Medulloepithelioma of the optic disc

Pigmented medulloepithelioma of the optic nerve: A challenging diagnostic entity

Because of its rarity, the diagnosis of optic nerve medulloepithelioma poses a real diagnostic challenge. Medulloepithelioma is a congenital tumor that derives from the primitive medullary epithelium present in the neural tube and the optic vesicle. Its classical location is the ciliary body. Cases of retinal or optic nerve locations have been rarely reported in the literature. Only 11 cases have been published in the English literature. Herein, we report the case of a 2-year-old boy who underwent enucleation of the right eye for a presumed diagnosis of right-eye retinoblastoma, based on the presence of leukocoria on ophthalmological examination. Pathological examination showed an optic nerve medulloepithelioma. A review of the literature is also discussed in our work.

Systemic adjuvant chemotherapy for advanced malignant ocular medulloepithelioma

BACKGROUND

Ocular medulloepithelioma (diktyoma) is a rare and potentially malignant paediatric tumour of the non-pigmented ciliary epithelium. Adjuvant chemotherapy can be given in advanced cases, but the indications and regimens remain to be defined. The aim was to identify whether adjuvant chemotherapy offers treatment benefit in advanced ocular medulloepithelioma.

METHODS

This was a retrospective case series of subjects referred to a single specialist ocular oncology centre for advanced ocular medulloepithelioma subsequently treated with enucleation, including those needing adjuvant systemic vincristine, etoposide and carboplatin. A case-note review was performed for included subjects meeting referral criteria. The outcomes were histopathology characteristics, recurrence, metastases and survival.

RESULTS

Between March 2010 and June 2017, four male patients (mean age 31 months) underwent enucleation for ocular medulloepithelioma. Adjuvant chemotherapy was commenced in 3 patients (75%) due to malignant histopathological features. With a mean follow-up time of 81.5 months (median 71 months, range 49-135 months) none of the patients have had recurrence, metastases or death from the tumour.

CONCLUSIONS

This series is unique in reporting the management of advanced malignant ocular medulloepithelioma with adjuvant systemic vincristine, etoposide and carboplatin for advanced tumours with malignant features. This regimen appears to be safe and may be effective in preventing metastatic spread.

A case of a tumor-like condition in the optic nerve head of a pig

A tumor-like condition of the optic nerve head of unknown etiology was found in a domestic pig. Clinical and histological manifestations suggest that the unusual tumor-like condition is probably a variant of proliferative optic neuropathy caused by unknown nonspecific damage (perhaps trauma), which was received earlier.

TUMORS OF THE NONPIGMENTED EPITHELIUM OF THE CILIARY BODY: The Lorenz E. Zimmerman Tribute Lecture

BACKGROUND

In 1970, Dr. Lorenz Zimmerman delivered the Norman McAlister Gregg Lecture entitled "The remarkable polymorphism of tumors of the ciliary epithelium." Therein, he proposed a classification of these tumors that included congenital lesions (mainly medulloepithelioma) and acquired lesions (mainly adenoma and adenocarcinoma). The classification was based on histopathologic observations without detailed clinical information.

METHODS

Review of the published literature and personal experience with tumors of the nonpigmented ciliary body epithelium.

RESULTS

Since 1970, further observations through clinical examination and advanced testing with ultrasound biomicroscopy, anterior segment optical coherence tomography, and magnetic resonance imaging have expanded our knowledge regarding tumors of the nonpigmented ciliary body epithelium. Regarding medulloepithelioma, we have learned of the common associated features of neovascular glaucoma, retrolenticular neoplastic or vascular cyclitic membrane, intralesional cysts, response to radiotherapy, and association with Dicer-1 mutation. Regarding adenoma/adenocarcinoma, improved management with surgical resection (sparing globe) can be achieved. Fuchs adenoma, also termed coronal adenoma, is commonly found histopathologically, despite its rare clinical visualization, and should be added to the Zimmerman classification.

CONCLUSION

Since Zimmerman's report on histopathologic features of tumors of the nonpigmented ciliary body epithelium, there have been numerous publications and further observations on the clinical features and management of these intriguing neoplasms.

Intraocular Medulloepitheliomas and Embryonal Tumors With Multilayered Rosettes of the Brain: Comparative Roles of LIN28A and C19MC

PURPOSE

To compare immunohistochemical and genetic overlaps and differences between intraocular medulloepitheliomas and embryonal tumors with multilayered rosettes of the brain.

DESIGN

Retrospective histopathologic, immunohistochemical, and genetic analysis of 20 intraocular medulloepitheliomas.

METHODS

(1) Review of clinical data and hematoxylin-eosin-stained sections with (2) immunohistochemical staining of paraffin sections using a polyclonal antibody against the protein LIN28A, and (3) fluorescence in situ hybridization (FISH) testing for the amplification of the genetic locus 19q13.42 involving the C19MC cluster of miRNA. Ten retinoblastomas served as controls and to determine the specificity of these biomarkers for intraocular medulloepitheliomas.

RESULTS

Nineteen of the 20 intraocular medulloepitheliomas were either diffusely or focally LIN28A positive (weak, moderate, or strong). The most intense positivity correlated with aggressive behavior such as intraocular tissue invasion or extraocular extension. None of the cases studied by FISH harbored an amplicon for C19MC. The 10 retinoblastomas were LIN28A and C19MC negative.

CONCLUSION

LIN28A has a putative role in oncogenesis and is found only in embryonic cells and malignancies. Intraocular medulloepitheliomas and embryonal tumors with multilayered rosettes of the brain both display LIN28A positivity. Only the latter, however, display amplification of the 19q13.42 locus involving C19MC, implying that other causative factors are at play in intraocular medulloepitheliomas. More aggressive tumor behavior within the eye can be partially predicted by LIN28A staining intensity.

New insights into the development of infantile intraocular medulloepithelioma

PURPOSE

To define the maturational sequence of 3 infantile intraocular medulloepitheliomas.

DESIGN

Retrospective clinicohistopathologic and immunohistochemical study.

METHODS

Immunoreactivity of paraffin sections for CRX (cone-rod homebox transcription factor) and NeuN (biomarker for neuronal differentiation) were investigated together with other biomarkers, including S100, glial fibrillary acidic protein, epithelial membrane antigen, and various cytokeratins.

RESULTS

Three infants (aged 1, 6, and 8 months) had iris neovascularization, 2 had anterior ciliary body tumors, and 1 a posterior tumor associated with a retinochoroidal coloboma. Each tumor displayed a premedullary monolayer of cuboidal epithelium that was S100(+), NeuN(-), and CRX(-) and that transitioned into a multilaminar medullary epithelium forming neurotubules with adluminal cells that were CRX(+). NeuN first appeared in ablumenal neurotubular cells in 1 tumor and was also discovered among neuroblast-appearing cells in another. The third tumor associated with a coloboma was CRX(-) and NeuN(-).

CONCLUSIONS

A simple premedullary epithelial monolayer appears to be the fundamental source for the tumor and its multilaminar medullary epithelium. CRX(+) and NeuN(+) cells within the multilayered medullary layer approximate expression patterns similar to those found in retinal development and differentiation. Discovery of these biomarkers in the neoplastic ciliary epithelium in a small number of tumors indicates preliminarily that the most anterior layers of the optic cup have a retained retinal and neuroglial differentiation potentiality. The third case was CRX(-) and NeuN(-) and possibly arose from embryonic pigment epithelium at the edge of the retinochoroidal coloboma. These immunohistochemical findings offer histogenetic and potential diagnostic insights.

Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report

Introduction

Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival.

Case presentation

A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years.

Conclusions

Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be achieved in patients with this malignant tumor.