Nevus is a general term that refers of any kind of skin lesion appearing after birth. Every epidermal and dermal component has the potential to proliferate in an abnormal fashion forming a nevi.
Spitz nevus is a member of the melanocytic nevi group, which are benign collections of melanocytes in the skin. Although rare, there is theoretically a risk of transformation into melanoma.
Spitz nevus are characterized by the sudden onset and rapid growth during childhood or early adolescence. They are dome-shaped, reddish tan, firm papules that commonly occur on the face with a size typically < 1cm. Pathologists with limited pediatric experience maybe confused by the presence of epithelioid and spindle cells. Complete excisional biopsy of spitz nevus is recommended because recurrent, partially removed lesions may be misinterpreted histologically as malignant.