Blue nevus

Melanocytic nevuses are now in the focus of attention because they are to be differentiatedfrom cutaneous melanoma. One of these tumors, requiring the attention of dermatologists and oncologists, is the blue nevus with its two clinical morphological forms: common blue nevus and cellular one. It is assumed that blue nevus is a benign melanocytic formation, its color depending on the depth of melanin deposion in the derma and the resultant optical effect. Histological studies of a common blue nevus show melanin-containing large granules, located in the axonal and spindle cells, while hourglass-shaped cellular blue nevus is formed by spindle cells, with pigmented melanocytes with long processes at the periphery. This pigmented formation is rare and is more incident in childhood. Cellular blue nevus is an object of special attention of dermato-oncologists. Cases with cutaneous melanoma simulating the clinical pathomorphological manifestations of blue nevus have been described; these facts necessitate differential diagnosis between these tumors, which should be carried out by specialists in dermatooncology. Melanoma is hazardous because of its aggressive course and metastases and because it is liable to “mimic” the blue nevus and even its cell structures. A clinical observation of blue nevus is presented.

blue nevus, melanoma, dermatoscopy, differential diagnosis