This case was originally published in 2018. The information provided in this case was accurate and correct at the time of initial program release. Any changes in terminology since the time of initial publication may not be reflected in this case.
A 58-year-old man was in his usual state of health until his wife noted he was developing "personality changes" including becoming "haphazard," forgetful, and falling asleep more frequently than in the past. MRI revealed a third ventricle brain mass that was T1- and T2-isointense, avidly and homogeneously enhancing, and measured 19 x 17 x 24 mm.
Whole Slide Image
The whole slide image provided is an H&E stained slide of suprasellar region.
What is the BEST diagnosis?
Rathke cleft cyst
Immunohistochemically, this lesion exhibits strong reactivity for which of the following?
The MOST common location where this lesion arises is which of the following?
Conus of spinal cord
Floor of the lateral ventricle
Discussion and Diagnosis
The tumor in this case is a chordoid glioma. Chordoid gliomas are generally found in adults and have a mean presentation age of 46 years. There is a female predominance of 2:1. Clinical symptoms generally manifest over a period of months or years and reflect the development of obstructive hydrocephalus or invasion/compression of normal structures around the third ventricle. Reported symptoms include headache, nausea, visual disturbances, ataxia, endocrine dysfunction, memory loss, and psychiatric abnormalities.
Chordoid gliomas typically range in size from 1.6 to 4 cm in greatest dimension, with a mean diameter of 2.8 cm. On imaging (Image A, Image B, and Image C), they are generally solid, round-to-ovoid, well-circumscribed masses involving the anterior third ventricle and hypothalamus. Most tumors exhibit physical continuity with the hypothalamus and some appear to have an intrinsic hypothalamic component, suggesting a potential origin for this neoplasm. Magnetic resonance imaging (MRI) of the brain generally shows tumors to be isointense on T1-weighted imaging and slightly hyperintense on T2-weighted imaging. With the administration of gadolinium, chordoid gliomas are intensely and uniformly contrast-enhancing.
Histologically, tumors show a sharp interface with adjacent nervous tissue parenchyma and focally appear encapsulated by fibrous tissue. Tumors are moderately cellular and consist of clusters and cords of oval to polygonal epithelioid cells with abundant eosinophilic cytoplasm. Tumor cells exhibit monotonous nuclei with fine chromatin and inconspicuous nucleoli (Image D and Image E). Tumor cells are characteristically embedded in a mucinous, often vacuolated and microcystic matrix. Prominent lymphoplasmacytic infiltrates are easily found, particularly at the tumor-brain parenchymal interface. Russell bodies are commonly encountered, but necrosis is not found. Mitoses are exceedingly rare, and vascularization is moderate.
Tumor cells exhibit intense and diffuse immunoreactivity for GFAP (Image F) and CD34, and show focal weak reactivity for EMA in half of cases. IHC for cytokeratin and synaptophysin is negative. Immunophenotyping of the inflammatory infiltrates reveals both B- and T-cells, and the plasma cells are polyclonal. The proliferation index is consistent with that of other low-grade gliomas, with MIB-1 labeling rates consistently lower than 2%.
The differential diagnosis of the third ventricular masses includes pituicytoma, granular cell tumor, ependymoma, pilocytic/pilomyxoid astrocytoma, chordoma, and chordoid meningioma. Pituicytomas characteristically exhibit either a fascicular or storiform pattern, and granular cell tumors exhibit CD68 reactivity, while ependymomas form perivascular rosettes and exhibit intracytoplasmic, EMA-positive ringlets. Pilocytic astrocytomas are composed of bipolar, CD34-negative, GFAP-positive fibrillary astrocytes that form biphasic loose and dense areas, and chordomas are strongly immunoreactive for cytokeratins and brachyury, while chordoid meningiomas are strongly and diffusely immunoreactive for EMA and SSTR2a.
Take Home Points
- Chordoid gliomas and chordomas may arise in similar locations. Chordomas are keratin positive while chordoid gliomas are positive for CD34 and GFAP.
- Chordoid gliomas are large, circumscribed tumors arising in the third ventricle.
- The differential diagnosis of these third ventricular masses includes pituicytoma, granular cell tumor, ependymoma, pilocytic/pilomyxoid astrocytoma, chordoma, and chordoid meningioma.
- Brat DJ, Scheithauer BW, Staugaitis SM, et al. Third ventricular chordoid glioma: a distinct clinicopathologic entity. J Neuropathol Exp Neurol. 1998;57:283-90.
- Cenacchi G, Roncaroli F, Cerasoli S, et al. Chordoid glioma of the third ventricle: an ultrastructural study of three cases with a histogenetic hypothesis. Am J Surg Pathol. 2001;25:401-5.
- Horbinski C, Dacic S, McLendon RE, et al. Chordoid glioma: a case report and molecular characterization of five cases. Brain Pathol. 2009;19:439-48.
- Pomper MG, Passe TJ, Burger PC, et al. Chordoid glioma: a neoplasm unique to the hypothalamus and anterior third ventricle. Am J Neuroradiol. 2001;22:464-9.
- What is the BEST diagnosis?
- A. Chordoid glioma
- B. Papillary craniopharyngioma
- C. Pituitary adenoma
- D. Rathke cleft cyst
- E. Teratoma
- Immunohistochemically, this lesion exhibits strong reactivity for which of the following?
- A. c-Kit
- B. CD34
- C. Chromogranin
- D. Cytokeratin
- E. Cytokeratin
- The MOST common location where this lesion arises is which of the following?
- A. Cerebellum
- B. Conus of spinal cord
- C. Cranial dura
- D. Floor of the lateral ventricle
- E. Third ventricle