Diffuse Anterior Retinoblastoma with Sarcoidosis-Like Nodule

BACKGROUND: Retinoblastomas account for 4% of malignancies in children, 1-2% of which are diffuse infiltrating retinoblastomas. Diffuse anterior retinoblastoma is rare and does not involve the retina. Here, we report on a diffuse anterior retinoblastoma with large sarcoidosis-like nodules on the iris that were responsive to anti-inflammatory therapy. CASE: We present a 6-year-old girl who had anterior uveitis with white nodules on the iris and posterior surface of the cornea in her right eye. The nodules initially responded well to anti-inflammatory treatment. However, anterior segment optical coherence tomography (AS-OCT) showed that the nodules gradually grew, shrinking the iris. We then collected the aqueous humor for diagnosis. A biopsy revealed clusters of small cells with a high nuclear-to-cytoplasm ratio with partial rosette formation. Therefore, we diagnosed diffuse anterior retinoblastoma without retinal involvement and performed enucleation of the right eye. The histopathology demonstrated undifferentiated cells similar to those seen on the biopsy, and tumor cells invaded the iris stroma, posterior surface of the cornea, ciliary body, and sclera. After the enucleation, she underwent chemotherapy and remains alive. CONCLUSION: A differential diagnosis of retinoblastoma should be considered when white nodules refractory to anti-inflammatory therapy occur in the eye, even in the absence of obvious retinal masses. AS-OCT findings are useful in assessing retinoblastoma.