Onychomatricoma Differential Diagnoses

Updated: Jan 25, 2017
  • Author: Annie Wester, MD, MS; Chief Editor: William D James, MD  more...
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DDx

Diagnostic Considerations

On the basis of current reports, onychomatricomas must be a consideration in the differential diagnosis of suspicious subungual lesions in elderly white patients, regardless of sex. Other considerations in the differential diagnosis include the following:

  • Verrucae vulgaris: This and squamous cell carcinoma variants of this can look very similar to onychomatricoma and may require biopsy to differentiate.

  • Fibrokeratomas [13] : These lack the fibroepithelial projections and cavitations of the nail plate that are seen with onychomatricomas. These may arise around the nail plate and would also have a collarette of slightly raised skin that encircles the base

  • Onycholemmal horns [14]

  • Periungual fibromas [15]

  • Bowen disease variant [16]

  • Subungual keratoacanthoma [17]

  • Yellow nail syndrome [18]

  • Onychomycosis: This does not manifest with longitudinal overcurvature.

  • Subungual melanoma: Pigmented onychomatricoma has been reported and has the potential for misdiagnosis as melanoma. Biopsy maybe required to differentiate. [19]

  • Onychocytic matricoma and malignant counterpart onychocytic carcinoma [20] : It presents with localized thickening of the nail plate. Histologically, it is a benign acanthoma of onychocytes. It is composed of a basal compartment with a varying admixture of prekeratogenous cells and keratogenous cells. Endokeratinization originating in the deep portion of the tumor and nests of prekeratogenous and keratogenous cells in concentric arrangement are characteristic features. It can be classified according to its histopathologic type (acanthotic, papillomatous, or keratogenous with retarded maturation) and pigmentation (pigmented, hypopigmented, melanocytic, or nonpigmented). The term pachymelanonychia is used in one paper to define the 2 clinical features of the tumor. Pachyonychia indicate a localized thickening of the nail plate, and melanonychia indicate its longitudinal pigmented band.