title: Sebaceous adenomas of the eyelid and Muir-Torre Syndrome.
abstract: OBJECTIVE
  Sebaceous adenomas (SAs) are rare, benign sebaceous gland tumours of the eyelid. SAs may be associated with primary internal malignancies. This association is known as Muir-Torre Syndrome (MTS). The purpose of this study was to approximate the prevalence of SAs, to determine the reliability of the clinical diagnosis of SAs and to demonstrate immunohistochemical staining of DNA mismatch repair proteins mutL homologue 1 (MLH1) and mutS homologue 2 (MSH2) for a case of MTS.
  
  
  METHODS
  We reviewed the histopathology reports from all eyelid specimens collected between 1993 and 2013 at the Henry C Witelson Ocular Pathology Laboratory to determine the proportion of SAs. For the SAs identified on histopathology, we looked at patient charts to see what diagnosis was originally suspected on clinical examination. Immunohistochemical staining for MLH1 and MSH2 was performed on all SAs to screen for MTS.
  
  
  RESULTS
  Of the 5884 eyelid specimens collected, 9 were SAs (6 women, 3 men; 42-72 years old). The diagnosis of SA was suspected clinically in only one of the nine cases based on the gross appearance of the eyelid lesion. Immunohistochemistry revealed one SA case with positive MLH1 expression and negative MSH2 expression. These findings prompted systemic work-up and this patient was diagnosed with MTS after discovery of a colon adenocarcinoma T2M0N0.
  
  
  CONCLUSIONS
  The diagnosis of eyelid SA is rare. The importance of this benign eyelid tumour stems from its association with internal malignancies in MTS. Immunohistochemical staining of mismatch repair proteins MLH1 and MSH2 is a valid and accessible strategy for investigating MTS in patients with SAs.
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Jagan
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Pablo
authors.initials: P
authors.lastname: Zoroquiain
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Vasco
authors.initials: V
authors.lastname: Bravo-Filho
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Logan
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Qutub
authors.affiliation: Henry C Witelson Ocular Pathology Laboratory, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: Miguel N
authors.initials: MN
authors.lastname: Burnier
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D018266:Adenocarcinoma, Sebaceous / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D053843:DNA Mismatch Repair; D005142:Eyelid Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D055653:Muir-Torre Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D015995:Prevalence; D015203:Reproducibility of Results
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D014408:Biomarkers, Tumor; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein
keywords: Anatomy; Eye Lids; Genetics; Pathology