Medulloepithelioma of the ciliary body: ultrasonographic biomicroscopic findings

Intraocular medulloepithelioma clinical features and management of 11 cases

AIMS

To describe the clinical features, imaging characteristics, histopathology, treatment and outcomes of intraocular medulloepithelioma.

METHODS

Medical records of 11 patients with clinically or histopathologically confirmed medulloepithelioma were retrieved and reviewed. Clinical features, diagnostic challenges, imaging characteristics, management, histopathology and prognosis were assessed.

RESULTS

The median age of the patients at initial diagnosis was 4 years, with the most common manifestations being leukocoria (five eyes), loss of vision (four eyes), ocular pain (one eye) and ophthalmic screening (one eye). The clinical signs include a grey-white ciliary body lesion, cataract or lens subluxation, secondary glaucoma and evident cysts. The ultrasound biomicroscopy (UBM) imaging most commonly displays ciliary body mass with intratumoural cysts (nine eyes). Three patients underwent surgery for cataract or glaucoma while the tumours were incidentally found. Two of the three patients managed by eye preserve treatments eventually required enucleation because of local tumour recurrence or phthisis. One patient treated with intra-arterial chemotherapy and cryotherapy had successful tumour regression and globe salvage.

CONCLUSIONS

Initial misdiagnosis, delay in diagnosis and subsequent misdirected management is not uncommon in medulloepithelioma. The presence of multiple cysts in the tumour and retrolental neoplastic cyclitic membrane detected by UBM can offer certain information. Selective intra-arterial melphalan may prevent further tumour growth, but longer follow-up is necessary until treatment efficacy is fully evaluated.

An advanced case of pediatric ciliary body medulloepithelioma with detailed literature review

INTRODUCTION AND IMPORTANCE

Medulloepithelioma is the second most common primary intraocular malignant tumor in children but is often diagnosed late, which worsens the prognosis.

CASE PRESENTATION

We are reporting a 6-year-old boy presenting with a ciliary body (CB) teratoid malignant medulloepithelioma (TMM), which was missed at the initial presentation. We added our case to the 97 previously reported cases in our literature review that were confirmed by cytological or histopathological examination.

DISCUSSION

Medulloepithelioma has a wide age range at presentation with a mean of 5.3 ± 4.1 years, and slight male predominance (M: F ratio of 1.15). Clinically, the main symptoms/ signs are reduced visual acuity, lens changes, or a pupil "mass." Almost all reported medulloepitheliomas were unilateral (98 %). Histopathologically, non-teratoid malignant medulloepithelioma (NTMM) (35.7 %) and TMM (34.5 %) were the commonest. Enucleation was the main treatment modality because of the large tumor size of 72.7 %. A combination of chemotherapy and/or radiotherapy was used in 15.1 % and brachytherapy for small lesions in 14.1 %. Orbital exenteration was needed in 3 cases because of orbital invasion.

CONCLUSION

A CB medulloepithelioma tumor can be easily missed, diagnosed late, with less chance for globe salvaging. The malignant types are more common and may result in orbital invasion, requiring even more extensive surgery. Therefore, when facing a child with lens changes, a pupil "mass," or raised intraocular pressure, pediatricians and general ophthalmologists must have an earlier suspicion and be aware of this rare entity to improve outcomes and reduce loss of vision or other disease-related morbidity.

Diagnostic imaging of the ciliary body: Technologies, outcomes, and future perspectives

The ciliary body (CB) is part of the uvea and is a complex, highly specialized structure with multiple functions and significant relationships with nearby structures. Its functions include the aqueous humor (AH) production in the ciliary processes, the regulation of the AH output through the uveoscleral pathway, and accommodation, which depends on the ciliary muscle. Also, the CB is an important determinant of angle width as it forms part of the ciliary sulcus. Until recently, knowledge of the CB was based on histological studies. However, this structure can currently be assessed in vivo using imaging techniques such as ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT). Both techniques have shown good reproducibility of their measurements allowing for quantification of CB dimensions and their localization. In effect, studies have shown a larger CB in myopia and its diminishing size with age. Swept-source OCT devices offer fast, non-invasive high-resolution imaging allowing the identification of multiple structures. UBM requires contact and is uncomfortable for the patient. However, this technique offers deeper imaging and therefore remains the gold standard for assessing the posterior chamber, ciliary processes, or zonula. The clinical utility of CB imaging includes its assessment in different types of glaucoma such as angle-closure, malignant or plateau iris. Diagnostic CB imaging is also invaluable for the assessment of ciliochoroidal detachment when suspected, the position after the implantation of a pre-crystalline or sulcus-sutured lenses, diagnosis or monitoring of cysts or tumors, sclerotomies after retinal surgery, intermediate uveitis, or accommodation.

Surgical removal of a giant iris stromal cyst: an intraoperative optical coherence tomography-guided approach

An 11-year-old girl was brought with the chief complaint of progressive diminution of vision in her right eye for the past 3 months. There was no history of ocular trauma or any ocular surgery. Systemic and family history was insignificant. Visual acuity was 20/20 in her left eye and counting finger close to face with projection of rays being accurate in her right eye. Slit lamp examination of her right eye showed large cystic lesion filling almost entire anterior chamber. With the help of various imaging modalities like anterior segment optical coherence tomography (OCT) and ultrasound biomicroscopy diagnosis of iris stromal cyst was confirmed. Right eye surgical removal of the iris stromal cyst was done under real-time imaging of intraoperative OCT (iOCT). Best-corrected visual acuity at 6 months follow-up was 20/20 without any recurrence. iOCT-guided approach for complete removal of the iris cyst seems more promising.

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.

MicroRNA profiling in intraocular medulloepitheliomas

Purpose

To study the differential expression of microRNA (miRNA) profiles between intraocular medulloepithelioma (ME) and normal control tissue (CT).

Material and Methods

Total RNA was extracted from formalin fixed paraffin embedded (FFPE) intraocular ME (n=7) and from age matched ciliary body controls (n=8). The clinical history and phenotype was recorded. MiRNA profiles were determined using the Affymetrix GeneChip miRNA Arrays analyzed using expression console 1.3 software. Validation of significantly dysregulated miRNA was confimed by quantitaive real-time PCR. The web-based DNA Intelligent Analysis (DIANA)-miRPath v2.0 was used to perform enrichment analysis of differentially expressed (DE) miRNA gene targets in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway.

Results

The pathologic evaluation revealed one benign (benign non-teratoid, n=1) and six malignant tumors (malignant teratoid, n=2; malignant non-teratoid, n = 4). A total of 88 miRNAs were upregulated and 43 miRNAs were downregulated significantly (P<0.05) in the tumor specimens. Many of these significantly dysregulated miRNAs were known to play various roles in carcinogenesis and tumor behavior. RT-PCR validated three significantly upregulated miRNAs and three significantly downregulated miRNAs namely miR-217, miR-216a, miR-216b, miR-146a, miR-509-3p and miR-211. Many DE miRNAs that were significant in ME tumors showed dysregulation in retinoblastoma, glioblastoma, and precursor, normal and reactive human cartilage. Enriched pathway analysis suggested a significant association of upregulated miRNAs with 15 pathways involved in prion disease and several types of cancer. The pathways involving significantly downregulated miRNAs included the toll-like receptor (TLR) (p<4.36E-16) and Nuclear Factor kappa B (NF-κB) signaling pathways (p<9.00E-06).

Conclusions

We report significantly dysregulated miRNAs in intraocular ME tumors, which exhibited abnormal profiles in other cancers as well such as retinoblastoma and glioblastoma. Pathway analysis of all dysregulated miRNAs shared commonalities with other cancer pathways.

Amblyopia secondary to iris cyst

CLINICAL CASE

A 5 year-old child diagnosed with moderate anisometropic amblyopia secondary to primary cyst of iris pigment epithelium. He was evaluated with ultrasound biomicroscopy (BMU) and optical coherence tomography (OCT) of anterior segment.

DISCUSSION

The OCT, although with some limitations, is a useful tool to study the anterior segment. It is probably more recommendable than BMU in the childhood.

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.

Neovascular glaucoma in a child: an unusual presentation of medulloepithelioma

A healthy 12 month old infant without significant medical history presented with left eye redness for one week. Ophthalmic examination showed elevated intraocular pressure with iris neovascularization in the affected eye with increased optic nerve cupping. Scleral depression revealed a ciliary body mass in the supratemporal quadrant. A large, non-pigmented, vascular mass was noted; biopsy results showed multilayered cords, tubules, and sheets resembling primitive medullary epithelium arising from the ciliary body. The patient was diagnosed with medulloepithelioma. The patient underwent enucleation of the affected eye. Medulloepithelioma is a rare but important cause of neovascular glaucoma in the pediatric population. This case will focus on the characteristics of medulloepthelioma and the differential diagnosis for a non-pigmented ciliary body mass in a child.

Benign intraocular teratoid medulloepithelioma causing glaucoma in an 11-year-old Arabian mare

CASE DESCRIPTION

An 11-year-old Arabian mare was presented for investigation of a visible, pale-colored intraocular mass in the right eye.

CLINICAL FINDINGS

An intraocular mass was detected clinically and ultrasonographically as originating from the superior temporal quadrant of the ciliary body and iris and causing secondary glaucoma. The echodense mass was occupying the majority of the vitreous chamber and extended into the anterior chamber. The left eye appeared normal.

TREATMENT AND OUTCOME

Enucleation was recommended for therapeutic and diagnostic purposes. No adjuvant treatment was given. Histopathological examination demonstrated a benign intraocular teratoid medulloepithelioma located at the ciliary body. Immunohistochemical studies showed that neoplastic cells were positive for vimentin, S-100 protein, neuron-specific enolase (NSE), and nestin and negative for glial fibrillary acidic protein (GFAP). Electron microscopy revealed abundant cellular matrix and blood vessels surrounding tumor cells, which had indented, round to oval nuclei. There were also apoptotic bodies and cells containing melanosomes of variable shape and size. Eight years later, the horse has had no recurrence and maintains normal vision in the left eye.

CLINICAL RELEVANCE

This is the first report of a benign teratoid intraocular medulloepithelioma in an adult horse and the ultrastructural and immunohistochemical characterization of a teratoid medulloepithelioma in this species.

Ciliary body medulloepithelioma: clinical, ultrasound biomicroscopic and histopathologic correlation

A 3-year-old girl presented with a distorted pupil and decrease of visual acuity. A ciliary body mass at the superior-temporal quadrant could be seen at slit-lamp examination. Ultrasound biomicroscopy revealed a lesion with lobulated surface, arising at the ciliary body, composed of compact and cystic areas. An iridocyclectomy was performed but the tumour recurred after a few months. The eye was then enucleated. Histopathologic evaluation showed sheets and cords of proliferated medullary epithelium. Cystic spaces and Flexner-Wintersteiner rosettes were also seen. Those findings correlated well with ultrasound biomicroscopic images. The knowledge of echographic characteristics can significantly assist in the diagnosis of medulloepithelioma of the ciliary body.

Differential diagnosis of anterior chamber cysts with ultrasound biomicroscopy: ciliary body medulloepithelioma

PURPOSE

To describe a case with motile cyst in the anterior chamber in the right eye of a 7-year-old boy.

METHODS

The right eye's visual acuity was 20/50. Intraocular pressure was 59 mmHg. Slit-lamp examination showed prominent rubeosis iridis and a grey-white mass floating freely in the anterior chamber. Ultrasound biomicroscopy revealed a cystic mass in the anterior chamber. A diagnostic cyclectomy with removal of the anterior chamber cyst was performed. Histopathology of the anterior chamber lesion showed an intact cyst composed of medullary epithelial cells. Medulloepithelioma with malignant criteria was diagnosed and the eye was enucleated.

RESULTS

Pathology demonstrated an medulloepithelioma with a few mitotic figures and nuclear pleomorphisms within the ciliary body. The patient was followed for 8 months without any metastasis in the orbit or elsewhere.

CONCLUSION

Intraocular medulloepithelioma is a rare embryonic benign or malignant neoplasm typically diagnosed in the first decade of life as a ciliary body mass. A dislodged, free-floating anterior chamber cyst associated with neovascular glaucoma is typical of medulloepithelioma in children. This unique presentation should be differentiated from congenital iris epithelial, post-traumatic, epithelial, parasitic and neoplastic cysts. Ultrasound biomicroscopy is useful for analysing the structure of the anterior segment mass. Ciliary body medulloepithelioma is characterized by echogenic mass heterogeneity and an irregular surface containing multiple cystic cavities. Lack of glial differentiation may predict a better clinical outcome in primary neuroectodermal brain tumours.