2020 Volume 45 Issue 3 Pages 221-227
A 56-year-old man underwent combined surgery for synchronous esophageal carcinoma and lung carcinoma: thoracoscopy-assisted right middle lobectomy for the right lung cancer (invasive adenocarcinoma, pT1aN0, Stage ⅠA1) and thoracoscopic esophagectomy with lymph node dissection for the esophageal cancer (well-differentiated squamous cell carcinoma, pT2N1, pStage Ⅲ). Twelve months after the operation, he presented with a painful subcutaneous elastic-hard tumor on the posterior surface of the left lower leg. Ultrasound examination revealed a hypoechoic tumor, 2.5 × 1.5 cm in diameter, in the left gastrocnemius muscle. Serum carcinoembryonic antigen and squamous cell carcinoma antigen levels were elevated. Based on these findings, we suspected the lesion as a skeletal muscle metastasis from the lung cancer or esophageal cancer, and extirpated the tumor under local anesthesia. We confirmed the smooth surface of the tumor, without invasion of the adjacent muscle fibers during the operation. The histopathological diagnosis of the resected specimen was adenocarcinoma with TTF-1 (-) and PE-10 (±). The patient received combined chemotherapy with CDDP/PEM. However, he presented with local recurrence of the tumor about 1 month after the tumor extirpation. While the tumor proved resistant to combined chemotherapy with CDDP/PEM plus radiotherapy, nivolumab administration (10 courses) proved effective against the skeletal muscle metastasis from the lung adenocarcinoma, inducing tumor regression and improvement of the symptoms. Unfortunately, however, the patient died of respiratory failure associated with acute pulmonary embolism 27 months after the initial surgery. This patient is considered as a very rare case of skeletal muscle metastasis from a lung adenocarcinoma after combined surgery for synchronous esophageal/lung cancers.
