Utility of immunohistochemical investigation of SDHB and molecular genetic analysis of SDH genes in the differential diagnosis of mesenchymal tumors of GIT
- Autores: M. Dubova, M. Sedivcova, Michal Michal, B. Kokoskova, A. Ryska, D. Smid, O. Daum
- Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 30, Nº. 2, 2015, págs. 223-232
- Idioma: inglés
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Resumen
Loss of expression of beta subunit of succinate dehydrogenase (SDHB) was proved to be present in a subgroup of KIT/PDGFRA wt gastro-intestinal stromal tumors (GISTs). To evaluate possible diagnostic utility of SDHB immunohistochemistry in the differential diagnostics of mesenchymal tumors of gastrointestinal tract (GIT), 11 cases of KIT/PDGFRA wt GISTs, 12 gastric schwannomas (GSs), 20 solitary fibrous tumors (SFTs), 4 leiomyomas (LMs), 16 leiomyosarcomas (LMSs), 5 synovial sarcomas (SSs), 3 endometrioid stromal sarcomas (ESSs), and 1 ileal inflammatory myofibroblastic tumor (IMT) were investigated for SDHB immunoexpression together with molecular genetic analysis of genes encoding succinate dehydrogenase (SDH). Three recent cases of KIT/PDGFRA mutant GISTs were used as controls. Among the 11 KIT/PDGFRA wt GISTs, 6 expressed SDHB, 1 of them harboring a sequence change of SDHD. All SDHB-negative cases were SDHB-D wt. In 1 of the control GIST cases molecular genetic analysis revealed an SDHD sequence change in addition to a mutation in KIT exon 11. No SFT was truly SDHB-negative, but in 2 of them the staining was impossible to analyze. Furthermore, 1 SFT carried an SDHB and another 1 SDHD sequence change. All GSs, LMs, LMSs, SSs, ESSs, and IMT were SDHB-positive or non-analyzable, and SDHB-D wt. Additional factors may play a role in regulating expression of SDHB. Furthermore, SDHB immuno-histochemistry alone may be misleading in excluding tumors other than GIST (especially SFT) in the differential diagnosis of KIT/PDGFRA wt mesenchymal tumors of GIT
