Neuron-specific enolase and retinoblastoma. Clinicopathologic correlations

Neuron-specific enolase (a glycolytic, ubiquitous, intracellular enzyme) has recently been reported to be detectable in the aqueous humor of eyes containing retinoblastoma. Aqueous humor from 17 patients with histologically proven retinoblastoma was assayed for the presence of neuron-specific enolase (NSE). NSE was detectable in 17 out of 17 patients with levels between 619 and 60,000 ng/ml. A multitude of clinocopathological parameters were examined for statistically significant correlations with levels of aqueous humor NSE. This investigation demonstrated that only two parameters, the presence of tumor invasion into the anterior chamber, and inflammation significantly correlated with aqueous NSE levels. Histological parameters which did not correlate with aqueous NSE levels included tumor necrosis, calcification, Flexner-Wintersteiner rosettes, exophytic/endophytic tumor type, tumor extent relative to the equator, and optic nerve/choroidal invasion. Clinical parameters which showed no correlation included patient sex (M/F), enucleation age, presentation age, family history, laterality, prior treatment, and presence of metastatic disease. Neuron-specific enolase is present in the anterior chamber of eyes enucleated for retinoblastoma, but additional testing is necessary to determine the normal levels of neuron-specific enolase in children's eyes and the levels in eyes with lesions simulating retinoblastoma.