[Coats' disease. Important differential diagnosis for retinoblastoma].

Advanced Coats' disease is one of the most difficult differential diagnoses of retinoblastoma in early childhood. We describe the clinical and histological findings in two boys, ages 9 months and 21 months, with unilateral leucocoria. Despite comprehensive diagnostics that included examination under general anaesthesia, magnetic resonance imaging, and ultrasound, retinoblastoma could not be excluded, and the eyes were enucleated. Histological diagnosis of Coats' disease was confirmed. Because differentiation between retinoblastoma and Coats' disease may be difficult, enucleation seems to be indicated in uncertain cases due to the reduced visual prognosis and the risk of secondary complications in advanced Coats' disease.