Non-invasive diagnosis of pink basal cell carcinoma: how much can we rely on dermoscopy and reflectance confocal microscopy?
BACKGROUND
Non-pigmented 'pink' cutaneous lesions in differential diagnosis with basal cell carcinoma may present a challenge for clinicians. Our objective was to determine the potential improvement of diagnostic accuracy using combined dermoscopy-reflectance confocal microscopy (RCM) image evaluation.


METHODS
Two hundred and sixty clinically equivocal 'pink' cutaneous lesions were evaluated retrospectively. Reader accuracy was tested with dermoscopy images only vs. RCM and combined dermoscopy-RCM images.


RESULTS
Out of 260 equivocal 'pink' cutaneous lesions, there were 114 basal cell carcinomas within a total of 140 malignancies that included 12 melanomas, 13 squamous cell carcinomas, and 1 other malignancy type. Dermoscopy only evaluation resulted in an overall sensitivity of 85.1% and specificity of 92.4%, resulting in a positive predictive value (PPV) of 89.8%, with 1 of 12 melanomas misdiagnosed. RCM evaluation resulted in an overall sensitivity of 85.1% and specificity of 93.8%, resulting in a PPV of 91.5%, with no melanomas misdiagnosed. Combined dermoscopy-RCM evaluation resulted in an overall sensitivity of 77.2% and specificity of 96.6%, resulting in a PPV of 94.6%.


CONCLUSIONS
The combination of dermoscopy-RCM evaluation significantly improves the accuracy and safety threshold in equivocal 'pink' cutaneous lesions in the differential diagnosis of basal cell carcinoma.
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
A M
http://orcid.org/0000-0001-5860-7532
AM
Witkowski
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.|Department of Biostatistics and Telemedicine, Jagiellonian University Medical College, Krakow, Poland.
J
J
Łudzik
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
N
N
DeCarvalho
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
S
S
Ciardo
Skin Cancer Unit Arcispedale S. Maria Nuova, IRCCS, Reggio Emilia, Italy.
C
C
Longo
Division of Dermatology, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
A
A
DiNardo
Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy.
G
G
Pellacani
D002280:Basal Cell Carcinoma / Q000000981:diagnostic imaging*; D046169:Dermoscopy / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D000069416:Intravital Microscopy / Q000379:methods*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D064847:Multimodal Imaging / Q000379:methods*; D010783:Photometry / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000000981:diagnostic imaging; D012878:Skin Neoplasms / Q000000981:diagnostic imaging*
basal cell carcinoma; dermoscopy; melanoma; reflectance confocal microscopy