title: Urinary Bladder Paragangliomas: How Immunohistochemistry Can Assist to Identify Patients With SDHB Germline and Somatic Mutations.
abstract: Urinary bladder paraganglioma (paraganglioma) is a rare tumor of chromaffin cells of the sympathetic system of the urinary bladder wall. We studied 14 cases of this entity and investigated the usefulness of SDHB protein staining by immunohistochemistry (IHC) as a diagnostic tool to identify patients with bladder paragangliomas that could be associated with SDHB gene mutations, as these patients have a more aggressive disease. Eleven tumors from these patients were stained by IHC. Six of 11 tumors were negative for SDHB staining by IHC with no cytoplasmic staining in tumor cells when compared with normal tissues. Five of these 6 negative cases were confirmed to be positive for germline SDHB mutations. One case showed negative staining and no germline SDHB mutation; however, further investigation of the tumor revealed a somatic SDHB gene deletion. The remaining 5 cases showed strong cytoplasmic staining, but they were negative for the presence of SDHB mutation. They were found to be either sporadic tumors or part of von Hippel-Lindau syndrome. Staining for SDHA was positive in all cases. Our study confirms that there is very good correlation between the presence of an SDHB mutation, whether germline or sporadic, and negative SDHB IHC staining in urinary bladder paragangliomas, and this is the first study to demonstrate that somatic mutations can be recognized by IHC staining.
authors.affiliation: *Translational Surgical Pathology Section, Laboratory of Pathology, National Cancer Institute †Eunice Kennedy Shriver, National Institute of Child Health and Human Development ‡Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Alessio
authors.initials: A
authors.lastname: Giubellino
authors.forename: Karlena
authors.initials: K
authors.lastname: Lara
authors.forename: Victoria
authors.initials: V
authors.lastname: Martucci
authors.forename: Than
authors.initials: T
authors.lastname: Huynh
authors.forename: Piyush
authors.initials: P
authors.lastname: Agarwal
authors.forename: Karel
authors.initials: K
authors.lastname: Pacak
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Merino
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics*; D002648:Child; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D018095:Germ-Line Mutation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016612:Paraffin Embedding; D010236:Paraganglioma, Extra-Adrenal / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D011237:Predictive Value of Tests; D013385:Succinate Dehydrogenase / Q000235:genetics*; D016707:Tissue Fixation; D001749:Urinary Bladder Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; C108095:SDHB protein, human; D013385:Succinate Dehydrogenase