Malignant Nonteratoid Ocular Medulloepithelioma in a Llama (Llama Glama)

Abstract

Abstract. 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).

First description of an olfactory neuroblastoma in goldfish Carassius auratus: a case report

“…The main morphological features of ONB in goldfish were the presence of cuboidal or columnar eosinophilic cells arranged in solid nests and FW rosettes closely associated with myelinated fibres in the fibrovascular stroma, as was corroborated by Tolivia staining. Although medulloepitheliomas in mammals usually exhibit FW rosettes (Dubielzig 2002, Vajaranant et al 2005, Schoeniger et al 2006, in the case report documented for C. auratus, only Homer-Wright rosettes were occasionally observed (Bartlett et al 2010). On the other hand, the schwannomas described in goldfish were composed of elongated pale cells densely packed and organised in parallel ranks with distinctive palisading of their nuclei (Marino et al 2007).…”

Disorders of the Neurologic System and Special Senses

“…These include melanoma, retinoblastoma, and both teratoid and nonteratoid medulloepithelioma. 104,[147][148][149][150] Masses may be visible on ophthalmic examination. Removal of the globe is usually curative.…”

Ocular glioneuroma with medulloepitheliomatous differentiation in a goldfish (Carassius auratus)

“…29 In the present case, the positive results obtained for vimentin and GFAP are in accordance with the results reported in a human case, 14 and in domestic and nondomestic animal cases of medulloepithelioma. 5,30 The Hu proteins (especially HuD) are recognized as one of the earliest markers of the neuronal phenotype, 25 as such proteins suppress neuroblast proliferation and promote neuronal differentiation. 22 Antibodies to HuC/D have been extensively used to label all enteric neurons in mammals, 7 birds, 20 and also fish.…”

“…12 Isolated cases have been reported in other species, including birds 5 and llamas. 30 The present study describes the histomorphological and immunohistochemical features of a spontaneous intraocular tumor suggestive of a glioneuroma with medulloepitheliomatous differentiation in an adult goldfish (Carassius auratus).Glioneuroma and medulloepithelioma may arise from either the outer or the inner layer of the optic cup and from primitive medulloepithelium. 24 It is generally thought that medulloepithelioma is a true neoplasm originating from developing embryonal retinal cells, while glioneuroma is regarded as a choristomatous malformation consisting of glial and neuronal cells without obvious neoplastic potential.…”

“…12 Isolated cases have been reported in other species, including birds 5 and llamas. 30 The present study describes the histomorphological and immunohistochemical features of a spontaneous intraocular tumor suggestive of a glioneuroma with medulloepitheliomatous differentiation in an adult goldfish (Carassius auratus).…”