title: Differential Diagnosis of Meningeal SFT-HPC and Meningioma: Which Immunohistochemical Markers Should Be Used?
abstract: Meningeal solitary fibrous tumors-hemangiopericytomas (SFT-HPC) and meningiomas can be difficult to distinguish on histologic examination. STAT6 immunohistochemistry (IHC) is a reliable diagnostic marker of SFT-HPCs. Recently, GRIA2 has also been reported to be a diagnostic marker of SFT-HPC, although no extensive data are available for meningeal SFT-HPCs yet. The aim of this study was to test their diagnostic performance in a large cohort of SFT-HPCs and meningiomas. IHC analyses for GRIA2 and STAT6 were performed on tissue microarrays containing 76 SFT-HPCs and 181 meningiomas. Results were compared with previous data with ALDH1 and CD34. Two different anti-STAT6 antibodies were tested: SC-20 polyclonal and YE361 monoclonal antibody. Ninety-six percent of meningeal SFT-HPCs but no meningioma displayed nuclear STAT6 positivity. With SC-20 antibody, concomitant cytoplasmic staining for STAT6 was observed in >50% of all cases, including meningiomas. However, using YE361 antibody, cytoplasmic staining was absent, and nuclear signal intensity was stronger leading to better interpretation of STAT6 IHC. GRIA2 was positive in 84% of SFT-HPCs and in 16% of meningiomas. STAT6 had excellent sensitivity (96%) and specificity (100%), ALDH1 and GRIA2 had same sensitivity (84%), but ALDH1 and CD34 had better specificity than GRIA2 (97% and 96% vs. 84%, respectively). For the differential diagnosis of SFT-HPCs versus meningiomas, the best diagnostic approach is to perform STAT6, followed by ALDH1 and CD34 in the case of uncommon STAT6-negative cases. Because of meningioma positivity, GRIA2 seems less useful in this indication.
authors.affiliation: *Department of Pathology and Neuropathology, Timone Hospital†INSERM, CRO2 UMR_S 911, Aix-Marseille Université (AMU)¶Department of Research and Innovation, Support Unit for Clinical Research and Economic Evaluation, Timone Hospital#EA 3279 Research Unit, Aix-Marseille Université (AMU), Marseille‡Department of Neuropathology, Pitié-Salpêtrière Hospital, Paris§Department of Neuropathology, CHU Lyon∥Department of Pathology, Wertheimer Hospital, Lyon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Macagno
authors.forename: Dominique
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: Karima
authors.initials: K
authors.lastname: Mokthari
authors.forename: Philippe
authors.initials: P
authors.lastname: Metellus
authors.forename: Anne
authors.initials: A
authors.lastname: Jouvet
authors.forename: Alexandre
authors.initials: A
authors.lastname: Vasiljevic
authors.forename: Anderson
authors.initials: A
authors.lastname: Loundou
authors.forename: Corinne
authors.initials: C
authors.lastname: Bouvier
mesh_terms: D000080924:Aldehyde Dehydrogenase 1 Family; D018952:Antigens, CD34 / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D006393:Hemangiopericytoma / Q000737:chemistry* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008577:Meningeal Neoplasms / Q000737:chemistry* / Q000473:pathology; D008579:Meningioma / Q000737:chemistry* / Q000473:pathology; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D018091:Receptors, AMPA / Q000032:analysis; D050697:Retinal Dehydrogenase / Q000032:analysis; D050800:STAT6 Transcription Factor / Q000032:analysis; D054364:Solitary Fibrous Tumors / Q000737:chemistry* / Q000473:pathology; D046888:Tissue Array Analysis
chemical_list: D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D007527:Isoenzymes; D018091:Receptors, AMPA; D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human; D000080924:Aldehyde Dehydrogenase 1 Family; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase; C104722:glutamate receptor ionotropic, AMPA 2