title: DNA mismatch repair defects and microsatellite instability status in periocular sebaceous carcinoma.
abstract: OBJECTIVE
  To characterize mismatch repair protein expression and the role of DNA repair abnormalities in sebaceous carcinomas of the ocular adnexa.
  
  
  METHODS
  Retrospective case-series study.
  
  
  METHODS
  We reviewed 10 cases of sporadic sebaceous carcinoma and 1 case involving a patient with a family history consistent with Muir-Torre syndrome. Immunohistochemistry was used to analyze the presence of 4 mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) in these tumors. DNA was extracted from 7 of the larger tumors as well as from adjacent normal control tissue and microsatellite instability (MSI) analysis using 5 highly sensitive mononucleotides and 2 pentanucleotides was performed.
  
  
  RESULTS
  All 10 sporadic periocular sebaceous carcinomas maintained strong staining of the 4 mismatch repair genes, while tumor from the patient with Muir-Torre syndrome showed loss of staining for the mismatch repair genes MSH2 and MSH6. MSI testing of 7 tumors identified no changes in sporadic cases and yielded results supporting presence of repeat sequence instability in the Muir-Torre-associated case.
  
  
  CONCLUSIONS
  Sporadic sebaceous carcinoma of the ocular adnexa is not commonly associated with a loss of mismatch repair genes or microsatellite instability.
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Anand
authors: A
authors: Rajan Kd
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Christopher
authors: C
authors: Burris
authors: Department of Ophthalmology, Johns Hopkins University School of Medicine Wilmer Eye Institute, Baltimore, Maryland.
authors: Nicholas
authors: N
authors: Iliff
authors: Department of Ophthalmology, Johns Hopkins University School of Medicine Wilmer Eye Institute, Baltimore, Maryland.
authors: Michael
authors: M
authors: Grant
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: James R
authors: JR
authors: Eshleman
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Ophthalmology, Johns Hopkins University School of Medicine Wilmer Eye Institute, Baltimore, Maryland. Electronic address: ceberha@jhmi.edu.
authors: Charles G
authors: CG
authors: Eberhart
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D018266:Adenocarcinoma, Sebaceous / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D053843:DNA Mismatch Repair / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005142:Eyelid Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D012626:Sebaceous Gland Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D000251:Adenosine Triphosphatases; C094934:PMS2 protein, human; C497172:MSH2 protein, human; D000070976:Mismatch Repair Endonuclease PMS2; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes