Retinoblastoma Presenting in a Child with Hypomelanosis of Ito

PURPOSE To describe a case of a child with a known history of pigmentary mosaicism suggestive of Hypomelanosis of Ito presenting with unilateral leukocoria, who was ultimately diagnosed with retinoblastoma. METHODS A report of a 16-month-old girl with pigmentary mosaicism and unilateral retinoblastoma. RESULTS A previously healthy 16-month-old girl with a diagnosis of a mosaic hypopigmentation at the age of 6 months based on a linear and whorled pattern of skin hypopigmentation along the lines of Blaschko, presented with unilateral strabismus, leukocoria, retinal detachment, and sub-retinal exudation. Hypomelanosis of Ito and other similar neurocutaneous syndromes are known to be associated with abnormal retinal pigmentation, vascular abnormalities, and retinal detachment. Examination included a fluorescein angiogram, ultrasonography, and an MRI of the brain and orbits that demonstrated features consistent with retinoblastoma. Given these findings and a flat electroretinogram, the eye was enucleated with final pathologic confirmation of retinoblastoma. CONCLUSIONS Previously unreported presentation of unilateral retinoblastoma in a child with pigmentary mosaicism.