Nodular foci are not necessarily cancerous, but may also be benign tumors or even inflammatory lesions. A nodular focus is commonly referred to as a mass that presents a solid nodular pattern. Cancerous nodular foci are generally irregular in shape, lobulated, and some even have burrs at the edges, which are not clearly demarcated from the surrounding tissues. Cancerous nodule foci on the body surface are generally hard, fixed and inactive without pressure pain. In contrast, benign nodule foci are regular in shape, with envelope and clearly demarcated from surrounding tissues. Benign nodular foci on the body surface, such as subcutaneous lipomas, are generally soft and have good mobility. Inflammatory nodular foci are usually caused by infections, such as tuberculosis, and appear as dense, round nodular lesions on chest films, CT, and other imaging studies, with clear demarcation from surrounding tissues. Inflammatory nodular foci on the body surface, on the other hand, have significant pressure pain, and the surface skin is seen to be red and swollen with high skin temperature. Therefore, the discovery of nodular foci does not necessarily mean cancer. A preliminary judgment should be made based on the characteristics of the nodular foci, and then supplemented by various examinations to finally determine their nature.