BACKGROUND. Onychomntricoma is a rave benign tumor originating in the
nail matrix. Only eight cases have been reported until now. OBJECTIVE.
The clinical and histopathological features of this recently reported
tumor will be described and its differential diagnoses outlined. A ty
pical case of onychomatricoma is described in a 62-year-old white man.
RESULTS. Clinically, onychomatricoma is characterized by: 1) a yellow
ish discoloration of a longitudinal segment of the nail plate with sma
ll splinter hemorrhages within the proximal portion of the nail; 2) a
thickening with increased transversal curvature of the involved nail p
late positively corresponding with the yellow discoloration; and 3) a
matrix tumor consisting of multiple fine filiform projections that ext
end into the-thickened nail plate. The treatment of onychomatricoma is
complete excision of the tumor. CONCLUSION. Onychomatricoma is a new
entity with clinical and histopathological features that are character
istic enongh to make the correct diagnosis.