Dermoscopic and histopathologic diagnosis of equivocal melanocytic skin lesions: an interdisciplinary study on 107 cases.
BACKGROUND
Dermoscopy (dermatoscopy, epiluminescence microscopy) is increasingly employed for the preoperative detection of cutaneous melanoma; dermoscopic features of pigmented skin lesions have been previously defined using histopathology as the key to the code. In a preliminary study on 10 cases evaluated by nine dermoscopists and nine histopathologists, the authors experienced that when at least two dermoscopists disagree in evaluating a melanocytic lesion, even histopathologic consultations may give equivocal results.


METHODS
One hundred seven melanocytic skin lesions, consecutively excised because of equivocal clinical and/or dermoscopic features, were retrospectively examined by eight dermoscopists and eight histopathologists; the diagnostic interobserver agreement was calculated by means of the Schouten k statistics. After histopathologic consultations, all 107 lesions underwent unblinded dermoscopic re-evaluation in order to find which dermoscopic features had given rise to histopathologic diagnostic difficulties.


RESULTS
The interobserver ageement was good for both dermoscopy (k = 0.53) and histopathology (k = 0.74). Out of 48 cases evaluated by the dermoscopists in complete accordance, only 8 (16.7%) received at least one conflicting histopathologic diagnosis. Instead, among the remaining 59 cases with at least one disagreeing dermoscopic diagnosis, 21 (35.6%) received at least one disagreeing histopathologic diagnosis. The unblinded dermoscopic re-evaluation showed that five out of seven lesions with clear-cut regression structures were histopathologically controversial.


CONCLUSIONS
At least for selected and reasonably difficult lesions, a diagnostic discrepancy among formally trained dermoscopists seems to be predictive for a diagnostic disagreement among histopathologists. Lesions showing clear-cut regression structures are prone to give some histopathologic disagreement.
Ferrara
Gerardo
G
Pathologic Anatomy and Histology Service, G. Rummo General Hospital, Benevento, Italy.
Argenziano
Giuseppe
G
Soyer
H Peter
HP
Corona
Rosamaria
R
Sera
Francesco
F
Brunetti
Bruno
B
Cerroni
Lorenzo
L
Chimenti
Sergio
S
El Shabrawi-Caelen
Laila
L
Ferrari
Angela
A
Hofmann-Wellenhof
Rainer
R
Kaddu
Steven
S
Piccolo
Domenico
D
Scalvenzi
Massimiliano
M
Staibano
Stefania
S
Wolf
Ingrid H
IH
De Rosa
Gaetano
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003581:Cytodiagnosis / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology; D008853:Microscopy; D008875:Middle Aged; D015588:Observer Variation; D011361:Professional Competence; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology