Related Experiment Video
Updated: Aug 7, 2026
Primary Orthotopic Glioma Xenografts Recapitulate Infiltrative Growth and Isocitrate Dehydrogenase I Mutation
Published on: January 14, 2014
Atypical angiomatous meningioma with E-cadherin-positive inclusion bodies in a dog
Hisaki Tokuno1, Yoshiki Sugiyama2, James K Chambers1
1Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Abstract:
An 11-year-old toy poodle presented with abnormal gait. Magnetic resonance imaging revealed a demarcated intradural extramedullary mass at the dorsal medulla oblongata, which was surgically removed. Histopathologically, a well-demarcated tumor was composed of small nests of meningothelial neoplastic cells separated by abundant fibrovascular tissue. The nuclei of neoplastic cells were often eccentric due to eosinophilic cytoplasmic inclusion bodies. Immunohistochemically, the neoplastic cells were positive for E-cadherin and vimentin, and endothelial cells were positive for CD31, von Willebrand factor, and vimentin. The cytoplasmic inclusion bodies of the neoplastic cells were E-cadherin-positive and, by electron microscopy, composed of folded membrane-like structures. The tumor was diagnosed as an angiomatous meningioma with cytoplasmic inclusion bodies, which were likely cell membranes containing E-cadherin.
Insights
A toy poodle with abnormal gait had an angiomatous meningioma removed from its medulla oblongata. This rare tumor featured unique E-cadherin-positive cytoplasmic inclusions, likely representing cell membranes.
Area of Science:
- Veterinary Neurology
- Surgical Pathology
- Canine Oncology
Background:
- Intradural extramedullary masses in dogs can cause neurological deficits.
- Meningiomas are common central nervous system tumors in dogs, but angiomatous subtypes with specific inclusions are rare.
Purpose of the Study:
- To describe the clinical, imaging, histopathological, and immunohistochemical features of a unique canine angiomatous meningioma.
- To characterize the nature of eosinophilic cytoplasmic inclusion bodies within the tumor cells.
Main Methods:
- Magnetic resonance imaging (MRI) for mass localization.
- Surgical excision of the mass.
- Histopathological and immunohistochemical analysis (E-cadherin, vimentin, CD31, von Willebrand factor).
- Electron microscopy for ultrastructural examination of inclusion bodies.
Main Results:
- An 11-year-old toy poodle presented with an abnormal gait due to a dorsal medulla oblongata mass.
- Histopathology revealed a well-demarcated angiomatous meningioma with neoplastic meningothelial cells and fibrovascular stroma.
- Eosinophilic cytoplasmic inclusions within neoplastic cells were positive for E-cadherin and, via electron microscopy, appeared as folded membrane-like structures.
Conclusions:
- The diagnosed angiomatous meningioma with cytoplasmic inclusions represents a rare presentation in canine veterinary neurology.
- The inclusion bodies are likely composed of E-cadherin-positive cell membranes, offering insight into tumor cell biology.
