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Reflectance confocal microscopy diagnostic criteria reproducibly recognized among users

Certain reflectance confocal microscopy diagnostic criteria for melanoma and basal cell carcinoma were reproducibly recognized among users of the technique, according to recently published study results.

Researchers conducted a multicenter web-based study of reflectance confocal microscopy (RCM) images collected at a tertiary academic medical center in Italy. RCM images from 100 biopsy-proven lesions, including 55 melanocytic nevi, 20 melanomas, 15 basal cell carcinomas (BCCs), seven solar lentingines  or seborrheic keratosis and three actinic keratoses, were evaluated by nine dermatologists from six countries, who had various levels of RCM experience. Six evaluators were classified as experienced RCM users and three were classified recent RCM users.

To determine presence of predefined RCM descriptors, the dermatologists, masked to histopathological diagnosis, evaluated three RCM mosaic images per lesion.

Identification of RCM descriptors with fair to good interrater agreement and independent correlation with malignant vs. benign diagnosis by discriminant analysis, was the primary outcome.

Fair to good reproducibility was seen in eight RCM descriptors that had an independent association with a specific diagnosis. Melanoma was associated with the presence of pagetoid cells, atypical cells at the dermal epidermal junction and irregular epidermal architecture. Basal cell carcinoma was associated with aspecific junctional pattern, basaloid cells and ulceration. Nevi was linked to ringed junctional pattern and dermal nests.

The group of evaluators had a mean sensitivity of 88.9% and a mean specificity of 79.3%, while a sensitivity of 100% and specificity of 80% was seen in majority diagnosis. Experienced RCM users had a higher sensitivity (91%) compared with recent RMC users (84.8%); however, they had similar specificity (80% vs. 77.9%).

“The higher accuracy of majority diagnosis suggests that there is intrinsically more diagnostic information in RCM images than is currently used by individual evaluators,” the researchers concluded. — by Bruce Thiel

Disclosure: Farnetani reports no relevant financial disclosures. See the study for a full list of the other researchers’ relevant financial disclosures.