A case of subungual squamous cell carcinoma treated with local resection and adjunctive ALA-PDT

The early symptoms of subungual squamous cell carcinoma are often nonspecific, leading to frequent misdiagnosis as conditions such as paronychia or subungual warts. Treatment options for this malignancy remain relatively limited in clinical practice. This study presents the case of a 74-year-old male with subungual squamous cell carcinoma who achieved significant improvement following photodynamic therapy. The patient had experienced pain and exudation of the big toe for over six months. Initially diagnosed with paronychia, he was treated with oral clarithromycin tablets (0.5 g daily) for half a month, which yielded no notable improvement. Subsequent intermittent application of iodophor and mupirocin ointment also resulted in poor clinical outcomes. A pathological biopsy was then performed, leading to a diagnosis of subungual squamous cell carcinoma. The tumor tissues were removed by local resection, followed by three sessions of photodynamic therapy administered at 10-day intervals. All suspected lesions were excised via local resection, with preservation of the nail bed and nail fold. A 20 % 5-aminolevulinic acid (ALA) solution (118 mg, Shanghai Fudan-Zhangjiang Bio-Pharmaceutical Co., Ltd) was topically applied to the entire nail bed and nail fold, occluded with aluminum foil to block light, and incubated for 3 h. After removal of the covering, the area was irradiated with 635-nm red light at 100 mW/cm² and 120 J/cm² for 20 min (Kernel Medical Equipment Co., Ltd). Prior to treatment, the patient took 200 mg ibuprofen orally for analgesia. During the eight-month follow-up period, no recurrence was observed. It is worth noting that due to the patient's history of severe onychomycosis, some residual fungal nail changes remained visible after recovery.