Diagnostic accuracy of pigmented labial macules by in vivo reflectance confocal microscopy and correlation among techniques.

BACKGROUND

Pigmented labial macules (PLMs) are clinical, dermoscopic, and histopathologic challenges.

OBJECTIVE

To describe and evaluate the utility of reflectance confocal microscopy (RCM) in PLMs and to establish a correlation between dermoscopy, RCM, histopathology, and immunohistochemistry.

METHODS

Prospective study of PLMs from 4 tertiary referral dermatology centers. The study included 51 biopsy specimen-proven PLMs. Dermoscopic, RCM images, and histopathologic preparations were evaluated for malignant criteria. Diagnostic accuracy of RCM for melanoma diagnosis, RCM Lip Score previously reported, and κ values between techniques were calculated.

RESULTS

Included were 5 melanomas and 46 benign PLMs. Dermoscopically, melanomas exhibited more frequently ≥3 colors and ≥3 structures. With RCM, pagetoid spreading, epithelial disarray, continuous proliferation of atypical cells around papillae, nonhomogeneously distributed papillae, marked cellular atypia, and a higher number of dendritic cells per papillae were more frequent in melanomas. The RCM Lip Score was significantly higher in malignant lesions. Good κ values were observed in most of the evaluated features. A perfect sensitivity and specificity was obtained combining dermoscopy and RCM.

LIMITATIONS: A low number of melanomas were obtained.

CONCLUSIONS

RCM improves lip melanoma diagnosis, and the RCM Lip Score represents a useful tool for the evaluation of a PLM.