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Peutz-Jeghers Syndrome (PJS)

Etymology: Named after Jan Peutz and Harold Jeghers, who described the syndrome.

AKA: PJS

What is it? Peutz-Jeghers syndrome (PJS) is a rare, autosomal dominant genetic disorder characterized by hamartomatous polyps in the gastrointestinal tract and mucocutaneous pigmentation.

Caused by:

  • Mutation in the STK11 (LKB1) tumor suppressor gene on chromosome 19p13.3.

Resulting in:

  • Hamartomatous polyps throughout the GI tract.
  • Mucocutaneous pigmentation, particularly around the lips, oral mucosa, and digits.
  • Increased risk of gastrointestinal and non-gastrointestinal cancers.

Structural Changes:

  • Hamartomatous polyps with characteristic arborizing smooth muscle within the polyp.

Pathophysiology:

  • Loss of function of the STK11 gene results in disrupted cellular growth regulation, leading to polyp formation and increased cancer risk.

Pathology:

  • Polyps are hamartomatous and non-neoplastic but can cause complications due to intussusception and bleeding.

Diagnosis:

  • Clinical criteria: presence of mucocutaneous pigmentation and multiple hamartomatous polyps.
  • Genetic testing for STK11 mutation.

Clinical:

  • Recurrent abdominal pain due to intussusception.
  • GI bleeding.
  • Mucocutaneous pigmentation (dark brown to black macules on lips, oral mucosa, and fingertips).
  • Increased cancer risk (GI, breast, pancreatic, ovarian, cervical, testicular, and lung).

Radiology:

  • CXR: Typically normal unless complications such as metastases are present.
  • CT:
    • Polyps may be visible in the GI tract with lead point intussusception.
    • Multiple soft tissue masses with intussusception.
  • MRI:
    • Useful for detecting intussusception and identifying polyps.
  • Endoscopic Imaging:
    • Visualization of polyps with characteristic arborizing smooth muscle patterns.

Labs:

  • Genetic testing for STK11 mutation.
  • Iron deficiency anemia secondary to GI bleeding.

Management:

  • Surveillance endoscopy and colonoscopy.
  • Surgical management for complications like intussusception.
  • Cancer screening due to elevated risk of malignancy.

Radiology Detail:

  • CXR:
    • Normal unless complications present.
  • CT:
    • Detects polyps, intussusception, and complications.
  • MRI:
    • Useful for soft tissue differentiation and detecting polyps.
  • Other Imaging:
    • Endoscopy remains key for direct visualization and biopsy.

Pulmonary Function Tests (PFTs):

  • Not applicable to this condition.

Recommendations:

  • Regular endoscopic surveillance.
  • Genetic counseling for family members.
  • Cancer screening protocols.

Key Points and Pearls:

  • Hamartomatous polyps can cause intussusception and bleeding but are non-neoplastic.
  • Mucocutaneous pigmentation is a hallmark sign.
  • Strong association with increased cancer risk, particularly GI and breast cancer.
  • Early detection through genetic testing and surveillance is critical.

References:

  • Radiopaedia: Peutz-Jeghers syndrome.
  • AJR, Radiographics, and UpToDate for diagnostic and management guidelines.