Prolonged Response of Metastatic Programmed Death-Ligand 1 (PD-L1) Negative Basaloid Squamous Cell Carcinoma of the Lung to Maintenance Immunotherapy

Basaloid squamous cell carcinoma (BSCC) is a variant of squamous cell carcinoma that is most often seen as a variety of primary head and neck cancers. BSCC of the lung is rare primary lung cancer and an uncommon histological subtype of non-small cell lung carcinoma. Due to its rarity, there is little published information and research available to direct disease-specific management of BSCC of the lung. Most published cases of basaloid carcinoma of the lung report on surgical management of eligible patients and even less information can be found for metastatic cases. We report a case of a 74-year-old male with stage four (IV) BSCC of the lung who experienced a complete metabolic with partial anatomic response to combined chemotherapy and immunotherapy with carboplatin/nab-paclitaxel/pembrolizumab and has continued to be in partial remission on maintenance immunotherapy with pembrolizumab despite PD-L1-negative status.