Hi there. A solitary pulmonary nodule on xray chest needs to be evaluated whether it is benign or malignant and needs surgical resection or not. Usually all solitary pulmonary nodules are benign but may represent an early stage of cancer. Solitary nodules causes, are due to neoplastic(benign or malignant), metastasis, lymphoma, hamartoma, connective tissue tumors. it could be a granuloma of tubercular origin, lung abscess etc. CT halo sign or ground glass attenuation surrounding the nodule on CT image indicates TB and biopsy needs to be done bronchoscopically or via Trans thoracic needle aspiration. This should confirm the diagnosis. Hope this helps. Take care.