title: False-Negative Cases on Confocal Microscopy Examination: A Retrospective Evaluation and Critical Reappraisal.
abstract: BACKGROUND
  Confocal microscopy is a second-level examination for dermoscopically equivocal melanocytic lesions. However, the number of false-negative cases on confocal microscopy and the scenarios in which confocal microscopy may fail have not been fully elucidated.
  
  
  OBJECTIVE
  To calculate the percentage of false-negative melanomas upon reflectance confocal microscopy examination in a large series of cases.
  
  
  METHODS
  A retrospective analysis on 201 melanomas, evaluated for dermoscopic/confocal criteria of melanoma, was carried out.
  
  
  RESULTS
  Twenty-three melanomas out of 201 cases (11.4%) revealed a low 7-point checklist score. On confocal examination, 22 out of 23 lesions have been diagnosed correctly as melanomas. Only 1 lesion did not display melanoma features, neither upon dermoscopy nor upon confocal microscopy examination. Seven lesions out of 201 cases (3.5%) were judged as negative on confocal examination, even if 6 of them were diagnosed as melanomas by clinical and/or dermoscopic evaluation. After histopathological revision, these cases were grouped into 5 categories: (1) amelanotic melanoma (n = 1), (2) hyperkeratotic melanomas (n = 2), (3) lentiginous melanomas (n = 2), (4) melanoma with small pagetoid cells (n = 1), (5) spitzoid melanoma (n = 1).
  
  
  CONCLUSIONS
  Confocal and dermoscopic examination, along with patient-related information and clinical history, can lead to an optimal patient management.
authors: Dermatology Unit, Catholic University, Rome, Italy.
authors: Valeria
authors: V
authors: Coco
authors: Francesca
authors: F
authors: Farnetani
authors: Anna Maria
authors: AM
authors: Cesinaro
authors: Silvana
authors: S
authors: Ciardo
authors: Giuseppe
authors: G
authors: Argenziano
authors: Ketty
authors: K
authors: Peris
authors: Giovanni
authors: G
authors: Pellacani
authors: Caterina
authors: C
authors: Longo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D046169:Dermoscopy; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology; D018328:Melanoma, Amelanotic / Q000000981:diagnostic imaging / Q000473:pathology; D018613:Microscopy, Confocal; D008875:Middle Aged; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology