A Spitz nevus is a benign (non-cancerous) skin mole composed of pigment-producing cells called melanocytes. These growths are uncommon, with about 1.4 cases per 100,000 people annually. They are most frequently identified in children and young adults, though they can develop at any age. The mean age for diagnosis is 22 years.
These moles most often develop on the face, neck, or legs. The cause is not fully understood, but some research suggests an association with sunburn, though a direct link has not been established. They are harmless lesions that form in the upper layers of the skin, the epidermis and dermis.
Appearance and Common Characteristics
A classic Spitz nevus presents as a small, dome-shaped papule raised from the skin’s surface. These lesions often have a distinctive pink or reddish color, as the melanocytes within the mole are inactive and not producing their usual pigment. However, their appearance can vary, with some presenting as tan, dark brown, or even black nodules.
A Spitz nevus is usually small, growing to about half an inch in diameter. A characteristic feature is its growth pattern. It often goes through a period of rapid growth over a few weeks to months, which can be alarming. Following this phase, the growth stabilizes, and the mole may shrink, flatten, or disappear over several years. While most individuals have only one, they can occasionally develop in clusters.
Distinguishing from Melanoma
The primary concern with a Spitz nevus is its visual resemblance to nodular melanoma, a dangerous form of skin cancer. This similarity can make it difficult for a dermatologist to distinguish between the benign mole and a malignant tumor by sight alone. The rapid growth and varied coloration can mimic the warning signs of melanoma, prompting further investigation.
To evaluate a suspicious lesion, a dermatologist uses a handheld magnifying scope called a dermatoscope. This tool allows for a detailed look at the patterns of pigmentation and blood vessels within the mole. A classic Spitz nevus may show uniform structures and prominent blood vessels, while a pigmented version might display a starburst or globular pattern. Because these features are not always definitive, a skin biopsy is frequently recommended for a conclusive diagnosis, which involves removing a tissue sample for examination by a pathologist.
The diagnostic challenge is complicated by “atypical Spitz nevi.” These lesions have microscopic features that are neither clearly benign nor definitively malignant, making it difficult for a pathologist to differentiate them from spitzoid melanoma. These atypical variants possess more concerning features, blurring the lines between a harmless mole and a cancerous growth.
Management and Treatment Options
Management depends on the patient’s age and the lesion’s appearance. For children with a classic-appearing mole, a period of observation may be chosen. This involves regular monitoring by a dermatologist for any changes, as many of these nevi in children are benign and may regress on their own.
Despite the possibility of observation, complete surgical excision is the most common recommendation, especially for adults or for lesions with atypical features. The primary reason for removal is to get a definitive diagnosis through pathological examination. The procedure includes removing a small margin of healthy tissue to ensure the entire lesion is gone.
Surgical removal provides diagnostic certainty and eliminates the possibility of the lesion being cancerous. For a confirmed benign Spitz nevus, the prognosis is excellent. Once removed, the concern is resolved, though regular skin checks are recommended for general health.