Mucinous Tumour in Ileal Pouch Post Restorative Proctocolectomy and Ileal Pouch Anal Anastomosis for Familial Adenomatous Polyposis
We present a fifty-six years old female having surveillance gastroscopy and colonoscopy ten years after a restorative proctocolectomy and Ileal-pouch anal anastomosis (IPAA).
This was performed for Familial Adenomatous Polyposis (FAP).
The patient was found to have unusual patchy nodular areas of abnormal
mucosa in the ileal pouch and at the level of the anastomosis.
While malignancy is rare, risk of pouch adenomas is common and ranged between
6 to 75% 2-5 Risk factors for development of pouch adenomas
include >1000 colonic polyps and age >50 years old 5, age of pouch,
with pouches >10 years old at high risk of adenoma2
and those who have previously developed pouch adenomas.
It is unclear why the risk of malignant transformation in these patients is low,
but most cohort studies have shown adenomas to be tubular or tubulovillous
with only a small percentage demonstrating dysplasia.
To the best of our knowledge, there have been no reports of mucinous
tumours within an ileal pouch in the literature
While the incidence of malignancy within an ileal pouch is low, this case illustrates
the importance of surveillance for patients who have had restorative
proctocolectomy and IPAA for FAP.
Apart from ileal pouch malignancy, patients may also
develop anastomotic site tumours and anal transitional zone
tumours, although this is also a rare entity.
Older pouches are more at risk of malignancy. In this case, the mucinous tumour
was found thirteen years after restorative proctocolectomy and IPAA
Gastro Open J. 2015; 1(2): 59-60. doi: 10.17140/GOJ-1-109