Photoimmunotherapy has recently been applied in the treatment of unresectable, locally advanced, or locally recurrent head and neck cancer. One of its associated adverse events is skin damage, and the development of fistulas and ulcers of skin and mucosa after photoimmunotherapy has been reported. Herein, we report a case of oral maxillary cutaneous fistula caused by photoimmunotherapy after recurrence of maxillary cancer following radiotherapy, with concomitant intra-arterial cisplatin administration, tumor resection, and reconstruction. The fistula was successfully closed with free anterolateral thigh flap reconstruction. Although the ulcer and fistula in this case were directly caused by photoimmunotherapy, we also considered the effects of radiotherapy during the previous treatment process when reconstructing the free flap in terms of the debridement technique, reconstruction approach, and wound healing. More than one year has passed since surgery and there has been no fistula or tumor recurrence.
