Fact-sheet: Gardner syndrome
Updated on 09/27/2024 at 12:40 PM
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Definition
Genetic disease related to mutation of the adenomatous polyposis coli (APC) tumor suppressor gene on chromosome 5q, autosomal dominant in 80% of cases and due to de-novo mutation in 20%.
This syndrome is a variant of Familial adenomatous polyposis (FAP).
It is characterized by:
- colorectal polyposis,
- osteomas of the mandible, skull, and long bones,
- mesenteric desmoid tumors or soft tissue desmoid tumors
- highly polymorphic dento-maxillary lesions: odontomas, supernumerary teeth, and impacted teeth
- epidermoid cysts
Clinical features
Prevalence: between 1/8300 and 1/16000.
Colorectal polyposis: Colonic polyps usually develop during the second decade of life.
Skeletal involvement:
- >90% of patients have skeletal abnormalities, the most common of which are osteomas.
- Osteomas can involve the entire skeleton but predominate in the skull, paranasal sinuses, and mandible.
- Mandibular lesions predominate at the mandibular angle and are often associated with facial deformity. Most patients have between 3 and 6 bone lesions.
Dental abnormalities: odontomas, supernumerary teeth, and impacted teeth.
Cutaneous epidermoid cysts are common.
Mesenteric or extra-abdominal desmoid tumors: affect approximately 10% of patients.
Management
High rate of malignant transformation of intestinal polyps into adenocarcinoma: By age 30, 50% of patients will have developed colorectal carcinoma. This frequency approaches 100% in older patients --> Prophylactic colectomy is usually recommended.
Removal of mandibular osteomas and epidermoid cysts is possible for cosmetic reasons.