Nivolumab causing painless thyroiditis in a patient with adenocarcinoma of the lung.

Thyroiditis is characterised by transient hyperthyroidism, followed sometimes by hypothyroidism, and then recovery. We report a case of painless drug-induced thyroiditis-in a patient with no history of any thyroid disorder-treated with Nivolumab (an IgG4 monoclonal antibody against Programmed Death Receptor 1). The purpose of this case report is to increase awareness among clinicians regarding this possible adverse effect from Nivolumab, and discuss the possible pathophysiology and management strategies in such patients.