Pulmonary pleomorphic carcinoma (PPC) is considered to be resistant to chemotherapy and radiotherapy. Here, we report two cases of PPC which were treated with pembrolizumab and platinum-based chemotherapy.
Case 1: A 64-year-old man visited our hospital with a chief complaint of dyspnea on exertion. Chest computed tomography (CT) showed a sizable tumor, 10 cm in diameter, in the right lower lobe. We conducted a CT-guided percutaneous biopsy, which indicated PPC (cT4N2M1a, cStage IV A). Although there was no expression of PD-L1, he was treated with pembrolizumab, carboplatin, and nab-paclitaxel as a first-line chemotherapy, which stabilized the disease.
Case 2: A 77-year-old man presented with dyspnea on exertion. CT showed a tumor less than 7 cm in diameter and atelectasis of the left lung. 18-fluorine fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) imaging showed gluteus medius muscle metastasis. We conducted a bronchoscopy and ultrasound guided biopsy, which revealed PPC (cT3N2M1b, cStage IV A) with a low expression of PD-L1 (tumor proportion score, 10%). He was treated with pembrolizumab, carboplatin, and paclitaxel as a first-line chemotherapy, which led to a partial response.