A Case of Recurrence after Resection of Gastric and Adrenal Metastases following Resection of Pleomorphic Carcinoma of the Lung in which Pembrolizumab was Effective

Abstract

An 80-year-old man who had been receiving medical treatment as an outpatient after surgery for adenocarcinoma of the left upper lobe of lung was detected to have cystic wall thickening of the right apex of the lung by a chest CT scan 7 months earlier, and a 1.5-cm solid shadow in the same area by another chest CT scan one month earlier. Although definite diagnosis could not be obtained before surgery, laparoscopic partial resection of the right upper lobe was performed with a suspected diagnosis of lung cancer based on imaging findings. Histopathology revealed solid proliferation of highly atypical spindle-shaped cells and giant cells. Pulmonary pleomorphic carcinoma was diagnosed. Four months after the operation, he developed metastases to the right adrenal gland, the stomach, and lymph nodes of the lesser curvature of the stomach. We performed right adrenalectomy and distal gastrectomy with D2 lymph node dissection. The pathological diagnosis was metastases of pulmonary pleomorphic carcinoma. Retroperitoneal recurrence was detected three months after the second operation. Because of high PD-L1 expression was demonstrated in the specimen of the stomach, adrenal gland and lymphnodes, pembrolizumab administration was started and the metastatic lesion disappeared following 24 courses of the regimen. Pembrolizumab administration is sustained as of 28 months after the initial operation and the patient has been free from any recurrences.