function is important , especially in frail patients , who may suffer from serious dehydration and electrolyte loss secondary to increased ileal pouch - anal output . the early outcome was acceptable , and no particular measures were required apart from loperamide administration . in the long term , the patient did not need any surgical treatment , which is associated with a doubled risk of failure and dysfunction over time in ipaa [ 19 , 20 ] . however , the decision on how to treat patients with scc and anal cancer of the pelvic pouch needs to be individualized , and patients and their relatives should participate in the decision - making process . scheduled follow - up of the pouch is usually not recommended in uc patients without risk factors for cancer . indeed , the risk of colorectal cancer arising from the rectal remnant or atz is lower after ipaa than the lifetime risk of cancer in the general population . however , endoscopic follow - up and surveillance after ipaa probably need to be further elucidated [ 13 , 21 ] because scc may occur at some point even in patients with no known risk factor . early detection is the key to preserve the pouch in patients who develop ipaa - related scc . crt according to our regimen could be considered in scc arising from the rectal cuff or atz . this could be the first - line approach in anal scc after ipaa , but it could also be advocated for other types of cancer , hopefully increasing the success rates and survival . metaplasia of the pouch might play a role in scc , but this remains to be further elucidated . patients with pelvic pouches receiving crt should be followed up with scheduled long - term appointments including pouchoscopy to diagnose recurrence and late adverse effects of radiation . written informed consent for patient information and images to be published was provided by the patient .