Physicians have known for almost a century that some childhood lesions histologically diagnosed as melanomas did not show malignant behavior. After Spitz s original report of a series of patients, several attempts were made to establish objective criteria that would clearly delineate Spitz nevi and melanomas. Even today, no set of criteria can predict clinical outcome with absolute assurance. A Spitz nevus can arise de novo or in association with an existing melanocytic nevus. Spitz nevi have been described almost exclusively in fair-skinned individuals.
Some authors describe a slight female predominance.
After its appearance, the lesion tends to grow rapidly, and may reach a size of 1 cm within 6 months. Single, dome-shaped, red or pigmented papules or nodules are typical. Most lesions occur on the face or legs. The color may vary from nonpigmented through pink to orange-red. Some lesions are pigmented, especially those found on lower extremities.