Abstract
We encountered a rare case of ramucirumab (RAM)-induced chylothorax that resolved after treatment with a thoracic drain in a 75-year-old woman diagnosed with a HER2-positive advanced gastroduodenal carcinoma. Two weeks after initiating RAM and paclitaxel (PTX) treatment, a pleural fluid examination revealed chylothorax. Treatment with a thoracic drain was initially performed; however, continuous drainage was maintained even after the drain was placed. Since no leakage was observed on lymphoscintigraphy, she was treated without surgery or interventional radiology. The drainage volume gradually decreased; the patient was discharged after removing the thoracic drain. PTX alone was readministered, and chylothorax recurrence was not observed. We emphasized the possibility that RAM can cause chylothorax and that lymphoscintigraphy is useful for selecting treatment.