Definition/General
Introduction:
Juvenile polyp is a benign hamartomatous polyp characterized by cystic glands in abundant stroma
Most common colorectal polyp in children
Also called retention polyp
No malignant potential in isolated cases
May be syndromic (juvenile polyposis syndrome).
Origin:
Arises from developmental abnormality of mucosa and submucosa
Results from cystic dilatation of crypts
Shows hamartomatous growth pattern
Inflammatory reaction to luminal contents
Retention of secretions in dilated crypts.
Classification:
Classified as hamartomatous polyp
Solitary juvenile polyp (sporadic)
Juvenile polyposis syndrome (multiple polyps)
Cronkhite-Canada syndrome (generalized polyposis)
Part of hamartomatous polyp spectrum.
Epidemiology:
Peak incidence in first decade of life
Male predominance (2:1 ratio)
Most common colorectal polyp in children
Rectosigmoid location most frequent
Indian children show similar distribution pattern.
Clinical Features
Presentation:
Rectal bleeding (most common - 90% cases)
Polyp prolapse through anus
Abdominal pain
Mucus passage
Change in bowel habits
Iron deficiency anemia.
Symptoms:
Bright red bleeding per rectum (painless)
Prolapsing rectal mass
Mucoid stools
Crampy abdominal pain
Tenesmus
Chronic anemia (large or multiple polyps).
Risk Factors:
Juvenile polyposis syndrome (genetic)
Family history of juvenile polyps
SMAD4 mutations
BMPR1A mutations
Hereditary hemorrhagic telangiectasia (overlap syndrome).
Screening:
Colonoscopy (if symptomatic)
Flexible sigmoidoscopy (rectal polyps)
Family screening (syndromic cases)
Genetic counseling (multiple polyps)
Upper endoscopy (polyposis syndrome).
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Gross Description
Appearance:
Pedunculated polyp with smooth surface
Red to pink coloration
Lobulated contour
Soft, friable consistency
Mucus-covered surface
May show surface erosions.
Characteristics:
Smooth, glistening surface
Cherry-red appearance
Cut surface shows cystic spaces
Abundant stroma visible
Edematous consistency
Easy bleeding on manipulation.
Size Location:
Size ranges from 0.5-5 cm
Rectum (80% of cases)
Sigmoid colon (15% of cases)
Pan-colonic (polyposis syndrome)
Usually solitary (sporadic cases).
Multifocality:
Usually solitary (sporadic juvenile polyp)
Multiple polyps (juvenile polyposis syndrome)
≥5 juvenile polyps (diagnostic criteria)
Associated gastric polyps (syndrome)
Family history positive (genetic syndromes).
Microscopic Description
Histological Features:
Cystic dilatation of crypts
Abundant inflammatory stroma
Surface epithelial erosions
Inflammatory infiltrate (lymphocytes, plasma cells, eosinophils)
Edematous lamina propria
Dilated capillaries.
Cellular Characteristics:
Normal epithelial cells lining crypts
Goblet cells present
No dysplastic changes
Surface regenerative atypia (secondary to inflammation)
Inflammatory cells in stroma
Fibroblasts and smooth muscle.
Architectural Patterns:
Cystic gland dilatation
Tortuous, branching crypts
Abundant stroma between glands
Surface erosions common
Granulation tissue formation
Hamartomatous architecture.
Grading Criteria:
No grading system (benign lesion)
Assessment of dysplasia (usually absent)
Inflammatory activity variable
Surface ulceration common
Regenerative changes should not be mistaken for dysplasia.
Immunohistochemistry
Positive Markers:
CDX2 (intestinal differentiation)
CK20 (colonocytes)
Ki-67 (normal proliferation pattern)
CEA (apical pattern)
E-cadherin (cell adhesion).
Negative Markers:
CK7 (usually negative)
p53 (wild-type pattern)
β-catenin (membranous pattern)
Chromogranin A (unless neuroendocrine cells)
TTF-1 (negative).
Diagnostic Utility:
CDX2 positivity confirms colonic origin
Normal proliferation markers exclude neoplasia
p53 wild-type pattern (no mutation)
β-catenin membranous (no Wnt activation)
Immunohistochemistry rarely needed.
Molecular Subtypes:
Sporadic type (isolated polyps)
SMAD4-associated (juvenile polyposis)
BMPR1A-associated (juvenile polyposis)
PTEN-associated (Cowden syndrome overlap)
ENG-associated (HHT overlap).
Molecular/Genetic
Genetic Mutations:
SMAD4 mutations (juvenile polyposis syndrome)
BMPR1A mutations (juvenile polyposis syndrome)
PTEN mutations (Cowden syndrome)
ENG mutations (hereditary hemorrhagic telangiectasia)
Sporadic cases (no specific mutations).
Molecular Markers:
TGF-β pathway disruption (syndromic cases)
BMP signaling defects
PTEN pathway alterations
Normal p53 expression
Intact DNA mismatch repair.
Prognostic Significance:
Excellent prognosis (isolated polyps)
No malignant potential (sporadic cases)
Increased cancer risk (polyposis syndromes)
Complete excision curative
Surveillance needed (multiple polyps).
Therapeutic Targets:
Polypectomy (treatment of choice)
Surgical resection (large polyps)
Surveillance colonoscopy (polyposis)
Upper endoscopy (syndromic cases)
Genetic counseling (familial cases).
Differential Diagnosis
Similar Entities:
Inflammatory polyp (reactive lesion)
Peutz-Jeghers polyp (smooth muscle bands)
Adenomatous polyp (neoplastic)
Lymphoid polyp (lymphoid aggregates)
Prolapsed hemorrhoid.
Distinguishing Features:
Juvenile polyp: Cystic glands, abundant stroma
Inflammatory polyp: Granulation tissue pattern
Peutz-Jeghers: Smooth muscle bands
Adenoma: Dysplastic epithelium
Lymphoid polyp: Lymphoid follicles.
Diagnostic Challenges:
Distinguishing from inflammatory polyps (histologic overlap)
Differentiating from Peutz-Jeghers polyps (smooth muscle)
Recognizing syndromic associations (multiple polyps)
Avoiding overdiagnosis of dysplasia (reactive atypia).
Rare Variants:
Atypical juvenile polyp (dysplastic changes)
Cronkhite-Canada syndrome (generalized polyposis)
Ruvalcaba-Myhre-Smith syndrome (PTEN-related)
Juvenile polyp with adenomatous change
Mixed juvenile-hyperplastic polyp.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
[specimen type], measuring [size] cm in greatest dimension
Diagnosis
Juvenile Polyp
Location
Location: [anatomical site in colon/rectum]
Architectural Features
Shows characteristic cystic dilatation of crypts in abundant inflammatory stroma. Hamartomatous architecture present.
Surface Features
Surface epithelium: [intact/eroded]. Surface regenerative changes present.
Inflammatory Features
Abundant inflammatory stroma with lymphocytes, plasma cells and eosinophils. Edematous lamina propria.
Dysplasia Assessment
No dysplastic changes identified. Normal epithelial maturation preserved.
Excision Status
Complete excision: [achieved/not achieved]
Final Diagnosis
Colorectal Juvenile Polyp - Benign hamartomatous lesion