Spontaneous pneumothorax complicating sunitinib therapy

Dear Editor,

A 65-year-old male was diagnosed with a left renal tumor. Whole body CT scanning was negative for metastasis. The patient underwent left nephrectomy and pathological examination was consistent with a renal clear cell carcinoma graded 3 on Furhman scale. He was elected to undergo treatment with sunitinib. Chest CT six months later revealed small nodular formations in the left upper lobe 0.5-1 cm in diameter, enlarged mediastinal lymph nodes and bilateral pleural effusion.

Treatment with sunitinib was continued and two months later, he was admitted with a 5-day history of shortness of breath and pleuritic chest pain. Chest x-ray and CT showed pneumothorax on the left side. Additionally, a cavitation in one of the previously noted lung nodules was revealed and considered as the most probable cause of pneumothorax. A chest tube was placed urgently. Due to persistent air leakage and lung collapse under closed tube, it was decided that the patient was eligible for surgical intervention. He underwent a left mini muscle-sparing thoracotomy. The existence of ruptured bullae on a metastatic lesion was brought to light (Figure 1). Segmentectomy of the left upper lobe was performed. Additional metastasectomies for the other two lesions and a dry gauze abrasion pleurodesis completed the operation. Pathological examination confirmed the presence of metastatic renal carcinoma. One month later, a new chest CT revealed normal findings and sunitinib was restarted.

Figure 1. Intraoperative image of ruptured bullae on a metastatic lesion (red arrow).

The suggested mechanisms for chemotherapy-associated pneumothorax include rapid tumor lysis and necrosis of the large metastatic pulmonary lesions, enlargement of a rapidly necrotizing tumor, chemotherapy-induced impairment of repair processes, and/or persistent local infection¹.