A case of maxillary sinus small cell carcinoma with multiple metastases successfully treated with pembrolizumab

Abstract

Small cell carcinoma of the head and neck is rare and has a poor prognosis due to early distant metastases. There are no established standard therapies for this disease, so it is treated in the same manner as small cell lung carcinoma. We herein report a case of maxillary sinus small-cell carcinoma with multiple metastases that was successfully treated with pembrolizumab. An 85-year-old man presented with proptosis, poor vision, and diplopia. A detailed examination led to a diagnosis of small cell carcinoma spreading from the right maxillary sinus to the orbit, zygoma, and ethmoid sinus, and multiple liver and bone metastases. Due to his advanced age, the patient received palliative radiotherapy for the right maxillary sinus and immunotherapy with pembrolizumab. The maxillary sinus tumors and hepatic metastases showed a complete response after 6 months of immunotherapy. Pembrolizumab may be a new option for the treatment of small cell carcinomas of the head and neck with metastasis.