Diffuse Anterior Retinoblastoma without Retinal Involvement

Purpose: To present a unique case of an 8.5-year-old child with unilateral, anterior, pseudouveitis. He was found to have unilateral, invasive, small blue cell tumor of the anterior segment that was diagnosed as diffuse infiltrating retinoblastoma despite lack of retinal involvement on fundus examination or histopathologic analysis. Design: Interventional case report. Participants: One patient. Intervention: The patient was treated with topical prednisolone acetate 1% and oral prednisone with no improvement in anterior chamber reaction. The patient underwent fine-needle aspiration biopsy (FNAB) of anterior chamber fluid, the results of which were consistent with a primitive neuroectodermal neoplasm, either retinoblastoma or medulloepithelioma. Retinoblastoma was favored strongly, and the patient underwent enucleation followed by chemotherapy with vincristine, carboplatin, and etoposide, and radiation to the eye socket of 4140 cGy total was performed. Main Outcome Measures: The patient is alive and tumor free with follow-up of 5 years. Results: Microscopic examination demonstrated cells similar to those seen on the FNAB infiltrating the iris stroma, trabecular meshwork, Schlemm's canal, and the inner portion of sclera in the region of the angle. No calcifications were identified. Serial sections of the entire globe were performed to determine the origin of the tumor. No retinal involvement was identified, and tumor was not seen to arise from the ciliary epithelium. Immunohistochemistry demonstrated positive staining with synaptophysin and negative staining with leukocyte common antigen and CD34. Conclusions: This patient represents a case of diffuse anterior retinoblastoma with lack of obvious retinal involvement. Morphologic features typical of medulloepithelioma were not found on pathologic analysis. Although the patient lacked a retinal focus, he is alive at 5 years without evidence of recurrence of tumor.