ACKGROUND:Pigment network is an important dermoscopic features for melanocytic lesions but alterations in grid line thickness are also observed in melanomas.

OBJECTIVE:To investigate features of thick, thin and mixed pigment networks at dermoscopy and their respective features at ReflectanceConfocal Microscopy (RCM) for differential diagnosis, correlated with histology

METHODS: All melanocytic lesions with histological diagnosis, evaluated between January 2010 - May 2014, were enrolled and classified according to dermoscopy evaluation of the pigment network; thin, thick and mixed.

RESULTS:Thin network in melanoma was characterized by a honeycombed pattern (p<0.001), dendritic cells (p<0.001), atypical ringed pattern (p=0.035) and structureless area (p=0.012), whereas round cells (p<0.001), dendritic cells (p<0.001) and atypical meshwork pattern (<0.001) characterized thick network in melanoma. Mixed network type in melanoma shared honeycombed (p=0.049) and typical ringed patterns (p=0.045) in the thin area and round cells (p<0.001) and atypical meshwork pattern (p<0.001) in the thick area. Thin network in nevi was characterized by cobblestone (p<0.001) and typical ringed patterns (p=0.035), whereas thick network in nevi showed a typical meshwork pattern (p<0.001). Mixed nevi shared the same features and patterns, but more frequently with inflammatory infiltrate (p=0.047).

CONCLUSION:Differential diagnosis between melanocytic lesions (nevi or melanoma) in thin, thick and mixed pigment networks observed at dermoscopy can be assisted by RCM to improve diagnostic accuracy.

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PMID: 29115737 

DOI: 10.1111/jdv.14675