Familial adenomatous polyposis is a rare condition found in 1/10000 births. Multiple bowel polyps can lead to bowel cancer if untreated. Multiple pigmented retinal lesions are present in 60 to 80% of patients with this condition.Clinical presentation and imaging:
Fundus lesions are classified in five groups: ovals pigmented with halo, small pigmented round, large pigmented round, depigmented round and small hypopigmented. They can be grouped with a bear track aspect. The lesions are asymptomatic A total number of at least four lesions is considered a good marker of the disease. Angiographic aspect is only mask or window depending on the degree of pigmentation.Pathology:
Histologically the lesions are made of one or several layers of pigmented hypertrophic epithelial cells.Genetic:
familial adenomatous polyposis is linked to a germinal mutation of the APC gene which is localized on the long arm of chromosome 5.