Quantification of ground-glass opacity on high-resolution CT of small peripheral adenocarcinoma of the lung: pathologic and prognostic implications.

OBJECTIVE: The purpose of our study was to correlate the high-resolution CT findings of small peripheral adenocarcinoma of the lung with underlying histopathology and to evaluate the prognostic implications of the CT findings. MATERIALS AND METHODS: The high-resolution CT findings of small peripheral adenocarcinoma of the lung in 224 patients were analyzed by two independent observers for location, size, marginal characteristics, and extent of ground-glass opacity and necrosis. The pathologic specimens were reviewed by an experienced lung pathologist. RESULTS: One hundred and thirty-two patients had bronchioloalveolar carcinoma and 92 had adenocarcinoma. The extent of ground-glass opacity was greater in bronchioloalveolar carcinomas (mean +/- SD, 29% +/- 31.6%) than in other adenocarcinomas (8% +/- 13.3%) (p < 0.001). The extent of ground-glass opacity was significantly greater in patients without recurrence (p = 0.020) and those without nodal (p = 0.017) or distant (p = 0.007) metastases than in patients with nodal or distant metastases or in whom the carcinoma had recurred. CONCLUSION: The extent of ground-glass opacity in a nodule is greater in bronchioloalveolar carcinomas than in other adenocarcinomas. Greater extent of ground-glass opacity also correlates with improved prognosis.     

High-resolution CT analysis of small peripheral lung adenocarcinomas revealed on screening helical CT

OBJECTIVE: The purpose of this study was to determine the correlation between high-resolution CT morphologic features of small peripheral lung adenocarcinomas and tumor growth patterns. MATERIALS AND METHODS: We examined high-resolution CT morphologic features of 59 small, surgically resected peripheral lung adenocarcinomas (diameter, 6-20 mm) that were detected on screening for lung cancer using low-dose helical CT. Among these adenocarcinomas, 14 (24%) were visible and 45 (76%) were invisible on conventional chest radiography. The correlation between high-resolution CT morphologic features and tumor growth patterns was analyzed. RESULTS: Sixteen (94%) of 17 type A (Noguchi's classification) adenocarcinomas appeared as nodules of pure ground-glass attenuation (high-resolution CT type I). Ten (71%) of 14 type B tumors appeared as heterogeneous, low-attenuation nodules (type II). Seven (29%) of 24 type C tumors appeared as nodules with ground-glass attenuation in the periphery and a high-density central zone (type III), and 12 (50%) of 24 type C tumors appeared as homogeneous nodules with soft-tissue density (type IV). Among tumors with a replacement growth pattern, the size and CT values of type C tumors were larger than those of type A or type B tumors (p < 0.05), whereas the percentage of ground-glass attenuation and retained air space in type C tumors was smaller than those in type A or type B tumors (p < 0.01). All (100%) four type D tumors appeared to be homogeneous nodules with soft-tissue density (type IV). CONCLUSION: Small peripheral lung adenocarcinomas shown on CT exhibit four high-resolution CT patterns that corresponded to the histopathologic findings of different tumor growth patterns.     

Ground-glass opacity on thin-section CT: value in differentiating subtypes of adenocarcinoma of the lung.

OBJECTIVE: The purpose of this study was to determine whether thin-section CT could be used to differentiate small localized bronchioloalveolar carcinoma from peripheral adenocarcinoma having a bronchioloalveolar (replacement) growth pattern of alveolar lining cells and from adenocarcinoma not having a replacement growth pattern on the basis of the extent of ground-glass opacity revealed by thin-section CT. MATERIALS AND METHODS: One hundred twenty-four small, surgically resected, peripheral adenocarcinomas from 119 patients (67 men and 52 women; mean age, 60 years) were studied. Lesion diameters were 0.4-2.0 cm (median, 1.5 cm). The extent of ground-glass opacity within lesions on preoperative thin-section CT was reviewed retrospectively by three thoracic radiologists. On the basis of replacement growth of alveolar lining cells, small adenocarcinomas were classified histologically as localized bronchioloalveolar carcinomas (n = 42) or as adenocarcinomas with (n = 53) or without (n = 29) a replacement growth pattern of alveolar lining cells. RESULTS: The percentage of lesions that had ground-glass opacity was significantly greater in localized bronchioloalveolar carcinomas (mean, 56.7%+/-33.0%) than in adenocarcinomas with a replacement growth pattern (mean, 26.3%+/-25.3%, p < .001) or in adenocarcinomas without a replacement growth pattern (mean, 8.3%+/-4.7%, p < .001). CONCLUSION: Determination of the ground-glass opacity area in each tumor as revealed on thin-section CT was useful for differentiating small localized bronchioloalveolar carcinomas from small adenocarcinomas not having a replacement growth pattern.     

Volumetric growth rate of stage I lung cancer prior to treatment: serial CT scanning

PURPOSE: To determine the range of growth rates of stage I lung cancers prior to treatment by using volumetric measurement at serial chest computed tomographic (CT) examinations. MATERIALS AND METHODS: The study population comprised 50 patients who underwent two CT examinations at 25-day or greater intervals. Tumor craniocaudal length and cross-sectional diameters and perimeters were used to volumetrically model each tumor in three ways (spherical, elliptical, perimeter). Volumes were compared by determining Pearson correlation coefficients. By using these volumes, tumor doubling time was determined for each patient. RESULTS: Volumes measured with all three methods were highly correlated. With the perimeter method, median doubling time was 181 days, with a very wide range. Eleven (22%) of 50 tumors had doubling times of 465 days or more. There was considerable overlap in doubling time between histologic subtypes. Assuming constant growth, only three (6%) of the 50 tumors would have been the size of a stage IA tumor for less than 1 year. CONCLUSION: Comparison of tumor volumes at serial CT examinations reveals a very wide range of growth rates. Some tumors grow so slowly that biopsy is required to prove they are malignant.     

Papillary adenocarcinoma of the lung: radiologic and pathologic findings

We describe the radiologic and pathologic findings of papillary adenocarcinoma of the lung in three patients. The tumor appeared as a peripheral lung nodule (n = 1) or a mass (n = 2) on chest radiographs. On CT, the tumor appeared as a solitary pulmonary nodule, as a mass containing internal bubble lucencies with surrounding ground-glass opacity and satellite micronodules, and as a triangular mass with satellite micronodules. On pathology, all tumors showed distinct histologic features with papillary architecture, distortion and/or destruction of normal pulmonary architecture, and nuclear atypism.     

High-resolution CT findings of diffuse bronchioloalveolar carcinoma in 38 patients

OBJECTIVE: The purpose of this study was to analyze the high-resolution CT features of diffuse bronchioloalveolar carcinoma and determine the useful findings in differential diagnosis. MATERIALS AND METHODS: High-resolution CT scans of 38 patients with pathologically proven diffuse bronchioloalveolar carcinoma were reviewed. Sequential CT scans were obtained in 15 patients. The high-resolution CT findings were compared with those of eosinophilic pneumonia (n = 22), multiple pulmonary metastases (n = 12), and tuberculosis (bronchogenic: n = 22; miliary: n = 12). RESULTS: High-resolution CT findings of diffuse bronchioloalveolar carcinoma included ground-glass opacity (n = 29), consolidation (n = 29), nodules (n = 28), centrilobular nodules (n = 26), peripheral distribution (n = 19), and air bronchogram (n = 18). According to the major features, high-resolution CT findings of diffuse bronchioloalveolar carcinoma could be classified into three patterns: predominantly ground-glass (n = 4), consolidative (n = 22), and multinodular (n = 12). Most patients with diffuse bronchioloalveolar carcinoma had a mixture of these findings. The frequency of findings of diffuse bronchioloalveolar carcinoma on high-resolution CT was not different from that of tuberculosis, but the predominant distribution of the nodules and areas of ground-glass attenuation differed between the two. Difference in distribution between bronchioloalveolar carcinoma and bronchogenic tuberculosis included ground-glass opacity remote from the consolidation and a lower lung predominance. CONCLUSION: Although these high-resolution CT findings are not specific, the combination of consolidation and nodules and the coexistence of centrilobular nodules and remote areas of ground-glass attenuation are characteristic of diffuse bronchioloalveolar carcinoma.     

肺结节少见CT征象对病变的诊断价值

目的探讨肺结节的少见CT征象,提高周围型肺癌的诊断正确率。方法回顾分析经手术病理或临床治疗证实的186例肺内结节(139例周围型肺癌和47例其它肺内结节)的少见CT征象(多囊状透亮影、肿瘤胸膜侧的模糊小片状影、磨玻璃影)在肺癌和其它结节中的出现率。结果多囊状透亮影和肿瘤胸膜侧模糊小片状影在肺癌中出现率明显高于肺内其它结节(P<0.05)。磨玻璃影在肺癌和其它结节的出现率无显著差异。在肺癌中,磨玻璃影在细支气管肺泡癌中的出现率明显高于其它类型肺癌(P<0.001)。结论多囊状透亮影和肿瘤胸膜侧模糊小片状影对肺癌的诊断有较高价值,肺癌中磨玻璃影的出现常提示细支气管肺泡癌的可能。     

周围型浸润性肺腺癌EGFR基因突变与CT征象及病理的相关性

目的：探讨周围型浸润性肺腺癌表皮生长因子受体(EGFR)基因突变状态与 CT 征象及病理特征的相关性。方法收集193例经病理证实为周围型浸润性肺腺癌的手术标本,采用扩增阻滞突变系统对所有标本行 EGFR基因突变检测,结合胸部 CT征象及病理资料进行回顾性分析。结果193例中EGFR基因突变率为62.2%(120/193)。在CT征象方面：基因突变组与野生型组于横轴位上肿瘤最大直径(Dmax)分别为(2.52±1.01)cm和(3.11±1.34)cm,差异有统计学意义(P<0.05)。受试者工作特征曲线(ROC)提示Dmax=2.01 cm为判断 EGFR基因突变状态的最佳诊断阈值,敏感度与特异度分别为79%和64%。含磨玻璃密度影(GGO)的肿瘤突变率为78.0%,高于无 GGO 者(56.6%),P<0.05。肿瘤不伴有囊腔样改变者突变率为65.5%,高于伴有囊腔样改变者(40.0%),P<0.05。磨玻璃影/肿瘤直径比(G/T)、分叶征、毛刺征、胸膜凹陷征、血管集束征、空气支气管征、空泡征与EGFR基因突变率无显著相关性(P值均>0.05)。在病理特征方面：组织学亚型中以贴壁生长为主型突变率为77.5%,高于其他亚型(58.2%),P<0.05。以实体生长为主型突变率为26.3%,低于其他亚型(66.1%),P<0.05。无淋巴结转移者突变率为66.9%,高于淋巴结转移者(50.9%),P<0.05。结论在周围型浸润性肺腺癌中,部分CT征象及病理特征对于辅助预测 EGFR基因突变状态具有一定价值。     

Localized pure ground-glass opacity on high-resolution CT: histologic characteristics

PURPOSE: The aim of this study is to assess the histologic characteristics in cases of localized pure ground-glass opacity (LPGGO) that do not exhibit consolidation on high-resolution CT (HRCT) images. METHOD: Twenty surgically resected lesions from 20 consecutive cases were retrospectively investigated. Each of the 20 lesions had exhibited LPGGO on HRCT images. The HRCT images and histopathologic findings were examined for correlations. RESULTS: The areas of LPGGO had a maximum diameter of 2.0-24 mm on the HRCT images. Histopathology of the LPGGO lesions resulted in diagnosis of fibrosis (n = 3; 15%), atypical adenomatous hyperplasia (n = 5; 25%), bronchioloalveolar carcinoma (n = 10; 50%), and adenocarcinoma with stromal invasion (n = 2; 10%). Nonaerogenous components corresponding to solid components without normal alveolar septal destruction were pathologically observed in 15 of the 20 lesions. The diameter of the nonaerogenous components varied between 0.2 and 2.0 mm. CONCLUSION: Because 10% of LPGGO lesions include invasive disease, patients with LPGGO should undergo pathologic examination for confirmation.     

Rapidly growing small peripheral lung cancers detected by screening CT: correlation between radiological appearance and pathological features

12 peripheral small lung cancers (< 20 mm) of rapid growth (volume doubling time < 150 days), detected by repeated low dose CT screening, were evaluated to examine their CT features and to correlate such features with histopathological findings. Each patient's CT images, including follow-up and thin section CT images, were studied retrospectively to determine tumour growth rate and CT morphological features. Nine of the tumours exhibited a solid tumour growth pattern: seven of these showed a well defined, homogeneous, soft tissue density with spicular or lobulated margin. These seven tumours included small cell lung cancer (n = 3), moderately differentiated adenocarcinoma (n = 2), poorly differentiated adenocarcinoma (n = 1) and squamous cell carcinoma (n = 1). The other two tumours, a moderately differentiated adenocarcinoma and a well differentiated adenocarcinoma, appeared as irregular, soft tissue density nodules with poorly defined margins. The latter exhibited an air bronchogram pattern and a small cavity. The remaining three tumours exhibited a lepidic tumour growth pattern. They showed ground glass opacity or ground glass opacity with a higher density central zone on CT images and were well differentiated adenocarcinomas. In conclusion, most peripheral small lung cancers of rapid growth were adenocarcinomas. They also included small cell lung cancer and squamous cell carcinoma. The majority showed solid tumour growth pattern and lacked an air bronchogram and/or small air spaces in the nodule. Some well differentiated adenocarcinomas with lepidic tumour growth pattern also showed rapid growth.     

T1 lung cancer on CT: frequency of extrathoracic metastases

PURPOSE: To determine the frequency of extrathoracic metastases in T1 non-small-cell lung cancer. METHOD: Ninety patients with T1 lung cancer identified on CT were included. Extrathoracic metastases were evaluated at the time of initial diagnosis and during a 1-year follow-up study. The frequency of metastases was compared in terms of cell type (squamous or nonsquamous), size (<2 cm or >2 cm), and the initial CT findings of the tumor. RESULTS: Extrathoracic metastases were identified in 12 (13%) of 90 patients at the time of diagnosis and in 10 patients at the 1-year follow-up study (total, 22 of 90 [24%] patients). Tumors with ground-glass opacity on CT were associated with a significantly lower prevalence of metastases (p = 0.042). The area of ground-glass opacity was seen in 1 of 13 (85%) patients with bronchioloalveolar carcinoma and in 12 of 53 (23%) patients with adenocarcinoma other than bronchioloalveolar carcinoma (p < 0.001). There was no significant difference in the prevalence of metastases between squamous and nonsquamous cell carcinoma, between tumors smaller than 2 cm (n = 17) and larger than 2 cm in diameter (n = 73) and between tumors with or without mediastinal nodal metastases (p>0.05). CONCLUSION: Extrathoracic metastases were apparent at the initial examination in 13% of patients and at the 1-year follow-up examination in 11% of patients. The prevalence is significantly lower in tumors with ground-glass opacity.     

Peripheral lung adenocarcinoma: correlation of thin-section CT findings with histologic prognostic factors and survival

PURPOSE: To evaluate the prognostic importance of thin-section computed tomographic (CT) findings of peripheral lung adenocarcinomas. MATERIALS AND METHODS: The subjects were 127 patients with adenocarcinomas smaller than 3 cm in largest diameter who underwent at least a lobectomy with hilar and mediastinal lymphadenectomy. The margin characteristics of nodules and the extent of ground-glass opacity (GGO) within the nodules at preoperative thin-section CT were analyzed retrospectively. Regional lymph node metastasis (LNM) and vessel invasion (VI) were histologically examined in surgical specimens. Survival curves were calculated according to the Kaplan-Meier method. RESULTS: The frequencies of LNM (4% [1 of 24]) and VI (13% [three of 24]) in adenocarcinomas with GGO components of more than 50% were significantly lower than those with GGO components of less than 10% (LNM, P <.05; VI, P <.01). The patients with GGO components of more than 50% showed a significantly better prognosis than those with GGO components less than 50% (P <.05). All 17 adenocarcinomas smaller than 2 cm with GGO components of more than 50% were free of LNM and VI, and all these patients are alive without recurrence. Coarse spiculation and thickening of bronchovascular bundles around the tumors were observed more frequently in tumors with LNM or VI than in those without LNM or VI (P <.01). CONCLUSION: Thin-section CT findings of peripheral lung adenocarcinomas correlate well with histologic prognostic factors.     

18F-FDG PET/CT显像联合HRCT对孤立性原发肺浸润性黏液腺癌的诊断价值

目的探讨孤立性原发肺浸润性黏液腺癌18F-FDG PET/CT显像和HRCT征象及两者联合对该病的诊断价值。方法回顾性分析经病理证实为浸润性黏液腺癌、有18F-FDG PET/CT双时相显像及病灶层面同机HRCT扫描资料的9例患者,对PET/CT早期、延迟显像及滞留指数、HRCT征象进行综合分析。结果HRCT图像上表现为2例呈实性结节、病灶周围无类似卫星灶样影,6例实性结节周围伴小点片及磨玻璃样影,1例为单纯磨玻璃样结节;分叶征(6例)、血管集束征(6例)、支气管充气征(4例)、空泡征(2例)、毛刺征(1例);18F-FDG PET/CT融合图像上8例病灶表现为不均匀FDG代谢增高,早期显像平均SUVmax为3.2±2.5,延迟现象SUVmax增高6例、降低2例,平均SUVmax为3.5±2.4,平均滞留指数为(10.4±29.3)%,9例均未见纵隔、双侧肺门淋巴结及其他部位转移征象,其18F-FDG PET/CT融合图像上18F-FDG摄取与HRCT相匹配,18F-FDG摄取相对集中于结节的实性区域,病灶磨玻璃区18F-FDG摄取不明显;综合手术病理结果等临床资料证实,9例均为T1N0M0期,与PET/CT分期一致。结论对于影像学检查发现肺孤立性占位患者,在单一影像学检查难以明确诊断的情况下,18F-FDG PET/CT双时相显像上病灶不均匀18F-FDG摄取相对集中于其实性区域的代谢方式与HRCT相联合,可辅助孤立性原发性肺浸润性黏液腺癌的诊断。     

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

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. Received: 4 September 1998; Revised: 25 November 1998; Accepted: 17 March 1999     

Follicular bronchiolitis: thin-section CT and histologic findings.

PURPOSE: To evaluate the thin-section computed tomographic (CT) findings of follicular bronchiolitis and compare them with the histologic findings. MATERIALS AND METHODS: Thin-section CT scans obtained in 12 patients (age range, 24-77 years; mean age, 47 years) with follicular bronchiolitis proved at open lung biopsy were reviewed by two observers. Underlying conditions included rheumatoid arthritis (n = 8), mixed collagen vascular disorders (n = 2), autoimmune disorder (n = 1), and acquired immunodeficiency syndrome (n = 1). All patients had thin-section CT scans (1.0-1.5-mm collimation, 11 patients; 3.0-mm collimation, one patient; high-spatial-frequency reconstruction algorithm) obtained at 10-mm intervals through the chest. RESULTS: The main CT findings included bilateral centrilobular (n = 12) and peribronchial (n = 5) nodules. All 12 patients had nodules smaller than 3 mm in diameter; six patients also had nodules 3-12 mm in diameter. Areas of ground-glass opacity were present in nine (75%) patients. Histologically, all patients had lymphoid hyperplasia along the bronchioles; eight had peribronchiolar lymphocytic infiltration. CONCLUSION: The cardinal CT feature of follicular bronchiolitis consists of small centrilobular nodules variably associated with peribronchial nodules and areas of ground-glass opacity.     

Xanthogranulomatous cholecystitis: radiologic findings with histologic correlation that focuses on intramural nodules

OBJECTIVE: We assessed serial changes in high-resolution CT findings and pulmonary function in patients with nonspecific interstitial pneumonia with fibrosis. MATERIALS AND METHODS: Serial high-resolution CT findings in 13 patients with biopsy-proven nonspecific interstitial pneumonia with fibrosis (mean follow-up period, 11 months) and pulmonary function tests (mean follow-up period, 11 months) were retrospectively analyzed. On CT, the presence and extent of ground-glass opacity, irregular linear opacity, honeycombing, and consolidation were assessed. RESULTS: On initial CT, all patients had areas of ground-glass opacity (mean +/- SD, 21.6% +/-14.4) and irregular linear opacity (5.0% +/- 5.2). The areas of ground-glass opacity decreased significantly on follow-up CT (13.5% +/- 10.5, p = .003). The areas of irregular linear opacity decreased slightly (4.2% +/- 5.2, p > .05). Initial forced vital capacity (69.4% +/- 16.0) improved significantly on follow-up examination (83.9% +/- 16.5) (p = .003). The decrease in the extent of ground-glass opacity on CT correlated significantly with changes in forced vital capacity (r = -.702, p = .007) and diffusing capacity for carbon monoxide (r = - .597, p = .031). CONCLUSION: In patients with nonspecific interstitial pneumonia with fibrosis, areas of ground-glass opacity decrease on follow-up high-resolution CT, and the extent of decrease correlates significantly with that of functional improvement.     

Measurement of localized ground-glass attenuation on thin-section computed tomography images: correlation with the progression of bronchioloalveolar carcinoma of the lung

RATIONALE AND OBJECTIVE: This study was to measure localized ground-glass attenuation (GGA) in the peripheral lung on thin-section computed tomography (CT) and to assess any relationship between the attenuation and lesion. MATERIALS AND METHODS: Twenty-eight surgically resected tumors with localized GGA at thin-section CT were studied. The tumors were histologically diagnosed as 8 atypical adenomatous hyperplasia (AAH), 11 bronchioloalveolar carcinoma (BAC), and 9 BAC with fibrosis. We assumed three concentric circles, which were 0.8, 1.0, and 1.2 times the diameter of each tumor and measured the average CT values corresponding to inside each circle. We calculated a difference in CT value between 0.8 and 1.2 times the diameter of the tumor and defined as the contrast index. RESULTS: The contrast index for tumors with AAH, BAC, and BAC with fibrosis were 19.8 +/- 8.3, 42.5 +/- 16.0 (P < 0.05 vs. group with AAH), and 111.4 +/- 32.6 (P < 0.0001 vs. Group with BAC), respectively. The contrast index became greater in the stepwise progression from AAH to BAC and from BAC to BAC with fibrosis. CONCLUSION: The contrast index correlated histologic findings of the tumor growth in BAC. The contrast index may be a useful and objective measurement for determining surgical treatment for localized GGA in preoperative diagnosis.     

Volume and Mass Doubling Time of Lung Adenocarcinoma according to WHO Histologic Classification

ObjectiveThis study aimed to evaluate the tumor doubling time of invasive lung adenocarcinoma according to the International Association of the Study for Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) histologic classification.Materials and MethodsAmong the 2905 patients with surgically resected lung adenocarcinoma, we retrospectively included 172 patients (mean age, 65.6 ± 9.0 years) who had paired thin-section non-contrast chest computed tomography (CT) scans at least 84 days apart with the same CT parameters, along with 10 patients with squamous cell carcinoma (mean age, 70.9 ± 7.4 years) for comparison. Three-dimensional semiautomatic segmentation of nodules was performed to calculate the volume doubling time (VDT), mass doubling time (MDT), and specific growth rate (SGR) of volume and mass. Multivariate linear regression, one-way analysis of variance, and receiver operating characteristic curve analyses were performed.ResultsThe median VDT and MDT of lung cancers were as follows: acinar, 603.2 and 639.5 days; lepidic, 1140.6 and 970.1 days; solid/micropapillary, 232.7 and 221.8 days; papillary, 599.0 and 624.3 days; invasive mucinous, 440.7 and 438.2 days; and squamous cell carcinoma, 149.1 and 146.1 days, respectively. The adjusted SGR of volume and mass of the solid-/micropapillary-predominant subtypes were significantly shorter than those of the acinar-, lepidic-, and papillary-predominant subtypes. The histologic subtype was independently associated with tumor doubling time. A VDT of 465.2 days and an MDT of 437.5 days yielded areas under the curve of 0.791 and 0.795, respectively, for distinguishing solid-/micropapillary-predominant subtypes from other subtypes of lung adenocarcinoma.ConclusionThe tumor doubling time of invasive lung adenocarcinoma differed according to the IASCL/ATS/ERS histologic classification.     

High-resolution CT characteristics of poorly differentiated adenocarcinoma of the peripheral lung: comparison with well differentiated adenocarcinoma

OBJECTIVE: The purpose of this study was to elucidate the characteristic high-resolution CT (HRCT) findings of poorly differentiated adenocarcinoma (PDA) in comparison with those of well differentiated adenocarcinoma (WDA). MATERIALS AND METHODS: We investigated the HRCT features of surgically resected PDAs (n=21) and WDAs (n=31). We analyzed the margin, CT attenuation, and internal architecture of the tumor and findings in the surrounding lung field, comparing them with the corresponding pathologic findings. RESULTS: Smoothness of the greater part (full-1/2 round) of the tumor and solid appearance were more prevalent in PDAs than WDAs (81% vs. 32%, 100% vs. 35%) [p<0.01]. Air-bronchogram was prevalent in WDAs (58%), but was never seen in PDAs [p<0.01]. Ground-glass opacity in PDAs pathologically corresponded to inflammation and edema in the alveolar space. CONCLUSIONS: Smoothness of the tumor margin and solid appearance without air-bronchogram were more commonly found in PDA than in WDA. HRCT may predict the histological differentiation of adenocarcinoma in selected cases in which differentiation is inconclusive by sputum cytology and transbronchial or CT-guided biopsy.     

Five-year lung cancer screening experience: CT appearance, growth rate, location, and histologic features of 61 lung cancers

PURPOSE: To retrospectively evaluate the computed tomography (CT)-determined size, morphology, location, morphologic change, and growth rate of incidence and prevalence lung cancers detected in high-risk individuals who underwent annual chest CT screening for 5 years and to evaluate the histologic features and stages of these cancers. MATERIALS AND METHODS: The study was institutional review board approved and HIPAA compliant. Informed consent was waived. CT scans of 61 cancers (24 in men, 37 in women; age range, 53-79 years; mean, 65 years) were retrospectively reviewed for cancer size, morphology, and location. Forty-eight cancers were assessed for morphologic change and volume doubling time (VDT), which was calculated by using a modified Schwartz equation. Histologic sections were retrospectively reviewed. RESULTS: Mean tumor size was 16.4 mm (range, 5.5-52.5 mm). Most common CT morphologic features were as follows: for bronchioloalveolar carcinoma (BAC) (n = 9), ground-glass attenuation (n = 6, 67%) and smooth (n = 3, 33%), irregular (n = 3, 33%), or spiculated (n = 3, 33%) margin; for non-BAC adenocarcinomas (n = 25), semisolid (n = 11, 44%) or solid (n = 12, 48%) attenuation and irregular margin (n = 14, 56%); for squamous cell carcinoma (n = 14), solid attenuation (n = 12, 86%) and irregular margin (n = 10, 71%); for small cell or mixed small and large cell neuroendocrine carcinoma (n = 7), solid attenuation (n = 6, 86%) and irregular margin (n = 5, 71%); for non-small cell carcinoma not otherwise specified (n = 5), solid attenuation (n = 4, 80%) and irregular margin (n = 3, 60%); and for large cell carcinoma (n = 1), solid attenuation and spiculated shape (n = 1, 100%). Attenuation most often (in 12 of 21 cases) increased. Margins most often (in 16 of 20 cases) became more irregular or spiculated. Mean VDT was 518 days. Thirteen of 48 cancers had a VDT longer than 400 days; 11 of these 13 cancers were in women. CONCLUSION: Overdiagnosis, especially in women, may be a substantial concern in lung cancer screening.