• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.657-663
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• 2020

Objective : Metaplastic meningioma is an extremely rare subtype of World Health Organization (WHO) grade I meningioma. It has distinctive histological subtypes according to its own mesenchymal components. Owing to its scarcity, clinical or radiological features of a metaplastic meningioma are poorly described. Methods : Between 2004 and 2018, we analyzed total 1814 cases surgically proven meningioma for 15 years. Among them, metaplastic meningioma was diagnosed in 11 cases. Magnetic resonance images were taken for all patients, and computed tomography scan was taken for 10 patients. Results : WHO grade I meningiomas were 1376 cases (75.9%), 354 cases (19.5%) in WHO grade II, and 84 cases (4.6%) in WHO grade III meningiomas. Metaplastic meningioma was 11 cases as 0.8% of WHO grade I meningioma and 0.6% of entire meningiomas for 15 years. Among the entire 11 metaplastic meningiomas, five tumors (45%) were diagnosed as a lipomatous subtype with rich fat components, four (36%) as an osseous subtype with extensive bone formation and two (18%) as a xanthomatous subtype. There was no cartilaginous subtype metaplastic meningioma in our study. Lipomatous and osseous metaplastic meningioma have peculiar radiological characteristics according to mesenchymal components. Conclusion : We investigated a rare metaplastic meningioma subtype based on our 15-year surgical experience with meningiomas. Further investigation will be necessary for the clear clarification of tumor nature of this rare tumor.

• Journal of Veterinary Clinics
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• v.27 no.1
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• pp.97-101
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• 2010

A 13-year-old neutered female Maltese was referred to Veterinary Medical Teaching Hospital of Seoul National University with 8-month-history of gradually enlarging retrobulbar mass in the right eye. On the ophthalmic examinations, exophthalmos, exposure keratitis, and cataract were observed, and menace response was absent in the eye. The fellow eye was normal except for nuclear sclerosis. On the ocular ultrasonographic evaluation, a mass was identified in retrobulbar and periocular region in the right eye. Exenteration was performed in order to remove the mass. Histopathologic evaluation revealed that most part of the mass was composed of epithelial-like neoplastic cells. Invasion into adipose cells and osseous metaplasia around the mass were also confirmed. Based on the radiologic and histopathologic examination, the mass in the right eye was diagnosed as primary retrobulbar meningioma. Eleven months after the surgery, recurrence was not observed.