Polyps found at rectal surveillance

These polyps are found in a rectal pouch
WHAT IS THE UNDERLYING DIAGNOSIS?

■ Serrated polyposis syndrome

Polyps is SPS are flat (usually)

■ FAP

Looks like a classic example of rectal surveillance in FAP but polyps do look odd don't they?

■ Juvenile polyposis

Yes! Pt had already developed a CRC and after a subtotal colectomy offered rectal surveillance

explanation

These polyps have a funny crypt pattern, but THERE IS A PATTERN! Accordingly, they are likely to be 'hamartomatous' (a non-sensical histological term which basically means overgrowth of normal tissue). Of course, this patient has Juvenile Polyposis syndrome. Although the polyps are 'hamartomatous', as in Peutz-Jeghers syndrome, there is a stark difference. The polyps in JP often turn dysplastic and are presumably the origin of this patients adenocarcinomas. In contrast, the polyps in PJS are extremely rarely reported to harvest dysplasia (I've never seen a dysplastic polyp in PJS). 

By the way, the WHO criteria for diagnosis of juvenile polyposis syndrome are one of either:

• More than five juvenile polyps in the colon or rectum
• Juvenile polyps find in both the upper and lower gastrointestinal tract
• Any juvenile polyps found in a person with a family history of juvenile polyposis