Coats' disease in Tanzania: first case report and literature review.

BACKGROUND Coats' disease is an exudative retinal detachment with vascular telangiectasis occurring mostly in male children, the age group most affected by retinoblastoma. OBJECTIVES Compare the differential diagnoses of Coats' disease Establish recommendation to early disease detection. MATERIALS AND METHODS A 3-year-old female child was referred to Muhimbili National Hospital (MNH), Tanzania, in September 2011. She had presented at the peripheral hospital with gradual onset of left eye leukocoria for 1 year and pain for 2 months. B-scan showed a mass in the left eye. A clinical diagnosis of retinoblastoma was made. Left eye enucleation was performed; the patient was referred to MNH, with the enucleated specimen. RESULTS Brain and orbits scan revealed no residual tumour. The globe measured 2 x 1.8 cm, the optic nerve stump measured 3 mm. A whitish mass filled the vitreous, with complete retinal detachment. Microscopy showed retinal gliosis, detachment with sub retinal PAS positive exudates, vacuolation and cholesterol clefts. Foreign body giant cells were present; telangiectatic thin-walled blood vessels were identified. Clinico-pathological findings were of stage 4 Coats' disease. CONCLUSION Coats' disease is an important differential diagnosis of retinoblastoma. Delay to detect Coats' disease leads to vision loss which necessitates eye enucleation as was in this child.