Loss of CTNNB1 exon 3 in sclerosing angiomatoid nodular transformation of the spleen


Uzun S., Ozcan O., Isik A., Saglam A. , Gedikoglu G., Demiroz A. S. , ...Daha Fazla

VIRCHOWS ARCHIV, 2021 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası:
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1007/s00428-021-03064-y
  • Dergi Adı: VIRCHOWS ARCHIV

Özet

Sclerosing angiomatoid nodular transformation (SANT) is a rare vascular lesion of the spleen. Although several hypotheses have been suggested, the etiopathogenesis of SANT remains unknown. It is also unclear whether SANT is a reactive or a neoplastic lesion. Since CTNNB1 (beta-catenin gene) exon 3 mutations were frequently detected in some rare fibrovascular lesions, we aimed to investigate the presence of oncogenic CTNNB1 mutations in SANT cases. For this purpose, 7 cases of SANT with typical histopathological features were retrieved. First, the presence of CTNNB1 exon 3 alterations was examined with a recently described immunohistochemistry-based method. Then, the findings were confirmed with polymerase chain reaction (PCR), reverse transcription PCR (RT-PCR), and Sanger sequencing. In all cases, immunochemistry of beta-catenin gave a staining pattern that was suggestive of exon 3 alteration; however, no missense mutations were found in any case at the CTNNB1 exon 3 hotspot region. Subsequently, we screened for large interstitial deletions of CTNNB1 exon 3 which revealed short PCR products in three cases. Sequencing confirmed that these cases had large interstitial deletions, resulting in loss of the entire exon 3 of CTNNB1. In the remaining four cases, loss of exon 3 was documented at the cDNA level, although genomic deletion was not identified. These results demonstrate that loss of CTNNB1 exon 3 and stabilization of beta-catenin with activation of Wnt signaling pathway might have a significant role in the pathogenesis of SANT. Through this study, we provided important evidence for the neoplastic nature and pathogenesis of this disorder.