What are GGN and GGO?
= GGN Among various types of the small-cell and non-small-cell lung cancers, adenocarcinoma is the most prevalent type, accounting for more than a third of all primary lung tumors. A type of adenocarcinoma known as small peripheral adenocarcinomas aka ground-glass nodule (GGN) is the common radiographic appearance of such small peripheral lung adenocarcinomas. Radiographic Characteristics of GGNs Radiologically speaking, GGN represents a type of pulmonary nodules (i.e., localized increase of attenuation in the lung parenchyma of a X-ray CT image), which does not completely obscure the underlying normal parenchymal structures such as airways, vessels and interlobular septa (i.e., presenting a focal ground-glass opacity or GGO). GGN is also known as subsolid nodule, while those that completely obscure the lung parenchyma are called solid nodules. GGN covers a spectrum between completely-not-solid and almost-solid opacities, which are clinically categorized into two subtypes: p...