title: Precise Longitudinal Tracking of Microscopic Structures in Melanocytic Nevi Using Reflectance Confocal Microscopy: A Feasibility Study.
abstract: OBJECTIVE
  Reflectance confocal microscopy (RCM), a cellular-level, in vivo imaging technique, may be potentially used for monitoring melanocytic neoplasms for microscopic stability vs changes over time.
  
  
  OBJECTIVE
  To test feasibility of using RCM to track specific microscopic structures within nevi over 1 year.
  
  
  METHODS
  This was an observational study, a review of prospectively acquired RCM images, performed at a tertiary academic medical center. Seventeen patients were enrolled from adult patients presenting to pigmented lesion clinic; from each participant, 3 confirmed benign nevi were randomly selected from the upper and lower back and from the lower extremity.
  
  
  METHODS
  Nevi underwent standardized RCM imaging at baseline and after 1 year.
  
  
  METHODS
  We tested interobserver reproducibility in recognition of tissue anchors, RCM structures that can be identified at 2 time points. We used 2 tests to measure concordance between independent readers: (1) In the multiple choice matching test (n = 43 nevi), readers were shown a tissue anchor in a baseline RCM image (≤ 1 × 1-mm field-of-view) and asked to identify the same structure in 1 of 4 equally sized RCM images obtained from the same nevus at follow-up. (2) In the annotation test (n = 29 nevi), readers were shown a tissue anchor in a follow-up RCM image (≤ 1 × 1-mm field-of-view) and asked to annotate the corresponding location of this structure in the baseline RCM mosaic image (≤ 5 × 5-mm field-of-view) from the same nevus; good agreement was defined as annotations deviant by less than 10% of the mosaic's width.
  
  
  RESULTS
  In total, 17 patients (mean age, 45 years [range, 28-70 years]; 10 [59%] were women) contributed a total of 51 nevi, of which 44 nevi (86%) were used for the study. Images from 7 nevi (14%) were suboptimal in quality. Tissue anchors were identified at both time points in all 44 nevi. Selected tissue anchors were located at a mean depth of 54.3 µm; the most commonly selected anchors (37 of 44 images [84.1%]) were dermal papillae. In the multiple choice matching test, compared with a reference reader, 2 readers correctly matched baseline to follow-up tissue anchors in 40 of 43 nevi (93%; P < .01) and 42 of 43 nevi (98%; P < .01), respectively. In the annotation test, there was good agreement between 2 readers in all 29 cases (100%); the mean deviation was 2% (range, 0%-7.5%).
  
  
  CONCLUSIONS
  Precise longitudinal tracking of microscopic structures in melanocytic nevi using RCM is feasible.
authors.affiliation: Department of Dermatology, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel2Dermatology Service, Memorial Sloan Kettering Cancer Center, New York.
authors.forename: Alon
authors.initials: A
authors.lastname: Scope
authors.affiliation: Department of Dermatology, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Limor
authors.initials: L
authors.lastname: Selinger
authors.affiliation: Skin and Cancer Associates, Plantation, Florida.
authors.forename: Margaret
authors.initials: M
authors.lastname: Oliviero
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Farnetani
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia, Italy.
authors.forename: Elvira
authors.initials: E
authors.lastname: Moscarella
authors.affiliation: Dermatology and Skin Cancer Unit, Arcispedale S. Maria Nuova-IRCCS, Reggio Emilia, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Longo
authors.affiliation: Skin and Cancer Associates, Plantation, Florida.
authors.forename: Harold S
authors.initials: HS
authors.lastname: Rabinovitz
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pellacani
mesh_terms: D000328:Adult; D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D020405:Dermis / Q000473:pathology; D005121:Extremities; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D008857:Microscopy, Interference / Q000379:methods*; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000648:ultrastructure*; D015588:Observer Variation; D011446:Prospective Studies; D012867:Skin / Q000648:ultrastructure; D012878:Skin Neoplasms / Q000648:ultrastructure*