Lines Reticular

 Lines reticular -  Nevus, Clark Nevus, Melanoma, Dermatofibroma, Solar lentigo, Reticulated Seborrhoeic Keratosis

It is a network of interconnected brown lines creating lighter coloured “holes” in between. The background colour in benign lesions (that seen in the “holes”) is usually light tan and corresponds to the patients usual skin tone. In negative network (inverse network) the situation is reversed with lighter coloured net and darker areas in between. This latter pattern can be associated with melanoma.

Histologically the network corresponds to the pattern of the rete ridges extending down in the papillary dermis. In lesions such as benign naevi the rete ridges are elongated and there is an increased density of melanocytes both singly and in nests predominantly at the tips of the ridges. When viewed from above by the dermatoscope the “relative” increase of melanocytes down the rete ridges causes the net appearance leaving holes that are less pigmented.

The normal pigment network fades at the periphery. Normally it has an even colour and is regular and fairly uniform in thickness. The atypical network shows varying thicknesses of the net with irregular holes in areas and it ends very abruptly.

                                                                                Nevus

Clark Nevus

                                                                       Melanoma 

                                                             Dermatofibroma 

                                                                         Solar lentigo

 

                                                                 Reticulated  Seb K