Juvenile Polyposis of the Gastrointestinal Tract
Definition
- Juvenile polyps, either multiple or involving extra-colorectal sites
Alternate/Historical Names
- Generalized juvenile gastrointestinal polyposis
- Juvenile polyposis coli
Diagnostic Criteria
- Multiple or generalized or familial juvenile polyps (any one of the following):
- ≥5 colorectal juvenile polyps
- Most cases have many more (50-200)
- Note that in sporadic cases, 2 or 3 polyps is common
- Juvenile polyps in the stomach or small intestine
- In some cases the stomach is preferentially involved
- As single juvenile polyps cannot reliably be distinguished from gastric hyperplastic polyps, this effectively requires the identification of multiple polyps for diagnosis
- 1 polyp anywhere if a first degree relative has juvenile polyposis
- Some include anyone in a juvenile polyposis kindred who develops GI carcinoma, even if a juvenile polyp cannot be found
- Polyps are generally similar to sporadic juvenile polyps
- Spherical polyps with cystic glands and inflammatory stroma (see Sporadic Juvenile Polyps for detailed criteria)
- 15% may be multilobated, papillary or villous in structure
- May have intestinal, pyloric and foveolar differentiation
- Small amounts of smooth muscle may be present
- Mucosa between polyps may also show inflammation and mild crypt dilation
- Dysplasia may be present in about 30% of syndromic cases
- Very rare in sporadic polyps
- More common in multilobated polyps or those with specialized differentiation
- Usually within the polyp, without surface involvement
- Usually low grade but may be high grade
- Must be distinguished from reactive/regenerative atypia
- Pure adenomas may occasionally occur
- Significantly elevated incidence of colorectal and gastric adenocarcinomas
- Colorectal adenocarcinoma
- 20% at age 35
- 68% at age 68
- Gastric adenocarcinoma
- 20% in patients with involvement of stomach by polyps
- Rare cases in duodenum and pancreas
- Polyps typically present in childhood, see Clinical
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting / last update: 12/27/09, 1/31/16
