Atypical Teratoid/Rhabdoid Tumor (AT/RT) Arising From Ependymoma: A Type of AT/RT Secondarily Developing From Other Primary Central Nervous System Tumors

Abstract

Atypical teratoid/rhabdoid tumors (AT/RT) are rare, aggressive, embryonal brain tumors that occur most frequently in very young children; they are characterized by rhabdoid cells and loss of INI1 protein nuclear expression. Here, we report the case of a 24-year-old man with a left frontal lobe tumor that was composed mainly of rhabdoid cells showing loss of INI1 nuclear reactivity and polyphenotypic immunohistochemical expression, with a small INI1-positive component of ependymoma. Array comparative genomic hybridization separately conducted for each histologically distinct component revealed 22 shared identical copy number alterations, including loss of heterozygosity of chromosome 22q containing the INI1 locus. Furthermore, we found the C11orf95-RELA fusion gene, the genetic hallmark of supratentorial ependymomas, not only in the ependymoma component but also in the AT/RT component by fluorescence in situ hybridization analysis, suggesting that the AT/RT cells secondarily progressed from the preexisting ependymoma cells. A second genetic inactivating event in the INI1 gene was not detected in the AT/RT component. There are several reported cases of AT/RT (or INI1-negative rhabdoid tumors) arising in the setting of other primary brain tumors (gangliogliomas, pleomorphic xanthoastrocytomas, and high-grade gliomas), but the present case

Atypical Teratoid/Rhabdoid Tumor Originated From the Trigeminal Nerve in a Young Male Adult: Case Report and Review of the Literature

“…Adult-onset AT/RT can occur anywhere in the central nervous system, such as the cerebellar hemispheres, sellar region, spinal cord, pineal region, and cranial nerves (9,(13)(14)(15)(16), even secondarily developing from other primary tumors (17,18). In addition, the clinical manifestations and neuroimaging characteristics of patients often lacked specificity (19).…”

Pituitary atypical teratoid rhabdoid tumor in a patient with prolactinoma: A unique description

“…However, additional studies are needed to verify this hypothesis. Cases of ATRT arising from low‐grade tumors, including ganglioma, pleomorphic xanthoastrocytoma and ependymoma, and sharing the same molecular alterations as the originating neoplasia, have been reported. Based on these reports, we might also hypothesize that ATRT in our patient had its origin from the previous prolactin adenoma.…”

Primary intracerebral INI1-deficient rhabdoid tumor with CD34 immunopositivity in a young adult

“…In addition, the composite rhabdoid tumors most often occur in adults arising from a pre-existing low grade glioma, such as pleomorphic xanthoastrocytoma (PXA). [ 5 14 17 ] In addition to lack of morphological resemblance to PXA, we excluded glioma by negative GFAP and absence of common molecular glioma markers, such as IDH1/2 and BRAF V600E mutation. Dadone et al .…”