Nonteratoid Medulloepithelioma Research Articles

A case of metastatic non-teratoid ocular medulloepithelioma in an adult horse

This case reports an eight-years-old horse that presented a unilateral tumor in the left ocular orbital region diagnosed on the basis of clinical signs, gross anatomopathological and histopathological investigations. The affected area was exenteration and submitted to histopathological evaluation and was diagnosed as a non-teratoid medulloepithelioma. This is a rare ocular neoplasm that usually affects young individuals – and was composed by neuroepithelium arranged in tubules and Flexner-Wintersteiner rosettes without presence of heteroplastic components. The animals died and was submitted to post-mortem evaluation, revealing presence of medulloepithelioma metastases at the internal region of the head, lymph nodes, lungs, and liver. This neoplasm usually presents a benign frame; however, the case herein described shows that it can be highly malignant and aggressive since it can cause extensive lesions and spread metastases to visceral organs.

Medulloepithelioma of the optic disc

A 6-year-old boy with a history of an amblyopic, occasionally red left eye was found to have a solid white mass overlying the optic disc on dilated ocular fundus examination. Transvitreal endoincisional biopsy of the mass yielded neoplastic tissue consistent with intraocular medulloepithelioma. The eye was removed subsequently because of concern that the tumor may invade the retrobulbar optic nerve. Histopathologic and immunohistochemical analysis of the tumor confirmed nonteratoid medulloepithelioma of the optic disc. The child has been followed up for over 36 months without any signs of orbital tumor recurrence or metastasis.

Medulloepithelioma: invasive versus noninvasive diagnostic methods and their impacts on outcome.

The purpose of this study was to report a case of a 34-month-old patient who presented with leukoria and underwent a vitrectomy and vitreous biopsy at an outside hospital followed by definitive enucleation for a nonteratoid medulloepithelioma and to review the literature regarding metastatic rates for this tumor after intraocular surgery. The authors reviewed the clinical, histopathologic, and neuroimaging records in the unusual case of a child with medulloepithelioma who had previously undergone pars plana vitrectomy and vitreous biopsy. An in-depth literature search was performed for patients with medulloepithelioma with prior biopsy or surgery. Clinical examination showed a subluxed cataractous lens and neovascular glaucoma. Ultrasonography showed a large, cystic lesion with high reflectivity. Enucleation was performed, and histopathologic analysis showed a diffuse nonteratoid medulloepithelioma. Metastasis in medulloepithelioma is very rare. A systematic review of cases of patients with medulloepithelioma undergoing invasive intervention indicated that some patients subsequently developed metastases. Such procedures should be avoided to prevent orbital seeding or creating tracts for tumor migration and ultimate extraocular relapse.

Malignant non-teratoid medulloepithelioma of the optic nerve with intraocular extension

Medulloepithelioma is an uncommon tumour. These tumours most commonly arise in the brain and spinal cord; however, they also may arise from the optic nerve. We, herein, report a rare case of malignant non-teratoid medulloepithelioma of the optic nerve with intraocular extension.

Colossal Malignant Nonteratoid Medulloepithelioma of the Eye with Unusual Metastases: The Natural History

AbstractBackgroundMedulloepithelioma is rare intraocular tumor seen predominantly in children, and arising mainly from undifferentiated nonpigmented epithelium of the ciliary body.MethodsWe present a typical neglected case of malignant nonteratoid medulloepithelioma of the eye with extensive metastases to the facial soft tissue parotid and cervical lymph nodes.ResultsAn aggressive surgical approach with orbital exenteration and comprehensive disease clearance with total parotidectomy and neck dissection augmented by postoperative radiotherapy was utilized after initial unsuccessful chemotherapy.ConclusionsThe present case highlights the natural history of untreated medulloepithelioma of the eye. Colossal growth at the primary site with extensive regional lymph node metastases develops without distant metastases. Complete surgical excision supplemented with postoperative radiotherapy should be considered even in the setting of advanced locoregional disease.

Malignant non‐teratoid medulloepithelioma of ciliary body with retinoblastic differentiation: A case report and review of literature

We present a 6-year-old child with intraocular and extraocular mass and high intraocular pressure. The tumor mass involved a disorganized anterior segment and extended through the medial cornea and sclera. A preliminary diagnosis of retinoblastoma with extraocular extension was made. An exenteration of the left globe and orbital tissue was performed. Histological examination showed that the lesion, which occupied the posterior chamber, involved the ciliary body, extending into the iris, sclera and cornea, projecting beyond the cornea anteriorly and extending to the retina posteriorly. The tumor cells were diffusely immunoreactive to vimentin, neuron specific enolase and CD 138. The medulloepithelioma cells were focally positive to cytokeratin (AE1/AE3), cytokeratin 18, CD56,CD57, S100, HMB-45 and bcl2 while areas of retinoblastic differentiation showed diffuse immunoreactivity to synaptophysin, neurofilament and CD138 with focal immunoreactivity to calretinin. All tumor cells showed no immunoreactivity to cytokeratin 7, cytokeratin 20, epithelial membrane antigen, carcinoembryonic antigen, desmin, GFAP, and chromogranin. Nuclear staining for P53 was seen in 80% of tumor cells. The ki-67 index was 90%. The tumor was described as malignant intraocular non-teratoid medulloepithelioma with retinoblastic differentiation arising from the ciliary body. Tumor satellites were seen in the adjacent periocular soft tissue. The treatment involved exenteration of the left globe and orbital tissue with secondary skin graft following chemotherapy. The patient is well and has no recurrence after 1 year of treatment. We report that medulloepithelioma can present as a case of infantile glaucoma, can show signs of intraocular calcifications and can show retinoblastic differentiation.

Malignant Nonteratoid Ocular Medulloepithelioma in a Llama (Llama Glama)

A 6-year-old female llama presented with buphthalmos of its right eye owing to the presence of an intraocular mass. The affected globe was enucleated and submitted for microscopic examination. The intraocular mass was diagnosed as malignant medulloepithelioma. Within the following months, the llama developed soft tissue masses, which completely filled the right orbital cavity and expanded the cranial portion of the right mandibular bone, and enlarged mandibular lymph nodes. Euthanasia was elected 30 months after the initial diagnosis. The carcass was submitted for postmortem examination, which revealed the presence of medulloepithelioma metastases within the right orbit, mandible, mandibular lymph nodes, lungs, liver, and mesenteric and sublumbar lymph nodes. The primary intraocular tumor and its metastases were composed of neoplastic undifferentiated neuroepithelial cells, which formed tubules, Flexner-Wintersteiner and Homer Wright rosettes, and rare solid sheets. Electron microscopy showed that tumor cells were connected by desmosome-like junctions and contained rare intracytoplasmic basal bodies. Neoplastic cells were positive for vimentin, nestin, microtubule-associated protein 1B, S-100 protein, and glial fibrillary acidic protein (GFAP). To the best of the authors' knowledge, this is the first report of a malignant nonteratoid ocular medulloepithelioma with distant metastases in a llama and of the ultrastructural and extended immunohistochemical characterization of a nonteratoid medulloepithelioma in this species.

Diffuse Retinal Involvement in Malignant Nonteratoid Medulloepithelioma of Ciliary Body in an Adult

Diffuse Retinal Involvement in Malignant Nonteratoid Medulloepithelioma of Ciliary Body in an Adult

Malignant nonteratoid medulloepithelioma of the ciliary body in an adult

Background The authors describe a 62-year-old man with a malignant nonteratoid malignant medulloepithelioma of the ciliary body with extension into the anterior choroid and posterior chamber. He developed gradual loss of vision in his right eye, and a clinical diagnosis of malignant melanoma of the ciliary body and choroid was made. Results Histopathologic examination of the enucleated eye showed a malignant nonteratoid medulloepithelioma of the ciliary body with extension into the anterior choroid and posterior chamber. Conclusion This report provides clinicopathologic evidence that intraocular medulloepithelioma can occur rarely in an adult. The lesion clinically may mimic a malignant melanoma. The authors also summarize five previously reported cases of this unusual lesion.

NONTERATOID MEDULLOEPITHELIOMA OF THE RETINA WITH ELECTRON MICROSCOPIC AND IMMUNOHISTOCHEMICAL CHARACTERIZATION

Medulloepitheliomas are rare intraocular tumors, predominant in children, and originate mainly from undifferentiated nonpigmented epithelium of the ciliary body. These tumors rarely involve the optic nerve or the retina. They are classified as nonteratoid and teratoid types; the latter contains heterologous tissues. The teratoid variant of medulloepitheliomas involving the optic nerve or the retina is reported, in four patients only. We describe the first case of a benign nonteratoid medulloepithelioma of the retina in a 3 1/2 -year-old girl with immunohistochemical and electron microscopic characterization.

Nonteratoid Medulloepithelioma of the Retina with Electron Microscopic and Immunohistochemical Characterization

Nonteratoid Medulloepithelioma of the Retina with Electron Microscopic and Immunohistochemical Characterization

Nonteratoid Medulloepithelioma of the Retina with Electron Microscopic and Immunohistochemical Characterization

Medulloepitheliomas are rare intraocular tumors, predominant in children, and originate mainly from undifferentiated nonpigmented epithelium of the ciliary body. These tumors rarely involve the optic nerve or the retina. They are classified as nonteratoid and teratoid types; the latter contains heterologous tissues. The teratoid variant of medulloepitheliomas involving the optic nerve or the retina is reported in four patients only. We describe the first case of a benign nonteratoid medulloepithelioma of the retina in a 3 1/2-year-old girl with immunohistochemical and electron microscopic characterization.

Recurrent Medulloepithelioma of the Ciliary Body: Immunohistochemical Characteristics

A predominantly benign medulloepithelioma of the ciliary body was diagnosed in an 8-year-old girl and resected by iridocyclectomy. It recurred twice during 30 months. Highly malignant histopathologic features developed, and the eye finally perforated and had to be enucleated. No recurrence or metastases have subsequently developed. Histologically, the tumor was a nonteratoid medulloepithelioma consisting of elements resembling embryonic retina, nonpigmented ciliary epithelium, and neuroblasts, but had also areas of obvious glial and neuronal differentiation as judged by immunohistochemistry. The neuroepithelial tumor cells were positive for neuron-specific enolase, vimentin, and often for S-100 protein. The neuroblastic cells were generally positive for neuronspecific enolase and synaptophysin, but were intermixed with glia-like tumor cells positive for vimentin, glial fibrillary acidic protein, and S-100 protein. The results suggest that even a nonteratoid medulloepithelioma may be, unlike retinoblastoma, a truly multipotential tumor.

Nonteratoicl Medulloepiothelioma of the Ciliary Body

A 34-month-old girl was treated for anterior uveitis, a superiorly subluxated cataract, rubeosis iridis and secondary glaucoma of the right eye of 3 months duration. She was diagnosed as having medulloepithelioma only after a mass was subsequently identified on the anterior surface of the iris. A low grade malignant nonteratoid medulloepithelioma was found to involve the ciliary surface throughout the circumference of the enucleated right globe. These tumors are generally associated with a good prognosis for survival, but are potentially lethal when they extend extrasclerally.

Medulloepithelioma Diagnosed by Ultrasound and Vitreous Aspirate: Electron Microscopic Observations

Ultrasonography and cytologic examination of the vitreous aspirate established the correct pre-enucleation diagnosis of medulloepithelioma in the case of an 8-year-old boy. The use of a muscle hook allowed the examiner to elevate the eye and bring the ciliary body into adequate ultrasonographic view. Histopathologic examination of the enucleated eye showed a partially pigmented mass composed of elongated neuroepithelial tubules and cords arising from the ciliary body interiorly. Several tubules displayed a central lumen with rosette-like structures. The tumor was classified as a benign, nonteratoid medulloepithelioma. Electron microscopically the lumens of the rosettes contained myriad, slender microvilli, and were bordered by numerous terminal bar complexes and areas displaying zonula adherens and zonula occludens type junctions. Additionally, invaginating gap junctions, which clearly established that the tumor originated from the ciliary epithelium, were identified.