Pneumatocele during sorafenib therapy: first report of an unusual complication

Sorafenib is a multi-kinase inhibitor and a vascular endothelial growth factor (VEGF) inhibitor approved to treat patients with advanced hepatocellular carcinoma, renal cell carcinoma and differentiated thyroid carcinoma. Its most common side effects are asthenia/fatigue, skin toxicity, diarrhea and arterial hypertension. Reported respiratory adverse reactions include dyspnea, cough, pleural effusion and hoarseness. The aim of this report is to describe for the first time the occurrence of pneumatocele in two patients treated with Sorafenib. Patients had no respiratory symptoms and alternative diagnoses were ruled out. Primary tumors were different (liver metastases from a pancreatic neuroendocrine tumor and hepatocellular carcinoma) but both patients had been treated with yttrium 90 radioembolization 9 and 17 months before starting on Sorafenib, respectively. No complications occurred and Sorafenib withdrawal was followed by radiologic improvement.