Development of Thyroid Carcinoma During Treatment With Pembrolizumab in a Lung Cancer Patient

Pembrolizumab, a programmed death 1 inhibitor, has been shown to have clinically significant efficacy in different types of cancer, providing long-term survival benefit for patients with lung cancer. Herein, we report the development of a primary thyroid cancer in a lung cancer patient that was being treated with pembrolizumab. Primary thyroid malignancy (and not only metastatic disease or immunotherapy-induced thyroiditis) should be considered in patients with lung cancer being treated with immune checkpoint inhibitors who develop new incidental thyroid lesions on imaging studies. (C) 2020 by The Society of Thoracic Surgeons