Onychomatricoma: a case report with literature review

Onychomatricoma with Onychomycosis: A Case Report and Review of the Literature

Onychomatricoma is a primary benign neoplasm of the nail matrix. Currently, a limited number of cases have been reported, so it is still considered a rare neoplasia. However, it is debatable if this condition is underdiagnosed and underreported. Onychomycosis is an important differential diagnosis of onychomatricoma, and sometimes, both these conditions may even coexist in the same nail. As the tumor grows, tissue microenvironment is more vulnerable to dermatophytes. Probably, the altered keratin appears to be susceptible to fungal invasion. Careful clinical assessment and dermoscopic evaluation help nailing the diagnosis. Usually, total nail avulsion is the preferred therapeutic approach when they coexist. Herein, we present a case of a middle-aged woman with onychomycosis and onychomatricoma affecting a single fingernail. The proposed therapy was oral terbinafine for 6 months followed by a conservative surgery. There were dramatic changes in dermoscopic features after fungal treatment, which, to our knowledge, have not been previously reported.

Onychocytic matricoma

Onychocytic matricoma is a newly described tumor of the nail matrix. Clinically, it presents with localized thickening of the nail plate and melanonychia. Histologically, it represents a benign acanthoma of onychocytes. There are 8 cases reported in the literature. A 12-year-old girl presented with localized melanonychia and concurrent thickening of the nail plate restricted to the area of pigmentation affecting the right thumb, with no history of trauma or pain. We report a case of this rare tumor occurring in late childhood and provide a comprehensive review of its clinical presentation and differential diagnosis. Both clinicians and dermatopathologists should be aware of the presentation of onychocytic matricoma and include it in their scope of diagnosis of longitudinal nail bands.

Onychomatricoma: A Rare and Potentially Underreported Tumor of the Nail Matrix

Onychomatricoma is a rare benign neoplasm of the nail matrix first described by Baran and Kint in 1992. Fewer than 80 cases of onychomatricoma have been described in the literature, 15 of which were initially misdiagnosed and treated as onychomycosis. We present the case of a 66-year-old male with thickening and linear xanthonychia of the hallux nail plate secondary to an onychomatricoma misdiagnosed as onychomycosis. Following biopsy for histopathologic analysis, the lesion and proximal nail matrix were surgically excised. At 12 months post-excision, the patient remains asymptomatic without evidence of recurrence. The purpose of the present case report is to make foot and ankle surgeons more cognizant of the pathology, highlight the nonspecific clinical and radiologic findings, and emphasize the importance of interdisciplinary communication for an accurate clinicopathologic correlation and diagnosis of the lesion. Although rare, onychomatricoma should be considered in the differential diagnosis for patients presenting with onychomycosis failing to respond to antimycologic treatment. The clinical index of suspicion for onychomatricoma should increase when only a singular dystrophic nail is involved. Following diagnostic confirmation by histopathology, complete surgical excision is the treatment of choice.

Onychomycosis and Onychomatricoma

Nail dermoscopy is helpful in the differential diagnosis of nail disorders including onychomycosis and pigmented and nonpigmented nail tumors. We report two cases of onychomatricoma with concurrent onychomycosis of the same digit. In both cases, dermoscopy of the nail plate exhibited features of onychomatricoma, whereas dermoscopy of the distal free edge revealed features of onychomycosis. It is not uncommon for patients with onychomatricoma to develop coexisting onychomycosis, as channels created by the tumor render the nail plate susceptible to invasion by fungi.

Tips to diagnose uncommon nail disorders

This article reviews 6 nail disorders that, although easy to diagnose, are misdiagnosed frequently by dermatologists and general practitioners. Diagnostic clues are emphasized to familiarize readers with features that indicate the correct diagnosis. We focus on two common tumors (onychomatricoma and onychopapilloma), two rare genetic conditions that can be diagnosed owing to nail changes (Darier disease and nail patella syndrome), and two uncommon acquired disorders (the yellow nail syndrome and lichen striatus).