Acquired Periungual Fibrokeratoma: An Atypical Case Covering the Entire Thumb Nail / 대한피부과학회지

ABSTRACT

Acquired periungual fibrokeratoma, first reported by Cahn in 1977, is a rare, benign fibrous tissue tumor located in the periungual area. The pathophysiology of acquired periungual fibrokeratoma is unknown. In general, trauma is often thought to be a predisposing factor. A 57-year-old woman presented with a 15-year-old asymptomatic, solitary, 1.8×1.5-cm, skin-colored mass on the Lt. thumb nail. The patient reported that they had been wounded on the nail root and the mass had since grown. For differential diagnosis and to determine the extent of the tumor, MRI of the finger was performed. Radiologic presentation showed a non-enhancing T2 low, T1 low signal mass above the nail plate. Histopathologic examination demonstrated a dome-shaped tumor consisting of thick dermal collagen bundles with increased capillaries. Through clinical, radiological, and histopathologic findings, we diagnosed the tumor as acquired periungual fibrokeratoma, and the lesion was removed through complete excision. Herein, we present a rare case of acquired fibrokeratoma covering whole thumb. The specific diagnosis was aided by MRI more through the acquisition of more accurate information about the location and signal characteristics that reflect underlying pathological features.