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Page 8 of 13 Ambe et al. Mini-invasive Surg 2018;2:37 I http://dx.doi.org/10.20517/2574-1225.2018.45

Figure 3. Placement of a transanal decompression tube into the ileal pouch at the end of ileal pouch anal anastomosis

Genetic testing for MAP is recommended in patients with clinical features of FAP or aFAP without iden-
tifiable APC mutation. The gene is included in all gene panels for hereditary GI predisposition and is not
infrequent in this setting.

Colonoscopic surveillance is recommended in individuals with MAP typically starting in their mid-20’s.
There is no indication for prophylactic surgery without neoplastic changes. Subtotal colectomy is the proce-
dure of choice in MAP patients with CRC or severe dysplasia or a high polyp burden. Relative indications
for surgery include troublesome colonoscopy or the situations when polyps become too large to be removed
endoscopically.

HAMARTOMATOUS POLYPOSIS SYNDROMES
Peutz-jeghers syndrome (PJS) is a genetic syndrome associated with hamartomatous polyposis with an
increased risk of CRC and other malignancies. Similar syndromes with predisposition to colonic polyposis
include juvenile polyposis syndrome (JPS) and Cowden syndrome. PJS is caused by mutations in STK11
[52]
- gene . Mutations in SMAD4 and BMPR1A genes have been identified in 40%-60% of patients with
[55]
JPS [53,54] . Mutations in the PTEN gene are found in over 80% of patients with Cowden syndrome .
One of the most characteristic feature of PJS is the development of multiple hamartomatous polyps of both
[56]
the small (60%-90%) and large (50%-70%) intestines . Symptoms usually occur in teenage years, however
in our series children with polyp-related intussusception and emergency surgery under the age of eight
years much higher than anticipated (5% of all PJS patients). Intussusception, gastrointestinal bleeding and
bowel obstruction are commonly the first clinical symptoms, apart from the lentiginosis pigmentosa of the
[57]
lips .
Mucocutaneous pigmentation on the lips, periorbital region and buccal mucosa are very consistent in pa-
tients with PJS. This mucocutaneous pigmentation in association with hamartomatous polyps are virtually
diagnostic for PJS in an individual with a family history of PJS [58,59] . The lifetime risk of cancer development
[60]
in patients with PJS has been reported to be as high as 85% . Cancers of the GI have been thought to oc-
[61]
cur in about three quarters of PJS patients including a close to 40% risk for CRC .