OBJECTIVETo evaluate the high resolution CT (HRCT) features of cyst-like lung adenocarcinoma, explore the correlation between HRCT image features and histopathological characteristics, and observe the pathological basis of air-containing space.

METHODSHRCT and histopathologic findings of cyst-like lung adenocarcinoma in 86 patients were investigated retrospectively. The image features of both tumor and air-containing space were analyzed. All surgically resected specimens were reviewed. The pathological analysis included histologic subtype, differentiation degree, and the pathological basis of air-containing space formation. The correlation between HRCT image features and histopathologic grades was analyzed.

RESULTSOn HRCT, intratumoral necrosis was detected in 17 cases (19.8%), air-containing space with septa in 40 cases (46.5%), wall nodule in the air-containing space in 16 cases (18.6%), mixed thick and thin walls of air-containing space in 49 cases (57.0%). Air-containing space and its wall were observed in 63 cases on histological specimens, among which destruction of the alveolar wall by tumor cells might be the pathological basis of air-containing space in 42 (66.7%) cases. Differences of tumor attenuation (P = 0.030), intratumoral necrosis (P = 0.003) and proportion of thin-wall in air-containing space (P = 0.014) among different histopathologic grades were significant. The proportion of thin-wall in air-containing space was negatively correlated with histological grade (r = 0.267, P = 0.015). Differences of tumor contour (P = 0.002), tumor attenuation (P = 0.006), intratumoral necrosis (P < 0.001), septa in air-containing space (P = 0.016) and proportion of thin-wall in the air-containing space (P = 0.005) among different differentiation degrees were significant. The proportion of thin-wall in air-containing space was positively correlated with differentiation degree (r = 0.266, P = 0.013).

CONCLUSIONSOn HRCT, cyst-like lung adenocarcinoma may manifest as an air-containing space with septa and mixed thin and thick walls, whereas wall nodule of air-containing space and intratumoral necrosis are not common. There is a certain correlation of HRCT manifestation with pathological subtype grading and tumor differentiation. Analysis of HRCT image features is helpful in prediction of the histopathologic grading and histological differentiation degree of the tumors. Destruction of the alveolar structure by tumor cells may be the main pathological basis of air-containing space formation in cyst-liked lung adenocarcinoma.