Pulmonary Metastasis from Prostate Cancer Presenting with Atypical Imaging Features and Respiratory Symptoms: A Case Report

Pulmonary metastases from prostate cancer have diverse imaging findings, most frequently solitary or multiple nodules, and rarely present with prominent respiratory symptoms. Limited or diffuse pulmonary metastases may mimic pneumonia-like radiographic patterns, potentially leading to misdiagnosis and inappropriate treatment. We describe the case of a 66-year-old man with a 7-month history of progressive dyspnea who was initially suspected to have an infectious or inflammatory lung disease. Despite empirical therapy with antibiotics, corticosteroids, and inhaled bronchodilators, the symptoms and radiographic abnormalities worsened. Chest computed tomography (CT) revealed diffuse bilateral airway-centered granular patterns, ground-glass opacities, patchy consolidations, small nodules, and bronchial wall thickening. Laboratory tests revealed elevated serum Krebs von den Lungen-6 (sKL-6) and prostate-specific antigen (PSA) levels, non-elevated serum lung cancer tumor marker levels, and negative sputum cultures. Histopathological examination of the transbronchial lung biopsy specimen revealed adenocarcinoma. 18F-fluorodeoxyglucose positron emission tomography/CT and prostate biopsy confirmed prostate cancer, and thus, pulmonary metastases from prostate cancer were diagnosed. Bilateral orchiectomy resulted in marked clinical improvement, regression of pulmonary lesions, and substantial reductions in serum PSA and sKL-6 levels. Thus, pulmonary metastases from prostate cancer may initially present with respiratory symptoms and atypical imaging features; early recognition can enable timely intervention and favorable outcomes.