Onychocytic matricoma: Report of two cases and review of literature

Abstract

Onychocytic matricoma (OCM) is a benign epithelial acanthoma derived from the nail matrix. It is a rare and relatively new disease of the nail first described in 2012, with only 14 cases published in English literature so far. Here, we reported the first two cases of OCM in Taiwan, presenting as longitudinal streaks of nail thickening with yellowish-white discoloration and various amount of splinter hemorrhages. A brief introduction of the pathological characteristics of various subtypes and clinical differential diagnoses were provided through literature review. OCM should be included among the differential diagnoses of longitudinal pachymelanonychia or xantholeucopachyonychia.

Keywords

• longitudinal pachyonychia
• melanonychia
• nail thickening
• onychocytic matricoma
• xantholeukonychia