Retinoblastoma in Turkey: Diagnosis and clinical characteristics

Retinoblastoma (RB) is the most frequent malignant intraocular tumor in childhood. Six hundred and thirty-six cases with 831 RB-affected eyes were diagnosed and treated in our specialist center between 1963-1994. The diagnosis was made by histopathologic examination in 617 cases and clinically in 19 cases. Four hundred and forty-one (69.3%) cases were unilateral and 195 (30.7%) were bilateral. Two hundred and sixty-eight (42.1%) were females and 368 (57.9%) were males. The youngest patient was 20 days old and the oldest was 16 years old at the time of diagnosis (mean: 2.2 years). In thirty-four (5.3%) cases, a family history of RB was present. Ten of these cases were unilateral and 24 were bilateral. The most frequent presenting signs were leukocoria (394 cases, 61.9%), buphthalmos (92 cases, 14.5%), and strabismus (68 cases, 10.7%). The referring initial diagnoses were correct in 519 (81.6%) cases and false-negative in 117 (18.4%) cases. The most frequent initial false-negative diagnoses of the referring physicians were buphthalmos (43 cases, 6.8%), endophthalmitis (37 cases, 5.8%), and retinal detachment (12 cases, 1.9%). Apart from these 636 cases, there were 29 false-positive RB diagnoses during the same study period for which enucleation was performed. False-positive diagnoses included endophthalmitis (9 cases), retinal dysplasia (6 cases), retinal detachment (5 cases),vitreous hemorrhage (4 cases), Coats' disease (4 cases), and toxocariasis (one case). Ancillary testing for metastasis was carried out in all cases with newly diagnosed retinoblastoma. Five hundred and ninety-eight (72%) eyes had intraocular disease and 233 (28%) had extraocular spread. Of these 233 RBs, 58 had systemic disease. Fifty-two out of 58 tumors showing systemic involvement had either optic nerve or extrascleral extension at the histopathologic examination of enucleation material. The remaining six eyes had intraocular Class IV-V RB.