A review of the literature is devoted to highlighting of the main points relating to the modern actual multidisciplinary problem — single or solitary lung nodules with incidental detection. The main terms that are used in the study of such lesions or the more common term — nodules, as well as their definition are given. Known pathology causes for the development of solitary pulmonary nodules are also presented. The morphological characteristics of such nodules are described by X-ray or tomogram. The main problem if such nodules are detected is to establish their nature and, above all, their malignant or benign nature. Since the further medical tactic of their management are exactly different. Now the main attention is paid to malignant tumors, since they require the fastest most reliable identification and appropriate medical actions.It has been established that accurate determination of nodules etiology by the main indicators of their radiological images is impossible. Although certain dependences of the malignancy risk of nodules on their size, contours and features of optical density have been identified. And only a morphological study allows us to establish the true nature of the nodules. It is believed that over diagnostics of malignancy of pulmonary nodules leads to excessive use of expensive invasive diagnostic procedures, and to some extent harms the patient in cases of benign nodules. The review ends with a list of possible options for medical management when solitary lung nodules of unknown origin are detected. Their disadvantages and advantages are briefly presented.