Onychomatricoma: A Rare Tumor of Nail Matrix

Abstract

Onychomatricoma is a rare tumor of the nail matrix. Until now, few cases of onychomatricoma have been reported in the literature. Immunohistochemically, CD10, a marker of the onychodermis, is expressed in the stroma of the onychomatricoma. In the present case, a 27-year-old woman presented with an 8-year history of a yellowish, thickened, and overcurved nail plate of the right index finger, mimicking onychomycosis. She had been treated for 4 years with antifungal agents by general physicians, without improvement. The nail was surgically removed, and the tumor at the nail matrix was excised. The nail plate continued to grow in the 2 months after the excision. This is a case of onychomatricoma in South Korea, which was initially misdiagnosed as onychomycosis. In addition, we present a review of the literature regarding clinical, sonographic, and histological features, differential diagnoses, and treatment of onychomatricoma.

Imaging technique for the diagnosis of onychomatricoma

“…In the other four cases, longitudinal oblique US image of the nail evidenced hypoechogenic solid areas affecting the nail matrix (under the proximal nail fold) with hyperechogenic linear dots corresponding to the finger‐like tumoral projections deforming the plate. Analysis with colour Doppler US showed a non‐specific hypovascular pattern . In our experience, axial images of the tumoral digitations can be obtained at the free edge margin of the nail plate (Fig.…”

“…Ultrasonography (US) is an imaging technique that uses reflected pulses of high‐frequency sound waves and can be used to assess soft tissues. Six onychomatricomas were evaluated by high‐resolution variable‐frequency US . In two cases, ultrasound imaging failed to provide diagnostic evidence of the disease .…”

Magnetic Resonance Imaging in the Diagnosis of Onychomatricoma: A Case Report

“…Dermoscopy typically shows perforations in the distal portion of the nail plate, haemorrhagic striae, and white longitudinal grooves corresponding to the nail plate channels [11, 12]. …”

CD10 and the nail

“…CD10 is expressed in onychomatricoma and may also be used as a marker to define excision specimens of the nail in ingrown nail surgery. 10,11 Patchy weak expression of CD10 and CD34 was seen in a rare case of unguioblastic matrix fibroma. 12 While the concept of onychodermis was rejected, at least for adult nails, by Perrin on the basis that he found less consistent CD10 marking and focal CD34 expression, 13 others assume that the onychodermis might play a role in the production and adhesion of the hard keratins of the nail plate.…”

“…Although the enzyme function of CD10 is clearly defined and many cells and tissues are identified that contain CD10, it is yet unknown what CD10 exactly does in the nail matrix and bed connective tissue. CD10 is expressed in onychomatricoma and may also be used as a marker to define excision specimens of the nail in ingrown nail surgery . Patchy weak expression of CD10 and CD34 was seen in a rare case of unguioblastic matrix fibroma .…”