Primary Salivary Clear Cell Carcinoma with Response to Checkpoint Inhibition: Case Report and Review of the Literature

Abstract

Abstract Introduction Primary salivary clear cell carcinoma (CCC) is a rare tumor of the minor salivary glands that is often seen as low-grade and responsive to resection. Limited data exist for its response to systemic chemotherapy or immune therapy. Case Presentation A 76-year-old male presented with recurrent, widely metastatic salivary CCC over 3 years after local resection with bilateral selective neck dissections. Advanced imaging showed biopsy-confirmed metastasis to the omentum, lungs, pleural effusion, and lymph nodes. Stable disease was achieved with carboplatin/paclitaxel therapy, but treatment was not tolerated by the patient due to side effects. Patient has been treated with single-agent pembrolizumab for 12 cycles with continued disease control and improvement in effusion. Conclusion Despite the low immunogenicity of this tumor, a clinically positive response was achieved with PD-(L)1 inhibition. More research is needed to identify systemic targeted therapies for CCC and tumors with low immunogenicity.