2015 Volume 29 Issue 1 Pages 25-30
We report a 79-year-old man who was diagnosed with multiple metastases of occult primary cancer presenting as thin-walled cavities detected during pneumothorax. The first onset of the left pneumothorax was in July and the second onset was in September 20xx. Computed tomography during the second pneumothorax revealed multiple lung cysts, which were considered to represent pulmonary emphysema. However, the multiple pulmonary cavitary lesions were also suspected to be malignant tumors and several tumor markers were examined. The cytokeratin 19 fragment (CYFRA), which is a tumor marker, was at a high level. While an additional examination was being considered, the patient experienced a third left pneumothorax one month after the second pneumothorax. At that time, the patient was referred to our hospital for close examination and treatment. Pneumothorax was treated by drainage and autologous pleurodesis. F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) showed strong FDG accumulation in the right neck lymph node and low accumulation in a right faucial tonsil, both lungs, and the prostate. Thoracoscopic left lung biopsy and right neck lymph node biopsy were performed, and pathological examination revealed squamous cell carcinoma in both tissues. The cancer was unlikely to be head and neck cancer or prostate cancer according to close inspection. We decided to treat the patient with chemotherapy and radiotherapy of the cervical lymph node as an occult primary squamous cell carcinoma. He is currently alive and being treated for cancer 17 months after the diagnosis.
