A Spitz naevus (or Spitz's nevus) is an uncommon type of mole (melanocytic naevus).
Spitz naevi are benign skin tumours. However, they may resemble malignant melanomas clinically and microscopically, so they are often excised as a precaution.
Who gets Spitz naevi?
Spitz naevi are seen most often in children; 70% of cases diagnosed during the first 20 years of life. They may also arise in adults. They are most frequently found in fair-skinned individuals (skin phototypes 1 and 2).
What are the clinical features of Spitz naevi?
A Spitz naevus is typically a dome-shaped red, reddish-brown papule. This is known as classic Spitz naevus. A darker papular or nodular type is called a pigmented Spitz naevus. The size ranges from a few millimetres to up to one or two centimetres in diameter. They usually appear on the face or limbs.
A Spitz naevus grows rapidly for a few months. After the initial growth period, if untreated, it may remain static for years. Spitz naevi may disappear spontaneously after a period of time.
What causes Spitz naevi?
A Spitz naevus is a type of melanocytic naevus, i.e., a mole composed of melanocyes – these are cells that normally produce pigment, melanin, and are responsible for skin colour.
It is not known why Spitz nevi occur.
How are Spitz naevi diagnosed?
Spitz naevi are often suspected clinically by their characteristic dome-shaped appearance and rapid growth over a few weeks to months. Dermatoscopy of a classic Spitz naevus often reveals uniform rounded structures with prominent blood vessels. Pigmented Spitz naevi may show starburst or globular pigmentation but later evolve to a homogeneous dermatoscopic pattern.
In children, they are often observed with digital dermatoscopic surveillance (imaging over time).
An atypical Spitzoid tumour or a Spitzoid tumour of uncertain malignant potential (STUMP) may be difficult to distinguish histologically from Spitzoid melanoma and is best widely excised.
What treatments are available for Spitz naevi?
Because of the difficultly in definitively predicting the outcome of Spitz naevi, especially in adults, it is generally recommended that Spitz naevi are cut out (excised). However, this is not always necessary in children, particularly if the lesions are typical in appearance.
What is the outcome for Spitz naevi?
The majority of Spitz naevi evolute (disappear) over a few years.