[A Case of Pneumothorax Developing During Ramucirumab Combination Chemotherapy for Ascending Colon Cancer with Multiple Pulmonary Metastases].

The patient was a 63-year-old woman.In 2014, she underwent surgery for metastatic ovarian cancer, but intraoperative findings revealed peritoneal dissemination.A colonoscopy after surgery revealed a type 2 tumor in the ascending colon, and a biopsy revealed a diagnosis of tub2.After chemotherapy, an ileocecal resection was performed for ascending colon cancer.She subsequently developed multiple lung, liver, and right rib metastases, and in December 2023, FOLFIRI plus RAM therapy was started.In May 2024, a CT scan showed an increase in the right pleural effusion, and she was diagnosed with malignant pleurisy.She underwent thoracic drainage and pleurodesis.FOLFIRI plus RAM therapy was continued, but in August of the same year, she developed nausea and difficulty breathing, and a CT scan revealed a right pneumothorax.The collapse of the right lung was mild, and the patient was admitted to the hospital on an emergency basis and placed on rest.There was no worsening of the pneumothorax, and she was discharged on the 9th day after admission.The mechanism by which the pneumothorax developed in this case was thought to be that intrathoracic pressure increased with nausea and vomiting caused by chemotherapy and increased opioid dosage, leading to the rupture of the pleural dissemination lesion, causing the pneumothorax.