Small peripheral carcinomas of the lung: thin-section CT and pathologic correlation

Abstract

The aim of this study was to clarify the thin-section CT features of small peripheral carcinomas of the lung on the basis of pathologic findings of tumor growth patterns. Thin-section CT and pathologic correlation was evaluated in 19 patients with surgically verified small peripheral carcinomas of the lung ( < 20 mm in size) that had been detected in a screening trial for lung cancer using spiral CT. Four thin-section CT types of nodules were observed: (a) type L1 (4 of 19, 21 %), a fairly well-defined nodule with ground-glass attenuation, corresponding to tumor lepidic growth without alveolar collapse; (b) type L2 (4 of 19, 21 %), a partly lobulated nodule with a low but inhomogeneous attenuation, corresponding to tumor lepidic growth with scattered foci of alveolar collapse; (c) type L3 (4 of 19, 21 %), an ill-defined nodule with an irregularly shaped higher-density central zone in a ground-glass attenuation peripheral zone, accompanied by convergence of the bronchovascular structures from the surrounding lung parenchyma, which corresponded to desmoplastic response in the central zone and to tumor lepidic growth in the peripheral zone; and (d) type H (7 of 19, 37 %), a well-defined nodule with a solid homogeneous attenuation, corresponding to tumor hilic growth. Thin-section CT features of small peripheral carcinomas of the lung can be classified into four types, based on the density distribution of the tumor, which reflect the histologic findings.

Limited value of shape, margin and CT density in the discrimination between benign and malignant screen detected solid pulmonary nodules of the NELSON trial

“…This was consistent with the results of studies performed in usually larger SPN's [11,23,26,27]. Despite these findings, we do not recommend the use of nodule density in the differentiation between malignant and benign nodules because of the large overlap and the wide range of densities observed among the malignant nodules.…”

Role of baseline nodule density and changes in density and nodule features in the discrimination between benign and malignant solid indeterminate pulmonary nodules

“…This might be explained by the inclusion of air, an air bronchogram or regressive changes such as necrosis or hemorrhage within the tumor. These findings are consistent with the results of studies performed in usually larger SPNs [20][21][22][23]. Therefore, nodule density cannot be used in clinical practice to discriminate between malignant and benign nodules because of the wide overlap observed in our series as well as by others in larger solitary pulmonary nodules [20,21,24].…”

Different efficacy of CT screening for lung cancer according to histological type: Analysis of Japanese-smoker cases detected using a low-dose CT screen

“…With regards to the imaging-diagnosis rate for LC, adenocarcinomas, particularly well-to moderately-differentiated adenocarcinomas, are readily detected as cancer by CT, even for lesions with a small diameter, because of their imaging characteristics [19,32]. However, solid lung tumors such as squamous cell carcinoma, and large/small cell carcinoma are often difficult to diagnose when the tumor has a small diameter without gradualgrowth characteristics, as it may be difficult to discriminate these masses from inflammatory lung nodules [33,34].…”