A 51-Year-Old Man With Dyspnea and a Pulmonary Nodule.

Case presentation: A 51-year-old man presented with chest tightness, exertional dyspnea, and occasional chest pain for 2 years. The patient visited his local hospital initially, and CT scan revealed a ground glass opacity (GGO) located in the right upper lobe (Fig 1A). He was diagnosed as having pulmonary infection and treated with levofloxacin for 12 days. A repeated chest CT scan 14 days later demonstrated a progressed solid nodule with surrounding ground glass opacity (Fig 1B). With a suspicion of carcinoma in situ, right upper lobectomy was performed via video-assisted thoracoscopic surgery at the local hospital. However, the histologic examination did not show any evidence of malignancy, and the symptoms persisted. Fourteen months later, his dyspnea worsened with extremely low exercise tolerance. The patient denied other symptoms (eg, rash, fever, joint pain, aphthous stomatitis, genital ulceration, other symptoms of arteritis). His appetite was decreased but without significant weight loss. He did not smoke and had a history of fully recovered cerebral infarction 9 months ago. There was no family history of respiratory diseases. After 4 months, a CT pulmonary angiography scan revealed filling defects at the left pulmonary artery and left inferior pulmonary artery (Fig 2A). A vascular narrowing was detected at the left superior pulmonary artery. Accompanied with an increased D-dimer level (> 10 mg/L; normal range, 0-0.5 mg/L), a diagnosis of pulmonary embolism was made. The patient was treated with warfarin, and his symptom of dyspnea was partially relieved. He came to our hospital for further treatment 4 months later.