Onychomatricoma: Key clinical points of an unfrequented disease

Abstract

Introduction: onychomatricoma is a fibroepithelial tumor originating in the nail matrix, it is infrequent and usually presents around the fifth and sixth decades of life. Methods: we present the case of a 57-year-old male patient, without relevant past medical history, who complained of a non-painful lesion in the nail of the third finger of the right hand. Physical exam revealed longitudinal yellow chromonychia, whitish striae, and splinter hemorrhages. Onychectomy and proximal matricectomy were performed and the resected specimen was sent for histopathological study. Results: the histopathological study reported a fibroepithelial lesion, with invaginations of the epithelium and absence of the granular layer. Undulating and spindle cell cells accompanied by mast cells were observed in the stroma. Immunohistochemical staining was performed, confirming the diagnosis of onychomatricoma, micropapiliferum variant. Conclusions: due to the multiple differential diagnoses of this condition, it´s important for the dermatologist to become familiar with the clinic, dermoscopic findings and management of this entity.