AUTHOR=Broggi Giuseppe , Piombino Eliana , Altieri Roberto , Romano Chiara , Certo Francesco , Barbagallo Giuseppe Maria Vincenzo , Vigneri Paolo , Condorelli Dario , Colarossi Lorenzo , Colarossi Cristina , Magro Gaetano , Tirrò Elena 

TITLE=Glioblastoma, IDH-Wild Type With FGFR3-TACC3 Fusion: When Morphology May Reliably Predict the Molecular Profile of a Tumor. A Case Report and Literature Review

JOURNAL=Frontiers in Neurology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.823015

DOI=10.3389/fneur.2022.823015

ISSN=1664-2295

ABSTRACT=<p>It has been reported that in-frame <italic>FGFR3-TACC3</italic> fusions confer to glioblastomas, <italic>IDH</italic>-wild type (GBMs, <italic>IDH</italic>wt) some unusual morphologic features, including monomorphous rounded cells with ovoid nuclei, nuclear palisading, endocrinoid network of “chicken-wire” vessels, microcalcifications and desmoplastic stroma, whose observation may predict the molecular profile of the tumor. We herein present a case of recurrent GBMs, <italic>IDH</italic>wt, exhibiting some of the above-mentioned morphological features and a molecularly-proven <italic>FGFR3-TACC3</italic> fusion. A 56-year-old man presented to our hospital for a recurrent GBM, <italic>IDH</italic>wt, surgically treated at another center. Histologically, the tumor, in addition to the conventional GBM morphology, exhibited the following peculiar morphologic features: (<xref ref-type="bibr" rid="B1">1</xref>) monomorphous neoplastic cells with rounded nuclei and scant pale cytoplasm; (<xref ref-type="bibr" rid="B2">2</xref>) thin capillary-like vessels with “chicken-wire” pattern; (<xref ref-type="bibr" rid="B3">3</xref>) nuclear palisading; (<xref ref-type="bibr" rid="B4">4</xref>) formation of vague perivascular pseudorosettes; (<xref ref-type="bibr" rid="B5">5</xref>) spindled tumor cells embedded in a loose, myxoid background. Based on this unusual morphology, molecular analyses were performed and an <italic>FGFR3</italic> exon17-<italic>TACC3</italic> exon 10 fusion was found. The present case contributes to widening the morphologic spectrum of <italic>FGFR3-TACC3</italic>-fused GBM, IDHwt and emphasizes that pathologists, in the presence of a GBM, <italic>IDH</italic>wt with unconventional morphology, should promptly search for this fusion gene.</p>