Hyperplastic polyp

The hyperplastic polyp of the colon and rectum is a very common. It is commonly abbreviated HP.

Hyperplastic polyp
Diagnosis in short
Hyperplastic polyp. H&E stain.
LM	serrated architecture at the surface without glandular abnormalities
Subtypes	microvesicular serrated polyps (MVSPs), goblet cell serrated polyps (GCSPs)
LM DDx	sessile serrated adenoma, normal colon, hyperplastic polyp with perineuromatous stroma, other gastrointestinal polyps
IHC	Chromogranin A +ve (increased scattered Chromogranin A-positive cells in relation to normal mucosa)
Gross	usually rectum or sigmoid, typically < 5mm
Site	cecum, colon, rectum
Syndromes	serrated polyposis syndrome
Symptoms	asymptomatic
Prevalence	very common
Endoscopy	pedunculated or sessile
Prognosis	good
Clin. DDx	normal colon, sessile serrated adenoma

Hyperplastic polyp
External resources
EHVSC	10190

The stomach lesion is dealt with in hyperplastic polyp of the stomach.

General

• Most common type of polyp:
  • Approximately 90% of all colonic polyps.
• May be part of serrated polyposis syndrome (previously known as hyperplastic polyposis syndrome).

Gross

Features:

• Flat lesion, usually <= 5mm.
• Typically in the distal large bowel (rectum, sigmoid colon).

Microscopic

Features:

• Irregular crypt architecture - tortuosity.
• Serrated epithelial cells (at the surface of the gland) - only colorectal polyps - key feature.
  • Serrated appearance = saw-tooth appearance, epithelium has jagged edge.

Notes:

• Significant negatives:
  • No nuclear atypia; glands darker staining deep... lighter staining luminal.
  • In the colon goblet cells should be present (as is usual).
• Inflammation -- cryptitis or even crypt abscesses -- is considered to arise due to trauma.^{[citation needed]}
  • It is usually not reported.

DDx:

• Sessile serrated adenoma.
• Normal colon.
• Xanthomatous polyp with hyperplastic features.
• Hyperplastic polyp with perineuromatous stroma.

Images

• 

  HP - low mag. (WC)

• 

  HP - intermed. mag. (WC)

• 

  HP - intermed. mag. (WC)

• 

  HP - high mag. (WC)

www:

• Microvesicular HP (flickr.com/jhetzel).
• HP of colon (flickr.com/jian-hua_qiao_md).

Subclassification

• Usually not subclassified as there is no demonstrated prognostic significance; the subtyping is an academic exercise.

HPs may be subclassified into two groups:

1. Microvesicular serrated polyps (MVSPs).
2. Goblet cell serrated polyps (GCSPs).

Features of the HP subtypes:

Subtype	Histology	Mutations	Clinical relevance
Microvesicular	microvesicles at the surface, serration at the surface to the mid portion of glands	BRAF V600E, CIMP	possible sessile serrated adenoma precursor
Goblet cell	superficial goblet cells, serration at the surface	KRAS	unknown; probably benign

Notes:

• CIMP = CpG island methylation phenotype.

IHC

• Chromogranin A increased scattered Chromogranin A-positive cells (in relation to normal colorectal mucosa).
  • Sessile serrated adenoma is completely negative for Chromogranin A.

Sign out

POLYP, RECTUM, POLYPECTOMY: 
- HYPERPLASTIC POLYP.

POLYP, SIGMOID COLON, POLYPECTOMY: 
- HYPERPLASTIC POLYP.

POLYP, DESCENDING COLON, POLYPECTOMY:
- HYPERPLASTIC POLYP.

POLYP, TRANSVERSE COLON, POLYPECTOMY:
- HYPERPLASTIC POLYP.

COLONIC POLYP, 35 CM, POLYPECTOMY: 
- HYPERPLASTIC POLYP.

POLYP, LARGE BOWEL AT 10 CM, EXCISION: 
- HYPERPLASTIC POLYP.

Numerous hyperplastic polyps

COLONIC POLYP(S), POLYPECTOMY: 
- HYPERPLASTIC POLYP, SEE COMMENT.  

COMMENT: 
Eight pieces of tissue were received.  On microscopy eight pieces of tissue 
are identified and all eight (individually) have the diagnostic features of a
hyperplastic polyp.  If these fragments all represent individual polyps and more
polyps of this type are present in the individual, it raises the possibility of 
a serrated polyposis syndrome.

Superficial changes only

TRANSVERSE COLON (POLYP), BIOPSY:
- COLORECTAL-TYPE MUCOSA WITH SURFACE HYPERPLASTIC CHANGE.
- NEGATIVE FOR DYSPLASIA.

Micro

Goblet cell type

The sections show colonic-type mucosa with superficial serrations rich in goblet cells. There are no serrations in the crypt base and there is no crypt base dilation. No dysplasia is present.

Generic

The sections show colonic-type mucosa with superficial serrations. There are no serrations in the crypt base and there is no crypt base dilation. No dysplasia is present.

Alternate

The sections show two tissue fragments of colorectal-type mucosa. One fragment has no pathologic change. The second fragment has the changes of a hyperplastic polyp (superficial serrations, no serrations in the crypt base, no crypt base dilation).

Minimal crypt base dilation

The sections show colonic-type mucosa with superficial serrations. Rare serrations are seen focally near the crypt base. Rare mild crypt base dilation is seen. No hockey stick-shaped glands are identified. No crypt branching is seen. No dysplasia is present.

See also

• Gastrointestinal tract polyps.
• Gastrointestinal pathology.
• Hyperplastic polyp with perineuromatous stroma.

External links

• Hyperplastic polyps (cap.org)/