Morphological characteristics of malignant solitary pulmonary nodules

The solitary pulmonary nodule is a common radiologic abnormality, which is often detected incidentally. It is defined as focal, round or oval areas of increased opacity in the lung which are caused by a variety of disorders, including neoplasm, infection, inflammations, and vascular and congenital abnormalities. Most of the solitary pulmonary nodules are benign, but up to 30%-40% of them are malignant. The main goal of the radiologic evaluation of suspected solitary pulmonary nodules is to differentiate benign from malignant lesions as accurately as possible. The aim of the study was the assessment of the morphological characteristics of the malignant solitary pulmonary nodules. Large nodule size, irregular, spiculated margins, inhomogeneous density of nodule thick walls in cavitary nodules suggest the presence of the malignant lesion. Smooth, well-defined margins, homogeneous density or the presence of diffuse, laminated, central or popcorn-like calcifications suggest the benign nodule. Diffuse, irregular amorphous calcifications suggest the malignant process. Unfortunately there is a kind of overlapping, and some benign nodules may show features typical of malignancy, and some malignant lesions may appear benign. Morphologic characteristics in computed tomography is however helpful in differentiation of benign from malignant nodules.