Abstract: Subnastic squamous cell carcinoma (SCC) is rare, which is often diagnosed late or misdiagnosed, with an average delay of 62.4 months and a misdiagnosis rate of 78.9%. A 49-year-old male patient presented with rash on the lateral origin of the 5th finger of the right hand with pain for 2 years. Histologic examination showed highly differentiated squamous cell carcinoma. Skin malignant tumor resection and free flap transplantation were performed under local anesthesia. The patient recovered well and no recurrence was found in the follow-up of six months.

Key words: paronychia, subungual squamous cell carcinoma