Hi there. Pulmonary nodules are siginifiant according to their size at the time of presentation, less than 4mm have low risk of being cancerous, between 4-8mm have intermediate risk requiring follow up CTscans, more than 8 mm and mixed solid/ground glass nodules need to be suspected for cancer, percutaneous needle aspiration biopsy, PET scan need to be done. Certain processes that produce ground glass opacity include pulmonary edema, alveolar proteinosis, alveolitis including sarcoidosis and idiopathic pulmonary fibrosis. Clinically you have sharp pains, so depending on the occupational exposure the physician needs to rule out interstitial lung disease like asbestosis, lung tumor or cancer if you are a chronic smoker. Hope this helps. All the best to you and take care.