🧬🧠 Turcot’s syndrome is a rare inherited cancer predisposition syndrome characterised by the association of primary brain tumours and colorectal adenomatous polyposis. It represents an overlap between familial adenomatous polyposis (FAP) and Lynch syndrome, depending on the underlying genetic defect.

📘 About

🧬 Usually autosomal dominant inheritance (with variable penetrance).
🧠🎗️ Classified as a brain–colon polyposis syndrome.
⚖️ Affects males and females equally.
🧪 Phenotype depends on whether the mutation lies in APC or DNA mismatch repair (MMR) genes.

🔗 Genetic Associations

Familial Adenomatous Polyposis (FAP) 🧬 → Mutations in APC (or β-catenin pathway) → Numerous adenomatous polyps
Lynch syndrome (HNPCC) 🧬 → Mutations in MMR genes (classically MLH1, PMS2) → Fewer polyps but high malignant potential

🧠 Types of Turcot’s Syndrome

Type	Colonic Features	Associated Brain Tumour
Type 1 (Lynch-associated)	🧪 <100 adenomas, often larger ⚠️ High malignant potential 🧬 DNA mismatch repair defect	🧠 Glioblastoma “True Turcot syndrome”
Type 2 (FAP-associated)	🌿 Numerous small adenomatous polyps 🧬 APC mutation 🔁 Resembles classic FAP	🧠 Medulloblastoma

🩺 Clinical Features

🚽 Colonic polyposis: altered bowel habit, rectal bleeding, iron-deficiency anaemia
🎗️ Colorectal cancer: weight loss, abdominal pain, anorexia, obstruction
🧠 Brain tumours: headache, vomiting, focal neurology, seizures, raised ICP
☕ Café-au-lait spots (cutaneous clue)
🧴 Benign lipomas and basal cell carcinoma

🧪 Investigations

🩸 Bloods: FBC (anaemia), U&E, LFTs, inflammatory markers
🧠 Neuroimaging: MRI brain (preferred) ± CT for acute presentations
🔍 GI assessment: Colonoscopy with biopsy of polyps
🧬 Genetic testing: APC, MLH1, PMS2 ± β-catenin

💊 Management

👨‍👩‍👧‍👦 Genetic counselling for patients and first-degree relatives
🔎 Surveillance: regular colonoscopy and interval brain imaging
🔪 Surgery: prophylactic colectomy or polypectomy; neurosurgical tumour resection
🎯 Oncology input: chemotherapy and/or radiotherapy as indicated
🤝 Multidisciplinary care (GI, neurosurgery, oncology, genetics)

📈 Prognosis

⏳ Strongly dependent on early detection of colorectal and brain malignancy
🔍 Regular surveillance significantly reduces cancer-related mortality
🧠 Outcomes improve with early identification and treatment of CNS tumours

🧠 Exam & Teaching Pearls

🧬 Glioblastoma + colon polyps = think Lynch-related Turcot
🧠 Medulloblastoma + FAP-like polyposis = APC-related Turcot
⚠️ Brain symptoms in young patients with polyposis are never incidental

✅ Conclusion

Turcot’s syndrome is a rare but high-yield inherited cancer syndrome linking colorectal polyposis and primary brain tumours. Prompt recognition, genetic diagnosis, and structured surveillance are essential to prevent malignancy and improve long-term outcomes.

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Turcot's syndrome (Brain tumor polyposis syndrome)