Orbital Chordoid Meningioma: a Rare Subtype of Meningioma

Chordoid meningioma: report of 5 cases and review of the literature

Chordoid meningioma is a rare, more aggressive subtype of meningioma. This study documents the histological, radiological and clinical features of seven tumours in five patients among 131 meningioma patients who were treated in the Department of Neurosurgery at Istanbul Medipol University between 2014 and 2019. There were two males and three females. All tumours were supratentorial. Surgical Simpson grade II resection was achieved in two cases, grade I in one and grade IV in two. One case relapsed and underwent further surgeries and adjuvant treatment. The chances of survival without recurrence after the Simpson grade I-II resection are high but close follow-up is recommended particularly if grade I cannot be achieved.

Chordoid meningioma: a report of ten cases

Chordoid meningioma is a rare variant of meningioma with histological features resembling those of chordoma. This tumor has a great risk of recurrence and aggressive growth (WHO grade II). This study was done to document the clinical and pathological features of ten patients with chordoid meningioma who submitted to surgery at the National Institute of Neurology and Neurosurgery in Mexico City. Clinical, histological and immunohistochemical features were examined. The age range was from 30 to 67 years old (mean, 34.2 years). Seven patients were female and three male. The duration of symptoms varied from 3.5 months to 5 years (mean, 14.1 months). No systemic symptoms were noted. The tumor was localized in eight cases in the supratentorial compartments. Histologically, the tumors were characterized by strands and cords of meningothelial cells arranged in a mucinous stroma. Two of the ten tumors showed metaplasic changes, and seven showed brain invasion. Tumor cells demonstrated CK7, EMA and focal S-100 protein and Ep-CAM. Cytokeratin AE1/AE3, GFAP and synaptophysin were negative. The MIB-1 proliferative index was from 6 to 9% (mean 7.8). PCNA Li was 6 to 20% (mean, 14), and microvascular density was 6-16 (mean, 14.5). The mean rate of the MIB-1 labeling index in recurrences was 7.1% versus 6.33% for no tumor recurrence. Chordoid meningioma, World Health Organization grade II, is an uncommon variant of meningioma with a propensity for aggressive behavior and increased likelihood of recurrence. Chordoid meningiomas are predominantly tumors of young adults with a predilection for the supratentorial location. Intraventricular location and absence of systemic manifestations, despite the presence of abundant B-lymphocytes, mast cells and low MIB-1 LI, are some of the interesting findings in the present series that need further study. Hence, a larger number of cases with adequate follow-up data need to be studied further to establish the clinical relevance of this variant.

Distinguishing chordoid meningiomas from their histologic mimics: an immunohistochemical evaluation

Chordoid meningioma, World Health Organization grade II, is an uncommon variant of meningioma with a propensity for aggressive behavior and increased likelihood of recurrence. As such, recognition of this entity is important in cases that show similar morphologic overlap with other chondroid/myxoid neoplasms that can arise within or near the central nervous system. A formal comparison of the immunohistochemical features of chordoid meningioma versus tumors with significant histologic overlap has not been previously reported. In this study, immunohistochemical staining was performed with antibodies against D2-40, S100, pankeratin, epithelial membrane antigen (EMA), brachyury, and glial fibrillary acidic protein (GFAP) in 4 cases of chordoid glioma, 6 skeletal myxoid chondrosarcomas, 10 chordoid meningiomas, 16 extraskeletal myxoid chondrosarcoma, 18 chordomas, 22 low-grade chondrosarcomas, and 27 enchondromas. Staining extent and intensity were evaluated semiquantitatively and mean values for each parameter were calculated. Immunostaining with D2-40 showed positivity in 100% of skeletal myxoid chondrosarcomas, 96% of enchondromas, 95% of low-grade chondrosarcomas, 80% of chordoid meningiomas, and 75% of chordoid gliomas. Staining with S100 demonstrated diffuse, strong positivity in all (100%) chordoid gliomas, skeletal myxoid chondrosarcomas, low-grade chondrosarcomas, and enchondromas, 94% of chordomas, and 81% of extraskeletal myxoid chondrosarcomas, with focal, moderate staining in 40% of chordoid meningiomas. Pankeratin highlighted 100% of chordoid gliomas and chordomas, 38% of extraskeletal myxoid chondrosarcomas, and 20% of chordoid meningiomas. EMA staining was positive in 100% of chordoid gliomas, 94% of chordomas, 90% of chordoid meningiomas, and 25% of extraskeletal myxoid chondrosarcomas. Brachyury was positive only in the chordomas (100%), whereas GFAP was positive only in the chordoid gliomas (100%). EMA was the most effective antibody for differentiating chordoid meningioma from skeletal myxoid chondrosarcoma, low-grade chondrosarcoma, and enchondroma, whereas D2-40 was the most effective antibody for differentiating chordoid meningioma from extraskeletal myxoid chondrosarcoma and chordoma. Our findings demonstrate that in conjunction with clinical and radiographic findings, immunohistochemical evaluation with a panel of D2-40, EMA, brachyury, and GFAP is most useful in distinguishing chordoid meningioma from chordoid glioma, skeletal myxoid chondrosarcoma, extraskeletal myxoid chondrosarcoma, chordoma, low-grade chondrosarcoma, and enchondroma. A lack of strong, diffuse S100 reactivity may also be useful in excluding chordoid meningioma. Among the neoplasms evaluated, brachyury and GFAP proved to be both sensitive and specific markers for chordoma and chordoid glioma, respectively. Of note, this study is the first to characterize the D2-40 immunoprofile in extraskeletal myxoid chondrosarcoma, results that could be of utility in differential diagnostic assessment.