[Solitary pulmonary nodule: diagnosis criteria and management]

The solitary pulmonary nodule (SPN) is a frequent aspect on the chest X-ray and computed tomography (CT). The diagnosis and management of the SPN is not yet standardized. A high percentage of the SPNs is represented by the malignant lesions (primary lung cancer or metastasis of other extra pulmonary tumors). The first aim of the diagnosis is to evaluate the malignant or benign feature of the SPN using noninvasive techniques: this technique will guide the further diagnosis and treatment management. The noninvasive diagnosis tools are: clinical aspects (age, risk-factors - smoking history, exposure to toxic environment, history of previous tumors or tuberculosis), CT aspects (SPN size, growth rate, nodule's borders, calcifications, "bronchial sign", satellite nodules, invasion), positron emission tomography (PET) and PET-CT fusion, contrast PET-CT (high uptake in malignant processes). An initial high probability benign diagnosis will avoid invasive treatment (pulmonary resection); the initial diagnosis of a malignant process will recommend further invasive investigations (percutaneous or bronchoscopic transbronchial biopsies, thoracoscopy, thoracotomy) and an early appropriate treatment for radical cure with high-survival rate (SPN = stage IA for lung cancer).