Medulloepithelioma (diktyoma).

Sixteen cases of medulloepithelioma are described. Clinical data and follow-up were available on 15. Four patients underwent iridocyclectomy initially; all later needed enucleation and one had an orbital recurrence. The remaining 12 patients underwent primary enucleation. All 15 patients with follow-up are alive with no evidence of tumour recurrence. It is suggested that enucleation be performed for all but the most localised tumour. Rubeosis was noted in 13 of the 16 eyes, and this may assist in making the diagnosis. The World Health Organisation histological classification of medulloepithelioma was applied, but some problems were encountered, particularly where the presence of heteroplastic brain tissue was used as a criterion for teratoid tumour and where rosettes were used as a criterion for malignancy.