title: Utility of immunohistochemical investigation of SDHB and molecular genetic analysis of SDH genes in the differential diagnosis of mesenchymal tumors of GIT.
abstract: Loss of expression of beta subunit of succinate dehydrogenase (SDHB) was proved to be present in a subgroup of KIT/PDGFRA wt gastrointestinal 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 immunohistochemistry alone may be misleading in excluding tumors other than GIST (especially SFT) in the differential diagnosis of KIT/PDGFRA wt mesenchymal tumors of GIT.
authors.affiliation: Sikl's Department of Pathology, Medical Faculty Hospital, Charles University, Plzen, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Dubova
authors.affiliation: Biopticka laborator s.r.o., Plzen, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Sedivcova
authors.affiliation: Sikl's Department of Pathology, Medical Faculty Hospital, Charles University, Plzen, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Michal
authors.affiliation: Sikl's Department of Pathology, Medical Faculty Hospital, Charles University, and Biopticka laborator s.r.o., Plzen, Czech Republic.
authors.forename: B
authors.initials: B
authors.lastname: Kokoskova
authors.affiliation: The Fingerland Department of Pathology, University Hospital, Hradec Kralove, Czech Republic.
authors.forename: A
authors.initials: A
authors.lastname: Ryska
authors.affiliation: Surgical Clinic, Medical Faculty Hospital, Charles University, Plzen, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Smid
authors.affiliation: Sikl's Department of Pathology, Medical Faculty Hospital, Charles University, and Biopticka laborator s.r.o., Plzen, Czech Republic. DAUM@fnplzen.cz.
authors.forename: O
authors.initials: O
authors.lastname: Daum
mesh_terms: D000328:Adult; D000368:Aged; D002648:Child; D004273:DNA, Neoplasm / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008648:Mesoderm / Q000473:pathology*; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D004273:DNA, Neoplasm; D013385:Succinate Dehydrogenase; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha