A Case of G‐CSF-producing Invasive Apical Cancer Resected following Preoperative Adjuvant Therapy

The patient was a 47-year-old male with the chief complaints of right shoulder pain and fever. A 10-cm mass was found to be present in the right pulmonary apical region on chest X-ray examination. The mass was diagnosed as a G-CSF-producing invasive apical cancer and the patient underwent chemoradiotherapy followed by right upper lobectomy with combined resection of the chest wall, and lymph node dissection. A very small nodule was noted in the right frontal lobe on brain MRI before surgery, and the final diagnosis was pT3N0M1, stage IV lung adenocarcinoma. For the brain metastasis, gamma knife treatment and chemotherapy were performed after surgery, and there was no recurrence during 16 months after surgery. The prognosis for G-CSF-producing lung cancer and invasive apical cancer is poor. This was a rare and difficult case of lung cancer showing both characteristics of lung cancer.