Tree-in-bud pattern in central lung cancer: CT findings and pathologic correlation

Radiological precursor lesions of lung squamous cell carcinoma: Early progression patterns and divergent volume doubling time between hilar and peripheral zones

OBJECTIVES

This study investigated the early progression patterns of lung squamous cell carcinoma (SqCC) on computed tomography (CT) images.

MATERIALS AND METHODS

In total, 65 patients with SqCC who underwent surgical resection and two CT scans separated by an interval of at least 6 months were enrolled. We categorized the findings of the initial and at-diagnosis CT images into five patterns as previously reported. The volume doubling time (VDT) was calculated for measurable lesions.

RESULTS

A single nodule pattern on CT images at-diagnosis was most common in 56 (86.2 %) patients, in line with practical clinical findings. However, the patterns were diverse in the initial images, with 28 (43.1 %) patients displaying atypical findings, including multiple nodules (3.1 %), endobronchial lesions (20.0 %), subsolid nodules (10.8 %), and cyst wall thickening (9.2 %). All endobronchial lesions were located in the central/middle zone of the lung field, whereas lesions presented as multiple nodules, subsolid nodules, and cyst wall thickening were predominantly observed in the peripheral zone. The differences in the developed zones were reflected in the median VDT, and the tumors with an initial endobronchial pattern had a significantly shorter VDT than those with a subsolid nodule pattern (median: 140 days vs 276 days, p < 0.001).

CONCLUSIONS

Lung SqCC initiated with various CT image patterns, although most tumors ultimately developed a single nodule pattern by diagnosis. The initial CT image patterns differed between the hilar and peripheral zones, suggesting a difference in the progression scheme, which was also supported by differences in VDT.

Thoracic Imaging in China: Yesterday, Today, and Tomorrow

Thoracic imaging has been revolutionized through advances in technology and research around the world, and so has China. Thoracic imaging in China has progressed from anatomic observation to quantitative and functional evaluation, from using traditional approaches to using artificial intelligence. This article will review the past, present, and future of thoracic imaging in China, in an attempt to establish new accepted strategies moving forward.

Tree-in-Bud Pattern of Pulmonary Tuberculosis on Thin-Section CT: Pathological Implications

The “tree-in-bud-pattern” of images on thin-section lung CT is defined by centrilobular branching structures that resemble a budding tree. We investigated the pathological basis of the tree-in-bud lesion by reviewing the pathological specimens of bronchograms of normal lungs and contract radiographs of the post-mortem lungs manifesting active pulmonary tuberculosis. The tree portion corresponds to the intralobular inflammatory bronchiole, while the bud portion represents filling of inflammatory substances within alveolar ducts, which are larger than the corresponding bronchioles. Inflammatory bronchiole per se represents the “tree” (stem) and inflammatory alveolar ducts constitute the “buds” or clubbing. “Clusters of micronodules”, seen on 7-mm thick post-mortem radiographs with tuberculosis proved to be clusters of tree-in-bud lesions within the three-dimensional space of secondary pulmonary lobule based on radiological/pathological correlation. None of the post-mortem lung specimens showed findings of lung parenchymal lymphatics involvement.

Clinical and radiological characteristics of central pulmonary adenocarcinoma: a comparison with central squamous cell carcinoma and small cell lung cancer and the impact on treatment response

Purpose

The proportion of central pulmonary adenocarcinoma (ADC) in central-type lung cancer has been gradually increasing due to the overall increasing incidence of pulmonary ADC. But the clinical and radiological characteristics of central ADCs remain unclear. In this study, we compared the clinical and radiological characteristics of central ADCs with those of small cell lung cancers (SCLCs) and squamous cell carcinomas (SQCCs) and investigated the impact of these characteristics on patients’ treatment response.

Patients and methods

The medical records of 302 consecutive patients with central lung cancer from July 2014 to September 2016 were retrospectively reviewed. There were 99 patients with ADC, 95 with SQCC and 108 with SCLC. Computed tomography images were interpreted by two radiologists. Treatment response was determined by Response Evaluation Criteria In Solid Tumors 1.1.

Results

Univariate analyses found that younger age, female sex, no history of smoking, higher levels of carcinoembryonic antigen (CEA), contralateral hilum lymphadenopathy, contralateral lung metastasis, pleural nodules and pleural metastasis to the interlobular fissure were significantly correlated with central ADC. Multivariate logistic regression analyses revealed that compared with central SQCC, female sex, younger age, no history of smoking, higher levels of CEA and contralateral hilum lymphadenopathy were the significantly independent indicators of central pulmonary ADC. Furthermore, compared with central SCLC, younger age, higher levels of CEA and cytokeratin 19 fragment (Cyfra21-1), lower levels of neuron-specific enolase, pleural nodules and lack of vascular involvement were significantly associated with central ADC. In 85 central ADC patients who received first-line platinum-based chemotherapy, both univariate and multivariate logistic regression analyses revealed that pulmonary emphysema had a negative correlation with treatment response (odds ratio=8.04, p=0.02).

Conclusion

Our study revealed that central pulmonary ADCs exhibited more aggressive clinical and radiological characteristics. Pulmonary emphysema was an independent and negative indicator for treatment response of central ADC.