Distinguishing Chordoid Meningiomas From Their Histologic Mimics

Abstract

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.

Specificity of brachyury in the distinction of chordoma from clear cell renal cell carcinoma and germ cell tumors: a study of 305 cases

“…Chondrosarcoma, the most recognized differential diagnostic consideration for chordoma, has been thoroughly evaluated in previous studies and does not express brachyury. 2,[5][6][7][8][9] However, within the spectrum of genitourinary neoplasia, metastatic germ cell tumors and clear cell renal cell carcinomas may also be close morphological mimics of chordoma, particularly on a small biopsy sample. Immunoreactivity with the brachyury antibody has been reported in a few germ cell tumors, either in cases without reported subtype 5 or in seminomas; 3 however, a full characterization of staining by tumor subtype has not been evaluated in a large series.…”

AMOR Vol. 2, Issue 3, 2016

“…Additionally, all chordomas (75/76), except a sarcomatous one, were positive while chondrosarcomas were negative [39] . Overall, brachyury appears to be a sensitive and fairly specific marker for chordoma, useful in distinguishing chordomas, including those occurring in extra-axial sites, from their histological mimics [30,38,39,[42][43][44][45][46] . Although rare, it is of immense importance to recognize extra-axial skeletal and soft tissue chordomas as the treatment of this neoplasm and patient prognosis differs from that of other neoplasms, which it could be mistaken for.…”

“…An example of biocompatible structures is silica-coated nanoparticles, which can be used for gene therapy [45] . There are several studies that highlight silica and magnetic inorganic nanoparticles (such as Fe 3 O 4 and MnO 2 ) for gene delivery [46,47] . One of the main candidates that is currently investigated for gene therapy is gold nanoparticles, which are recommended for transferring nucleic acids into tumors [46] .…”

Intradural chordoma mimicking a lateral sphenoid wing meningioma: a

“…The correct diagnosis might be confirmed by immunohistochemical studies. A chordoma is immunopositive for cytokeratin, S-100, vimentin and EMA; whereas, a chordoid meningioma is positive for EMA and vimentin but mostly negative for cytokeratin and S-100 protein [13,21]. Moreover, in the majority of chordoid meningiomas, there are distinctive areas of a conventional type of meningioma.…”