Role of Immunohistochemistry in the Identification of Supratentorial C11ORF95-RELA Fused Ependymoma in Routine Neuropathology

Marco Gessi, Marzia Giagnacovo, Piergiorgio Modena, Grazia Elefante, Francesca Gianno, Francesca R Buttarelli, Antonietta Arcella, Vittoria Donofrio, Francesca Diomedi Camassei, Paolo Nozza, Isabella Morra, Maura Massimino, Bianca Pollo, Felice Giangaspero, Manila Antonelli

Research output: Contribution to journalArticle

Abstract

Ependymomas (EPs) are tumors of the brain and spinal cord constituting ∼10% of the childhood central nervous system neoplasms and about 30% in children aged <3 years. Their anatomic distribution varies according to the age, with those arising in the supratentorial (ST) compartment, spinal cord being more common in older children and adults, and those at the infratentorial location are more common and occurring more frequently in infants and children. Recently, molecular classification of EP subgroups has been proposed and a supratentorial ependymoma subgroup characterized by RELA-fusion genes (ST-EP-RELA) has been established. It would be useful to define a standardized, robust method for the diagnosis of these relevant fusion genes. We used real-time polymerase chain reaction, conventional real-time polymerase chain reaction, and Sanger sequencing to characterize RELA fusion status in formalin-fixed paraffin-embedded samples from 42 ST-EPs (12 adults and 30 pediatric). We tested p65/RELA and L1CAM protein immunohistochemistry for their ability to predict RELA-fusion status. We reviewed clinical data to assess significant associations in this anatomic subgroup. Of the 42 patients, we identified RELA-fusion genes in 17 cases. L1CAM immunostaining displayed 94% sensitivity, 76% specificity, 73% positive predictive value (PPV), 95% negative predictive value (NPV). The p65/RELA immunostaining displayed 100% sensitivity, 92% specificity, 89.5% PPV, 100% NPV. Concordant double immunostaining improves PPV to 92.5% and maintains 100% NPV. Immunohistochemistry using both p65/RELA and L1CAM antibodies is valuable for ST-EP-RELA diagnosis: the negativity with both antibodies consistently predicts the absence of RELA fusions, whereas verification of fusion transcripts by molecular analyses is warranted only in single-positive or double-positive staining cases.

Original languageEnglish
Pages (from-to)56-63
Number of pages8
JournalAmerican Journal of Surgical Pathology
Volume43
Issue number1
DOIs
Publication statusPublished - Jan 2019

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Ependymoma
Immunohistochemistry
Neural Cell Adhesion Molecule L1
Gene Fusion
Real-Time Polymerase Chain Reaction
Spinal Cord Neoplasms
Sensitivity and Specificity
Central Nervous System Neoplasms
Antibodies
Paraffin
Formaldehyde
Neuropathology
Spinal Cord
Pediatrics
Staining and Labeling
Proteins

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Role of Immunohistochemistry in the Identification of Supratentorial C11ORF95-RELA Fused Ependymoma in Routine Neuropathology. / Gessi, Marco; Giagnacovo, Marzia; Modena, Piergiorgio; Elefante, Grazia; Gianno, Francesca; Buttarelli, Francesca R; Arcella, Antonietta; Donofrio, Vittoria; Diomedi Camassei, Francesca; Nozza, Paolo; Morra, Isabella; Massimino, Maura; Pollo, Bianca; Giangaspero, Felice; Antonelli, Manila.

In: American Journal of Surgical Pathology, Vol. 43, No. 1, 01.2019, p. 56-63.

Research output: Contribution to journalArticle

Gessi, Marco ; Giagnacovo, Marzia ; Modena, Piergiorgio ; Elefante, Grazia ; Gianno, Francesca ; Buttarelli, Francesca R ; Arcella, Antonietta ; Donofrio, Vittoria ; Diomedi Camassei, Francesca ; Nozza, Paolo ; Morra, Isabella ; Massimino, Maura ; Pollo, Bianca ; Giangaspero, Felice ; Antonelli, Manila. / Role of Immunohistochemistry in the Identification of Supratentorial C11ORF95-RELA Fused Ependymoma in Routine Neuropathology. In: American Journal of Surgical Pathology. 2019 ; Vol. 43, No. 1. pp. 56-63.
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abstract = "Ependymomas (EPs) are tumors of the brain and spinal cord constituting ∼10{\%} of the childhood central nervous system neoplasms and about 30{\%} in children aged <3 years. Their anatomic distribution varies according to the age, with those arising in the supratentorial (ST) compartment, spinal cord being more common in older children and adults, and those at the infratentorial location are more common and occurring more frequently in infants and children. Recently, molecular classification of EP subgroups has been proposed and a supratentorial ependymoma subgroup characterized by RELA-fusion genes (ST-EP-RELA) has been established. It would be useful to define a standardized, robust method for the diagnosis of these relevant fusion genes. We used real-time polymerase chain reaction, conventional real-time polymerase chain reaction, and Sanger sequencing to characterize RELA fusion status in formalin-fixed paraffin-embedded samples from 42 ST-EPs (12 adults and 30 pediatric). We tested p65/RELA and L1CAM protein immunohistochemistry for their ability to predict RELA-fusion status. We reviewed clinical data to assess significant associations in this anatomic subgroup. Of the 42 patients, we identified RELA-fusion genes in 17 cases. L1CAM immunostaining displayed 94{\%} sensitivity, 76{\%} specificity, 73{\%} positive predictive value (PPV), 95{\%} negative predictive value (NPV). The p65/RELA immunostaining displayed 100{\%} sensitivity, 92{\%} specificity, 89.5{\%} PPV, 100{\%} NPV. Concordant double immunostaining improves PPV to 92.5{\%} and maintains 100{\%} NPV. Immunohistochemistry using both p65/RELA and L1CAM antibodies is valuable for ST-EP-RELA diagnosis: the negativity with both antibodies consistently predicts the absence of RELA fusions, whereas verification of fusion transcripts by molecular analyses is warranted only in single-positive or double-positive staining cases.",
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T1 - Role of Immunohistochemistry in the Identification of Supratentorial C11ORF95-RELA Fused Ependymoma in Routine Neuropathology

AU - Gessi, Marco

AU - Giagnacovo, Marzia

AU - Modena, Piergiorgio

AU - Elefante, Grazia

AU - Gianno, Francesca

AU - Buttarelli, Francesca R

AU - Arcella, Antonietta

AU - Donofrio, Vittoria

AU - Diomedi Camassei, Francesca

AU - Nozza, Paolo

AU - Morra, Isabella

AU - Massimino, Maura

AU - Pollo, Bianca

AU - Giangaspero, Felice

AU - Antonelli, Manila

PY - 2019/1

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N2 - Ependymomas (EPs) are tumors of the brain and spinal cord constituting ∼10% of the childhood central nervous system neoplasms and about 30% in children aged <3 years. Their anatomic distribution varies according to the age, with those arising in the supratentorial (ST) compartment, spinal cord being more common in older children and adults, and those at the infratentorial location are more common and occurring more frequently in infants and children. Recently, molecular classification of EP subgroups has been proposed and a supratentorial ependymoma subgroup characterized by RELA-fusion genes (ST-EP-RELA) has been established. It would be useful to define a standardized, robust method for the diagnosis of these relevant fusion genes. We used real-time polymerase chain reaction, conventional real-time polymerase chain reaction, and Sanger sequencing to characterize RELA fusion status in formalin-fixed paraffin-embedded samples from 42 ST-EPs (12 adults and 30 pediatric). We tested p65/RELA and L1CAM protein immunohistochemistry for their ability to predict RELA-fusion status. We reviewed clinical data to assess significant associations in this anatomic subgroup. Of the 42 patients, we identified RELA-fusion genes in 17 cases. L1CAM immunostaining displayed 94% sensitivity, 76% specificity, 73% positive predictive value (PPV), 95% negative predictive value (NPV). The p65/RELA immunostaining displayed 100% sensitivity, 92% specificity, 89.5% PPV, 100% NPV. Concordant double immunostaining improves PPV to 92.5% and maintains 100% NPV. Immunohistochemistry using both p65/RELA and L1CAM antibodies is valuable for ST-EP-RELA diagnosis: the negativity with both antibodies consistently predicts the absence of RELA fusions, whereas verification of fusion transcripts by molecular analyses is warranted only in single-positive or double-positive staining cases.

AB - Ependymomas (EPs) are tumors of the brain and spinal cord constituting ∼10% of the childhood central nervous system neoplasms and about 30% in children aged <3 years. Their anatomic distribution varies according to the age, with those arising in the supratentorial (ST) compartment, spinal cord being more common in older children and adults, and those at the infratentorial location are more common and occurring more frequently in infants and children. Recently, molecular classification of EP subgroups has been proposed and a supratentorial ependymoma subgroup characterized by RELA-fusion genes (ST-EP-RELA) has been established. It would be useful to define a standardized, robust method for the diagnosis of these relevant fusion genes. We used real-time polymerase chain reaction, conventional real-time polymerase chain reaction, and Sanger sequencing to characterize RELA fusion status in formalin-fixed paraffin-embedded samples from 42 ST-EPs (12 adults and 30 pediatric). We tested p65/RELA and L1CAM protein immunohistochemistry for their ability to predict RELA-fusion status. We reviewed clinical data to assess significant associations in this anatomic subgroup. Of the 42 patients, we identified RELA-fusion genes in 17 cases. L1CAM immunostaining displayed 94% sensitivity, 76% specificity, 73% positive predictive value (PPV), 95% negative predictive value (NPV). The p65/RELA immunostaining displayed 100% sensitivity, 92% specificity, 89.5% PPV, 100% NPV. Concordant double immunostaining improves PPV to 92.5% and maintains 100% NPV. Immunohistochemistry using both p65/RELA and L1CAM antibodies is valuable for ST-EP-RELA diagnosis: the negativity with both antibodies consistently predicts the absence of RELA fusions, whereas verification of fusion transcripts by molecular analyses is warranted only in single-positive or double-positive staining cases.

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DO - 10.1097/PAS.0000000000000979

M3 - Article

VL - 43

SP - 56

EP - 63

JO - American Journal of Surgical Pathology

JF - American Journal of Surgical Pathology

SN - 0147-5185

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ER -