Medulloepithelioma of the ciliary body

Last revised by Craig Hacking on 20 Oct 2022

Medulloepitheliomas of the ciliary body are rare primary intraocular embryonal tumors arising from the ciliary body of the eye.

Medulloepithelioma of the ciliary body is also referred to as diktyoma or teratoneuroma of the ciliary body. It is included among the "tumors of the iris and ciliary body neuroepithelium" of the WHO classification of eye tumors 1, distinct from the analogous arising from the optic disc and optic nerve (see medulloepithelioma of the optic disc and the optic nerve).

It should not be confused with an even rarer tumor sometimes encountered within the brain; see medulloepithelioma of the brain

Medulloepithelioma of the ciliary body is a tumor of childhood with the age of onset between 2-5 years, although some cases have been reported in adults 2. There is a slight prevalence in females 3.

Medulloepithelioma of the ciliary body is composed of neuroepithelial cells similar to embryonic medullary epithelium organized in anastomosing cords, bands, and ribbons surrounded by an acellular myxoid stroma. Rarely a net-like pattern of neuroepithelial cells (referred as to a "diktyomatous pattern") is seen 1

It is classified as malignant if it shows neuroblastic cells resembling retinoblastoma, increased mitotic activity, atypia, pleomorphism, sarcomatous changes, local and/or extraocular invasion with metastasis 1.

Medulloepithelioma of the ciliary body may be occult in its initial stage 4

Medulloepithelioma of the ciliary body may appear as a heterogeneous hyperdense mass occupying the vitreous region 5. Calcifications are rarely seen 4.

Medulloepithelioma of the ciliary body appears as a heterogeneous mass in the vitreous region with the following signal features 4-6:

  • T1: isointense or mildly hyperintense to vitreous

  • T2: hypointense to vitreous

  • T1 C+ (Gd): heterogeneous contrast-enhancement due to cystic changes, but may be homogeneous 6

Tumors confined to the globe generally benefit from a gross total resection 3, whereas the prognosis is poor if there is extraocular invasion, recurrence, and/or metastatic disease 1.

Prognosis of a medulloepithelioma of the ciliary body is often affected by misdiagnosis and treatment delay 1

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