Lung adenocarcinoma mimicking interstitial lung disease: Stage IIB diagnosis after VATS biopsy

What happened, in summary

This 55-year-old firefighter sought care for a persistent dry cough that had lasted 3 months, occurred daily, was worst at night, and disturbed his sleep. He also had 15 days of hoarseness. He had ischemic heart disease treated with a stent 2 years earlier, hypertension, and heavy smoking history. Initial possibilities included inflammatory or interstitial lung diseases, but he did not improve with corticosteroids or antibiotics, and blood and bronchoalveolar-lavage findings did not support eosinophilic pneumonia. High-resolution CT showed multiple bilateral pulmonary nodules, especially in the upper lobes, including a cavitating left lower-lobe nodule and left upper-lobe lesions. It also showed necrotic right paratracheal lymphadenopathy, suspicious lower cervical nodes, bilateral axillary nodes, mild right pleural effusion, and adrenal abnormalities. Because imaging did not fit a single benign diagnosis, he underwent right video-assisted thoracoscopic surgery with right upper-lobe wedge resection, mediastinal lymph node biopsy, and pleural biopsy. The operation was uncomplicated, and he recovered with chest drainage, physiotherapy, and stable oxygenation before discharge. Pathology from the wedge resection showed invasive moderately differentiated lung adenocarcinoma. The mediastinal lymph node biopsy showed metastatic adenocarcinoma, and the pleural biopsy also showed malignant involvement. Immunohistochemistry was CK7-positive, CK20-positive, TTF-1-positive, and CDX2-negative, supporting lung origin. The case classified the cancer as Stage IIB, T1aN2aM0. At early postoperative follow-up, he had occasional shortness of breath and fatigue but no cough, fever, or hemoptysis, and oncology/pulmonology follow-up was arranged. The procedure’s main value was resolving the diagnostic uncertainty after months of symptoms and incomplete response to empiric treatment, allowing the patient to move from suspected inflammatory lung disease to cancer-directed planning.