atypical meningioma

atypical meningioma

A meningioma with a worse prognosis than typical meningiomas, which is characterised by cytologic atypia, increased cellularity, small cells with high nuclear:cytoplasmic ratios, prominent nucleoli, patternless or sheet-like growth, patchy necrosis, and ≥ 4 mitoses/10 HPFs.
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Heterogeneous appearance and enhancement, oedema around the lesion, and irregular cerebral surface are not consistent and specific neuroimaging features for diagnosing atypical meningioma.3 Atypical/anaplastic have relatively high incidence of brain invasion at the time of surgery which relates to their higher recurrence rate.4
Nonetheless, the revision of some morphological criteria has been performed in 2016, allowing the classification of benign arachnoid cell proliferations into atypical meningioma type.
(3,4) Our case demonstrates the first atypical meningioma reported with a metastasis to our knowledge.
The surgical pathology revealed atypical meningioma with focal clear cell change (World Health Organization Grade II), and the labeled index of immunohistochemical stain for Ki-67 is about 10%.
Metachronous secondary atypical meningioma and anaplastic astrocytoma after postoperative craniospinal irradiation for medulloblastoma.
WHO grade 2 consists of four cases (8%) of meningioma, among them three cases were of atypical meningioma, and one case (2%) of clear cell meningioma.
Twenty-seven cases of WHO grade I meningiomas would have increased in grade to atypical meningiomas (WHO grade II), and one atypical meningioma would have increased to anaplastic meningioma (WHO grade III).
The extent of surgical resection and the aggressiveness of the tumor cells are the key factors to the tumor recurrence.[sup][5],[6],[8],[9],[10] There is no general consensus for the management of atypical meningiomas. Surgery is recognized as the standard and effective treatment to all meningiomas.[sup][2],[9],[10],[11] For anaplastic meningiomas, radiotherapy is considered necessary because of the potential for recurrence and aggressive behavior,[sup][2],[9],[10],[11] but this adjuvant therapy is controversial in the treatment of atypical meningiomas, especially for those who undergo total surgical tumor resection.[sup][5],[6],[10],[11] The objective of this clinical study is to review the outcome of newly diagnosed patients with atypical meningioma after therapy.
of cases Percentage of cases Transitional meningioma 52 58.4% Meningothelial meningioma 11 12.4% Psammomatous meningioma 09 10.1% Angiomatous meningioma 06 6.7% Atypical meningioma 04 4.5% Fibroblastic meningioma 03 3.4% Anaplastic meningioma 01 1.1% Microcystic meningioma 01 1.1% Secretory meningioma 01 1.1% Metaplastic meningioma 01 1.1% TOTAL 89 100% TABLE No.
% Astrocytic Low grade 2 5.85 Astrocytoma Tumour High grade 5 14.27 Astrocytoma Neuroepithelial Glioblastoma 5 14.27 Tumours Ependymal Tumours 1 2.85 (Ependymoma) Embryonal Tumours 1 2.85 (Primitive Neuroectodermal Tumours) Tumours Meningioma 7 20 Meninges Atypical Meningioma 1 2.85 Tumours of Schwannoma 4 11.42 Cranial and Spinal Germ cell Tumour 1 2.85 Nerves Tumours of 1 2.85 Sellar Region (Cranio- pharyngioma) Cystic Epidermoid Cyst 1 2.85 Lesions Mucocele 1 2.85 Arachnoid Cyst 1 2.85 Hematoma 1 2.85 Local Extension of Rhabdomyosarcoma 1 2.85 of skull Regional Tumours Squamous cell 1 2.85 Carcinoma Follicular Carcinoma 1 2.85 of Thyroid

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