Makindo Medical Notes

People with Gardner syndrome carry a very high lifetime risk of colorectal cancer and several other malignancies. It is considered a subtype of Familial Adenomatous Polyposis (FAP).

📖 About

• Markedly increased cancer risk, often at a young age.
• Characterised by colonic polyposis plus extracolonic features (bone, skin, dental, and soft tissue tumours).

🧬 Aetiology

• A form of Familial Adenomatous Polyposis (FAP).
• Caused by mutations in the APC gene on chromosome 5q22.
• Inheritance is autosomal dominant with high penetrance.

🩺 Clinical Features

• 🌿 Adenomatous polyposis of the colon (hundreds to thousands of polyps).
• 🦴 Benign osteomas of the skull, mandible, and facial bones.
• 🧴 Epidermoid cysts of the skin.
• 🦷 Dental abnormalities: odontomas, supernumerary and impacted teeth.
• 🧵 Desmoid tumours and other soft tissue growths.
• 👁 Hypertrophy of the retinal pigment epithelium (CHRPE).

🎗 Cancer Risks

• 💩 Colorectal cancer: almost inevitable if untreated → requires surveillance and colectomy.
• 🟢 Small bowel cancer (4–12%) → CT/MR enterography.
• 🟤 Pancreatic cancer (≈2%) → abdominal imaging.
• 🦋 Papillary thyroid cancer (≈2%) → thyroid examination ± ultrasound.
• 🧒 Hepatoblastoma (≈1.5%) in children → regular liver USS and AFP levels.
• 🧠 Brain/CNS tumours (<1%).
• 🍲 Gastric cancer (≈0.5%) → OGD every 1–3 years.
• Other rare associations: bile duct and adrenal tumours.

🧪 Investigations

• Genetic testing → confirm APC gene mutation.
• Screening tailored to risks (colonoscopy, OGD, thyroid exam, liver USS/AFP, CT/MRI as indicated).

💊 Management

• High-risk surveillance programmes for at-risk individuals.
• 💉 Prophylactic colectomy/proctocolectomy is curative for colorectal risk.
• Endoscopic polypectomy + long-term celecoxib therapy may delay surgery in selected cases.
• Multidisciplinary care including genetics, gastroenterology, surgery, dermatology, and oncology.

📚 References

• Cancer.net – Gardner syndrome
• Oxford Handbook of Clinical Specialties – Gastroenterology/Oncology sections.
• UK BSG guidelines on familial colorectal cancer syndromes.

🧾 Clinical Case – Gardner’s Syndrome

A 25-year-old man is referred after a routine colonoscopy finds hundreds of colonic polyps. He also reports a history of multiple epidermoid cysts and dental abnormalities. Examination reveals a firm, non-tender mass on the mandible, confirmed as an osteoma on X-ray. Genetic testing identifies an APC gene mutation. 👉 Diagnosis: Gardner’s syndrome (a variant of familial adenomatous polyposis with extracolonic features). 👉 Management: prophylactic colectomy planning, dermatology follow-up, dental review, and genetic counselling for family members.