Spinal cord glioneuronal tumor with neuropil-like islands with 1p/19q deletion in an adult with low-grade cerebral oligodendroglioma

Abstract

Glioneuronal tumor with neuropil-like islands (GTNI) is considered a rare variant of astrocytoma, characterized by discrete aggregates of cells expressing neuronal markers that punctuate a GFAP-positive glial background. Of the 24 published GTNI cases, only two occurred in adult spinal cords; none occurred concurrent with another CNS tumor; and none of those tested exhibited the 1p/19q deletion typical of oligodendroglioma. A 48-year-old man without significant past medical history was diagnosed with a WHO grade II oligodendroglioma by stereotactic biopsy of a lesion discovered after the patient suffered a generalized tonic-clonic seizure. By FISH analysis, this tumor exhibited the 1p/19q deletion present in up to 80% of oligodendrogliomas. The patient received 14 monthly cycles of temozolomide, and his cerebral tumor had a minor response. When the patient subsequently reported progressive paresthesias of his lower extremities, an MRI revealed an enhancing, cystic tumor of the thoracic spinal cord that was diagnosed as GTNI by histological analysis. By FISH analysis, this lesion exhibited the same 1p/19q deletion present in the concurrent cerebral oligodendroglioma. This case of a spinal cord GTNI with 1p/19q deletions constitutes the third report of a spinal cord GTNI in an adult patient; the first report of a GTNI in an individual with a separate CNS neoplasm; and the first report of a GTNI with 1p/19q deletions. This case establishes a potential genetic kinship between GTNI and oligodendroglioma that warrants further investigation.

Glioneuronal Tumor with Neuropil-Like Islands: Clinical, Morphologic, Immunohistochemical, and Molecular Features of Three Pediatric Cases

“…Consequently, we confirm that the glial component of glioneuronal tumor with neuropil-like islands may also have an ependymal nature. With reference to the 1p/19q deletions, it is intriguing to note that almost all of the glioneuronal tumors with neuropil-like islands carrying one or both of these deletions have a spinal localization (3 of the 4 cases previously reported in the literature and 2 of our cases) [7]. These data suggest that this genetic characteristic is typical of spinal glioneuronal tumors with neuropil-like islands.…”

“…We must remember that Gessi and Rodriguez, even in their descriptions of these tumors (''ependymoma with neuropil-like islands'' and ''ependymomas with neuronal differentiation,'' respectively), stressed the ependymal nature of the glial component. On the other hand, the oligodendroglial differentiation could also be more than just anecdotal, because at least 2 reported tumors that carried the molecular traits of oligodendrogliomas (deletion of both 1p and 19q) have been described [6,7,15,18].…”

“…However, subsequent articles describing a total of 25 cases have shown that this tumor may also affect children and may originate in the spinal cord. Moreover, it was suggested, at least in some cases, that the glial component of this tumor may not be astrocytic in its nature [2,3,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Spinal Cord Glioneuronal Tumor with Rosetted Neuropil-Like Islands in Pediatric Age Group

“…Perry et al claimed that glioneuronal tumors were oligodendroglial tumors showing neurocytic differentiation [ 12 ]. Oligodendrocyte-like cells having perinuclear halo and 1p 19q deletion in a small number of cases are histologic and molecular genetic findings, respectively, supporting Perry and his colleagues' claim [ 12 , 13 ]. However, it has been noted that in some cases 1p 19q deletion could not be detected [ 8 ].…”

Disseminated Glioneuronal Tumor with Neuropil-Like Islands of the Spinal Cord: A Distinctive Entity

“…With the exception of three spinal cord lesions (6,13,15), all tumors in adult patients have been intracranial (5,8,12). In contrast, only five cases of spinal GTNI have been reported in pediatric patients (4,11,16).…”