What happened, in summary

This 70-year-old woman with active tobacco use and a 40-pack-year history presented with shortness of breath, cough with small-volume hemoptysis, 11 pounds of unintentional weight loss, chills, night sweats, and pleuritic chest pain. Initial imaging raised strong concern for lung cancer. Chest CT showed a 4 cm pleural-based left upper-lobe mass invading the major fissure, a 2.3 cm spiculated left upper-lobe nodule, a 2.1 cm left lower-lobe spiculated nodule, and a small left pleural effusion that could not be sampled. Bronchoscopy and lymph-node sampling were performed. Cytology from the left upper-lobe nodule showed rare p40-positive, TTF-1/Napsin-negative cells described as neoplastic, while one ipsilateral hilar lymph node had rare mildly atypical p40-positive squamous cells in a background of acute inflammation. Other sampled mediastinal lymph nodes were negative for carcinoma. A tumor board initially discussed likely T4N1M0 Stage IIIA non-small-cell lung cancer and planned more tissue and systemic chemotherapy. After she stopped smoking, PET/CT already showed decreased lesion size and resolution of the pleural effusion. A CT-guided core biopsy of the dominant left upper-lobe mass then showed thickened alveolar walls, chronic inflammation, and hemosiderin-laden macrophages, consistent with organizing pneumonia and smoking-related inflammatory change. Her diagnosis was changed before cancer therapy began, and chemotherapy was avoided. Surveillance CT 3 months later showed complete resolution of the previously concerning abnormalities. Her symptoms and lesions improved without systemic cancer therapy. The clinical course shows why repeat tissue confirmation can prevent unnecessary cancer treatment when imaging and limited cytology point in different directions.