Succinate dehydrogenase (SDH) and mitochondrial driven neoplasia
1Department of Anatomical Pathology and Northern Cancer Translational Research Unit, Royal North Shore Hospital, St Leonards, New South Wales, Australia. affgill@med.usyd.edu.au
Pathology
|May 1, 2012
Summary
Succinate dehydrogenase (SDH) mutations drive rare cancers. Negative SDHB staining identifies these tumors, including phaeochromocytoma, paraganglioma, GISTs, and renal carcinoma, guiding genetic testing for associated syndromes.
Area of Science:
- Biochemistry
- Oncology
- Genetics
Background:
- Mitochondrial complex 2, formed by succinate dehydrogenase (SDH) subunits (SDHA, SDHB, SDHC, SDHD), is crucial for cellular respiration.
- Germline mutations in SDH subunits are implicated in hereditary phaeochromocytoma and paraganglioma (PHEO/PGL), accounting for a significant portion of familial cases.
- A distinct subset of gastrointestinal stromal tumors (GISTs) and a newly recognized renal carcinoma type are also linked to mitochondrial complex 2 dysfunction.
Purpose of the Study:
- To investigate the role of SDH mutations in specific cancers.
- To evaluate the utility of immunohistochemical staining for SDHB as a diagnostic and triage tool for SDH-deficient tumors.
- To highlight the distinct clinical and morphological features of SDH-deficient neoplasms.
Main Methods:
- Immunohistochemistry for SDHB subunit expression.
- Analysis of genetic mutations in SDH subunits.
- Clinical and morphological characterization of patient cohorts.
Main Results:
- Negative SDHB staining effectively identifies PHEO/PGL associated with germline SDH mutations, enabling efficient genetic testing.
- SDH-deficient GISTs exhibit unique features: early onset, gastric location, multifocality, absence of KIT/PDGFRA mutations, and indolent metastatic behavior.
- Negative SDHB staining also recognizes a specific type of renal carcinoma linked to germline SDHB mutations.
Conclusions:
- Immunohistochemistry for SDHB is a valuable tool for identifying neoplasms driven by mitochondrial complex 2 dysfunction.
- This approach aids in recognizing distinct tumor subtypes and facilitates targeted genetic testing for associated hereditary cancer syndromes.
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