title: Fluorescence in situ hybridisation (FISH) in histologically challenging conjunctival melanocytic lesions.
abstract: BACKGROUND
  Even in experienced hands, the classification of some melanocytic lesions of the conjunctiva remains challenging. In skin pathology, the recent application of fluorescence in situ hybridisation (FISH) has been demonstrated to be of use for the analysis and diagnosis of ambiguous melanocytic neoplasms of the skin. This study set out to evaluate this method on seven prospective conjunctival cases that were histologically equivocal.
  
  
  METHODS
  18 unequivocal retrospective melanocytic controls were exposed to FISH. Commercially available probes assessing copy numbers of RREB1 (6p25), MYB (6q23) and CCND1 (11q13) genes compared with CEP6 (a chromosome six centromeric reference point) were used. After control verification, seven prospective, equivocal cases were identified and exposed to FISH.
  
  
  RESULTS
  There was complete correlation between FISH result and the control section histopathology report. Control cases of melanoma cases were all positive for FISH and control benign lesions were negative. Of the seven equivocal cases, five were positive and classed as invasive melanoma or melanoma-in situ, one was negative and one tetraploid, classed as negative (these last two cases were classed as naevi with careful clinical observation).
  
  
  CONCLUSIONS
  FISH is very useful in classifying equivocal conjunctival melanocytic lesions, especially those with atypical junctional activity and naevoid melanocytic proliferations of the conjunctiva.
authors.affiliation: National Specialist Ophthalmic Pathology Service, Department of Histopathology, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK. hardeep.mudhar@sth.nhs.uk
authors.forename: Hardeep Singh
authors.initials: HS
authors.lastname: Mudhar
authors.forename: Kath
authors.initials: K
authors.lastname: Smith
authors.forename: Polly
authors.initials: P
authors.lastname: Talley
authors.forename: Abigail
authors.initials: A
authors.lastname: Whitworth
authors.forename: Neil
authors.initials: N
authors.lastname: Atkey
authors.forename: Ian G
authors.initials: IG
authors.lastname: Rennie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003230:Conjunctival Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000235:genetics; D019938:Cyclin D1 / Q000235:genetics; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008545:Melanoma / Q000145:classification / Q000175:diagnosis* / Q000235:genetics; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D009508:Nevus, Pigmented / Q000145:classification / Q000175:diagnosis* / Q000235:genetics; D011446:Prospective Studies; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics; D012189:Retrospective Studies; D014157:Transcription Factors / Q000235:genetics; D055815:Young Adult
chemical_list: C530104:CCND1 protein, human; D015342:DNA Probes; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D020598:Proto-Oncogene Proteins c-myb; C101743:RREB1 protein, human; D014157:Transcription Factors; D019938:Cyclin D1