Gliomas are a very rare subtype of pineal region tumours, whereas oligodendrogliomas of the pineal region are exceedingly rare, since there have been only 3 cases of anaplastic oligodedrogliomas reported this far.
We present a case of a low-grade oligodendroglioma arising in the pineal gland of a 37 year-old woman. The patient presented with diplopia associated with a cystic pineal region mass demonstrated on MRI. Total resection was performed and histological examination showed that the cystic wall consisted of tumour cells with a central nucleus a perinuclear halo and minimal pleomorphism. Immnunohistochemical analysis showed that these cells were diffusely positive for CD57, and negative for GFAP, CD10, CD99, cytokeratins, neurofilaments and synaptophysin. FISH analysis was performed in a small number of neoplastic cells, which were not exhausted after immunohistochemistry and did not reveal deletion of 1p and 19q chromosome arms. However, the diagnosis of a low grade oligodendroglioma of the pineal gland was assigned.
Although the spectrum of tumours arising in the pineal gland is broad, the reports of oligodendrogliomas confined to this location are exceedingly rare, and to the best of our knowledge there is no report of a low-grade oligodendroglioma. However, they should be added in the long list of tumours arising in the pineal gland.