[Autoantibody positivity with bilateral pulmonary ground-glass opacities and consolidations]

A 52-year-old male patient presented with a 6-month history of cough and exertional dyspnea that had worsened over 2 days. Six months earlier, he had developed exertional dyspnea accompanied by a paroxysmal dry cough. At another hospital, anti-RNP/Sm and anti-Jo-1 antibodies were weakly positive, anti-Ku antibodies were positive, and the rheumatoid factor level was elevated. High-resolution computed tomography (HRCT) of the chest demonstrated pulmonary emphysema, honeycomb pattern in the lower lobes, scattered patchy ground-glass opacities and consolidations, as well as traction bronchiectasis. Bronchoalveolar lavage culture, tuberculosis-related investigations, and liquid-based cytology were all negative for pathogens and malignant cells. He was treated first with glucocorticoids and subsequently with glucocorticoids plus mycophenolate mofetil; however, follow-up chest CT revealed that the pulmonary lesions had increased in extent and density. Upon admission, physical examination revealed crackles bilaterally. Repeat autoantibody testing remained positive. Following multidisciplinary discussion, repeat bronchoscopy was performed, and a transbronchial lung biopsy established the diagnosis of pulmonary adenocarcinoma involving both lungs.