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Intracranial meningioma with polygonal granular cell appearance in a Chihuahua
Yoshinori Takeuchi1, Yumi Ohnishi, Satoru Matsunaga
1Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan. ytake-tky@umin.net
Abstract:
A menigioma with polygonal granular cell proliferation in an 11-year and 8-month-old male Chihuahua is described. The tumor was observed under the dura matter of the right cerebrum. Microscopically, the tumor consisted of solid growth foci of small- or large- sized polygonal cells, with pale-stained nuclei, prominent nucleoli, and fine granular to foamy eosinophilic cytoplasm. Some of the proliferating cells contained variable amounts of cytoplasmic PAS-positive granules. Immunohistochemical analysis revealed that neoplastic cells were positive for vimentin and S-100 protein. Ultrastructurally, the neoplastic cells contained vesicular structures with a few small round-shaped bodies in the cytoplasm. We diagnosed the case as canine meningioma with granular cell appearance.
Insights
A rare canine meningioma with granular cell features was identified in a young Chihuahua. This brain tumor exhibited unique cellular characteristics and specific protein expressions, aiding in its diagnosis.
Area of Science:
- Veterinary Pathology
- Canine Oncology
- Neuro-oncology
Background:
- Meningiomas are common primary brain tumors in dogs.
- Granular cell changes in canine meningiomas are infrequently reported.
- Accurate diagnosis is crucial for prognosis and treatment.
Purpose of the Study:
- To describe a case of canine meningioma with granular cell features.
- To characterize the histopathological and ultrastructural findings.
- To determine the immunohistochemical profile of the tumor cells.
Main Methods:
- Histopathological examination of the tumor tissue.
- Periodic acid-Schiff (PAS) staining for granules.
- Immunohistochemical analysis for vimentin and S-100 protein.
- Ultrastructural examination using electron microscopy.
Main Results:
- The tumor was located in the right cerebrum, beneath the dura mater.
- Microscopically, it showed polygonal cells with granular eosinophilic cytoplasm and PAS-positive granules.
- Immunohistochemistry confirmed positivity for vimentin and S-100 protein.
- Ultrastructure revealed vesicular cytoplasmic structures.
Conclusions:
- The case was diagnosed as a canine meningioma with granular cell appearance.
- The findings contribute to the understanding of meningioma subtypes in dogs.
- This specific morphology and immunophenotype are important diagnostic considerations.
