Multifocal Digital Squamous Cell Carcinoma With Sarcoma Differentiation: A Case Report

BACKGROUND Sarcomatoid squamous cell carcinoma is a rare and highly aggressive subtype of squamous cell carcinoma. Due to its highly invasive biological characteristics, the prognosis of sarcomatoid squamous cell carcinoma in the skin area is usually poor. CASE REPORT This study reports a rare case of a skin tumor involving a 48-year-old male patient with a diagnosis of sarcomatoid squamous cell carcinoma. The patient presented with multiple primary squamous cell carcinomas on both hands and a sarcomatoid tumor on the third finger of the right hand over a 2-year period. The patient exhibited chronic erythema, exudation, ulcers, and nail destruction. Imaging studies and pathological biopsies confirmed a diagnosis of moderately differentiated squamous cell carcinoma involving multiple digits. Despite undergoing surgical excision and photodynamic therapy, local recurrence was observed 3 months later, and the patient refused further treatment. He was subsequently lost to follow-up. CONCLUSIONS This case underscores the aggressiveness of multifocal digital sarcomatoid squamous cell carcinoma and the challenges in clinical diagnosis, highlighting the importance of early intervention to improve patient outcomes. This case also emphasizes that sarcomatoid squamous cell carcinoma of the digits is highly aggressive, prone to early recurrence despite initial surgery, and necessitates extensive resection and close follow-up from the outset.