A simple polyp?

This polyp was found in a 30 year old patient with a family history of bowel cancer undergoing colonic surveillance because of a 'polyp syndrome'.
WHAT IS THE LIKELY POLYP SYNDROME?

a) Familial Adenomatous Polyposis (FAP)

INCORRECT!

b) Peutz-Jeghers syndrome

INCORRECT!

c) MUTYH associated polyposis (MAP)

INCORRECT!

d) Serrated Polyposis Syndrome)

CORRECT!

e) Lynch Syndrome (formerly HNPCC)

INCORRECT!

explanation

This proved to be a difficult question and only 15% of our facebook group got the correct answer of:  Serrated Polyposis Syndrome !!! 

The odd thing about this polyp is that it appears to be a tubular adenoma (slit-like crypts) arising from a broad somewhat odd looking fold.  The 'fold' is actually a larger hyperplastic polyp.  Of course large hyperplastic polyps are now referred to as 'sessile serrated lesions' (SSL's). You are looking at an SSL, sprouting a TA !?   A 'purist' histopathologist may refer to this entity as a 'mixed serrated, adenomatous polyp'.  

Do you know of a polyp syndrome where patients have a mixture of SSL's and adenomatous polyps? Of course, the  serrated polyposis syndrome 'SPS' (previously called the sessile serrated polyposis syndrome).   It's now realised that many patients with serrated polyposis syndrome actually have a mixture of serrated and adenomatous polyps. It's possible that these patients have a greater risk of developing cancer.    The correct answer is therefore 'A' ! 

The BSG has published a 'position statement' on the topic of SSL's which is well worth reading.  The BSG sensibly recommend annual surveillance until all serrated polyps above 5mm have been cleared, following which the surveillance interval may be reduced. This is because patients with SPS do not seem to have a higher risk of developing cancer than patients with Lynch syndrome.