Onychomatricoma

Thickness of the nail plate, transverse or longitudinal overcurvature, xanthonychia, and numerous splinter hemorrhage are the four main clinical characteristics of onychomatricoma. == Causes ==

According to recent research, onychomatricoma patients may have genetic changes, such as chromosomal deletion. == Diagnosis ==

In addition to the traditional tetrad symptoms, other diagnostic techniques such dermoscopy, ultrasonography, and histological findings are also used to make the diagnosis. A radiological examination reveals no evidence of onychomatricoma-related underlying bone involvement. An ultrasonographic examination reveals poor blood flow, a hypoechogenic region corresponding to the fingerlike projections, and a hypoechoic tumoral lesion affecting the nail matrix. The diagnosis of onychomatricoma is confirmed by its unique histological characteristics. The proximal zone, which is defined by deep epithelial invaginations occupied by overlaying ungual protrusions, is situated beneath the posterior nail fold. The distal zone, corresponding to the lunula, is made up of epithelial digitations that grow from the matrix epithelium and puncture the nail plate. == Treatment ==

Onychomatricoma is treated with surgical excision. To avoid local recurrence, the tumour must be fully removed, including the normal nail matrix close to the lesion. == Epidemiology ==

As of 2016 less than 80 cases of onychomatricoma have been reported. == See also ==