Approach to a solid solitary pulmonary nodule in two different settings-"Common is common, rare is rare".

A new solid solitary pulmonary nodule (SPN) is a common feature in the daily practice of physicians, pulmonologists and thoracic surgeons. The etiology and consequently the diagnostic approach is very different in various parts of the world. Identification of malignant nodules is the universal goal to proceed to a potential curable therapy. In countries with a low incidence of inflammatory disease and a high incidence of lung cancer the diagnostic work up includes a positron emission tomography (PET) scan or PET-computer tomography (CT) as a main pillar. In countries with a high incidence of inflammatory and infectious disease and a low incidence in lung cancer this diagnostic work up needs to be adapted. In these settings a PET scan has a limited role and tissue diagnosis, whether with a trans-thoracic, trans-bronchial biopsy or a video-assisted wedge resection is the most targeted approach to determine or exclude malignancy. The evaluation of a solid SPN in the two different situations is outlined in our algorithm. Recommendations stress the value of clinical judgement in different settings, determination of probabilities of malignancy, cost-effective use of diagnostic tools and evaluation of various management alternatives according to the risk profile and the patients preferences.