Severe Acute Orthopnea: Ipilimumab-Induced Bilateral Phrenic Nerve Neuropathy.

Ipilimumab is a monoclonal antibody used in the treatment of unresectable or metastatic melanoma. Several immune-related adverse events including potential fatal events have been reported following its use. We report a case of a 66-year-old man who presented with severe acute exertional dyspnea and orthopnea following administration of ipilimumab for metastatic melanoma. Although various peripheral neuropathy syndromes associated with ipilimumab have been reported, bilateral phrenic nerve paralysis has not been previously reported. This case also highlights the clinical features of bilateral phrenic nerve neuropathy. Pulmonologists have to be aware of these unusual immune-related respiratory adverse events in patients being treated with monoclonal antibodies.