Photodynamic therapy with intratumoral injection of photosensitizers combined with immunotherapy brings hope to patients with refractory cutaneous malignant ulcers.

Cutaneous squamous cell carcinoma (CSCC) is common among the elderly, typically treated with surgery. However, for surgery-ineligible patients or those with non-healing wounds progressing to malignant ulcers, non-surgical local treatments are viable. This case details an 80-year-old with recurrent back CSCC and intractable malignant ulcers post-radiotherapy and chemotherapy. Treatment involved Hematoporphyrin Derivative (HpD) Photodynamic Therapy (PDT) with low-dose cindilimab immunotherapy (intravenous and intralesional). Two cycles achieved lesion remission, altering peripheral immune cell counts. HpD-PDT combined with immunotherapy is promising for treating CSCC, particularly with malignant ulcers.