Malignant Pure Pulmonary Ground-Glass Opacity Nodules: Prognostic Implications

OBJECTIVE: This study was designed to evaluate follow-up results in terms of patient prognosis for malignant pulmonary nodules depicted as pure ground-glass opacity (GGO) lesion observed at high-resolution CT (HRCT). MATERIALS AND METHODS: Surgical removal for malignant GGO nodules was accomplished in 58 patients (26 men, 32 women; mean age, 57 years; age range, 29-78 years). Patient prognoses were assessed by patient clinical status and the presence of changes in nodule size determined after a follow-up HRCT examination. Differences in patient prognoses were compared for nodule number, size, surgical method, change in size before surgical removal, and histopathological diagnosis by use of Fisher's exact test and Pearson's chi-squared test. RESULTS: Of the 58 patients, 40 patients (69%) were confirmed to have a bronchioloalveolar carcinoma (BAC) and 18 patients (31%) were confirmed to have an adenocarcinoma with a predominant BAC component. Irrespective of nodule size, number, treatment method, change in size before surgical removal and histopathological diagnosis, neither local recurrence nor a metastasis occurred in any of these patients as determined at a follow-up period of 24 months (range; 12-65 months). Of 14 patients with multiple GGO nodules, all of the nodules were resected without recurrence in six patients. In the remaining eight patients, the remaining nodules showed no change in size in seven cases and a decrease in size in one case as determined after a follow-up CT examination. CONCLUSION: Prognoses in patients with pure GGO malignant pulmonary nodules are excellent, and not significantly different in terms of nodule number, size, surgical method, presence of size change before surgical removal and histopathological diagnosis.

Pulmonary Paraganglioma Manifesting as an Endobronchial Mass

Thoracic paragangliomas comprise only 1-2% of all paragangliomas, including the adrenal pheochromocytomas, and these tumors are mostly found in the mediastinal compartments (1). To the best of our knowledge, there is only one case report in the pathology literature of endobronchial involvement by a primary pulmonary paraganglioma (2). We report here on the CT and bronchoscopic findings of a case of pathologically proven endobronchial paraganglioma in a 37-year-old woman. In our case, bronchoscopy and CT demonstrated an endobronchial hypervascular mass, which indicated the presence of carcinoid or hypervascular metastasis based on the known incidence of such tumors.

FDG PET/CT and Mediastinal Nodal Metastasis Detection in Stage T1 Non-Small Cell Lung Cancer: Prognostic Implications

OBJECTIVE: We aimed to compare the prognoses of patients with pathologically true negative (P-TN) N2 and PET/CT false negative (FN) results in stage T1 non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Our institutional review board approved this retrospective study with a waiver of informed consent. The study included 184 patients (124 men and 60 women; mean age, 59 years) with stage T1 NSCLC who underwent an integrated PET/CT and surgery. After estimating the efficacy of PET/CT for detecting N2 disease, we determined and compared disease-free survival (DFS) rates in three groups (P-TN [n = 161], PET/CT FN [n = 12], and PET/CT true positive [TP, n = 11]) using the Kaplan-Meier analysis and log-rank test. RESULTS: Pathologic N2 disease was observed in 23 (12%) patients. PET/CT had an N2 disease detection sensitivity of 48% (11 of 23 patients), a specificity of 95% (153 of 161), and an accuracy of 89% (164 of 184). The 3-year DFS rate in the PET/CT FN group (31%, 95% confidence interval [CI]; 13.6-48.0%) was similar to that of the TP group (16%, 95% CI; 1.7-29.5%) (p = 0.649), but both groups had significantly shorter DFS rates than the P-TN group (77%, 95% CI; 72.0-81.2%) (p < 0.001). CONCLUSION: The PET/CT shows a high specificity, but low sensitivity for detecting N2 disease in stage T1 NSCLC. Patients with PET/CT FN N2 disease have survival rates similar to PET/CT TP N2 disease patients, which are both substantially shorter than the survival rate of P-TN patients.

Small Cell Carcinoma Manifesting as a Bulky Thoracic Mass in a Pregnant Woman: A Case Report

The classic presentation of small cell carcinoma is hilar or mediastinal lymph node metastases while the primary tumor remains an occult tumor. Grossly enlarged hilar and mediastinal lymph nodes can be frequently seen on the chest radiographs and CT scans. We report here on a case of small cell carcinoma that manifested as a unilateral bulky thoracic mass in a pregnant woman.

Simple Pulmonary Eosinophilia Detected at Low-dose CT for Lung Cancer Screening

PURPOSE: The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. MATERIALS AND METHODS: From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. RESULTS: 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration (p < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn (p < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. CONCLUSION: Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules or focal GGA are found on the low-dose CT performed in asymptomatic patients with peripheral blood eosinophilia. Short interval follow-up should be recommended to avoid invasive procedures or unnecessary aggressive treatment due to mistaking these lesions as lung cancer or metastatic malignancy.

Evaluation of Computer Aided Volumetry for Simulated Small Pulmonary Nodules on Computed Tomography

PURPOSE: To determine the accuracy of automated computer aided volumetry for simulated small pulmonary nodules at computed tomography using various types of phantoms MATERIALS AND METHODS: Three sets of synthetic nodules (small, calcified and those adjacent to vessels) were studied. The volume of the nodules in each set was already known, and using multi-slice CT, volumetric data for each nodule was acquired from the three-dimensional reconstructed image. The volume was calculated by applying three different threshold values using Rapidia(R) software (3D-Med, Seoul, Korea). RESULTS: Relative errors in the measured volume of synthetic pulmonary nodules were 17.3, 2.9, and 11.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=0.96, p<0.001). For calcified nodules, relative errors in measured volume were 10.9, 5.3, and 16.5% at -200, -400, and -600 HU, respectively, and there was good correlation between true volume and measured volume at -400 HU (r=1.03, p<0.001). In cases involving synthetic nodules adjacent to vessels, relative errors were 4.6, 16.3, and 31.2 % at -200, -400, and -600 HU, respectively. There was good correlation between true volume and measured volume at -200 HU (r=1.1, p<0.001). CONCLUSION: Using computer-aided volumetry, the measured volumes of synthetic nodules correlated closely with their true volume. Measured volumes were the same at each threshold level, regardless of window setting.

Hodgkin's Lymphoma Mimicking Necrotizing Pneumonia: Case Report

This study describes a case of pulmonary Hodgkin's lymphoma of the nodular sclerosing type presenting as a large cavitary mass with air-fluid levels. We also conduct a review of the previous articles on pulmonary Hodgkin's lymphoma.

Comparison of High-resolution CT Findings between Miliary Metastases and Miliary Tuberculosis

PURPOSE: To compare the findings of high-resolution computed tomography (HRCT) between patients with miliary metastases and miliary tuberculosis. MATERIALS AND METHODS: Between May 1998 and April 2002, 11 patients with miliary metastases and 18 with miliary tuberculosis underwent HRCT, and we reviewed the findings. In miliary metastases, the primary lesions were adenocarcinoma of the lung (n=2), stomach (n=1), or pancreas (n=1), or of unknown origin (n=5), and papillary carcinoma of the thyroid (n=2). Two radiologists blinded to the clinical and pathologic data reached a consensus regarding nodule size and margin, their distribution and coalescence, interstitial involvement, and other ancillary HRCT findings. Data were analyzed using the chi-square test. RESULTS: CT scans showed numerous 1 to 5-mm nodules randomly distributed throughout both lungs of all patients. Nodules larger than 1.5 mm in diameter were more often seen in miliary metastases (81.9%). In six (54.5%) patients with miliary metastases and in three (16.7%) with miliary tuberculosis, nodule size varied (p<0.05). Pleural effusion occurred in three (27.3%) patients with miliary metastases and three (16.7%) with miliary tuberculosis. Interlobular septal thickening (100%) and peribronchovascular thickening (63.6%) were more common in miliary metastases than in miliary tuberculosis (p<0.01). Lymph node enlargement was seen in 11 (100%) patients with miliary metastases and five (27.8%) with miliary tuberculosis (p<0.001). CONCLUSION: At HRCT, lymph node enlargement and both interlobular and peribronchovascular thickening are more commonly observed in miliary metastases than in miliary tuberculosis.

Pulmonary Involvement of Kaposi Sarcoma in an AIDS Patient: Radiologic and Pathologic Findings

Kaposi sarcoma is the most common malignancy in aquired immunodeficiency syndrome (AIDS), and when disseminated may involve any organ system. Pulmonary involvement of Kaposi sarcoma in AIDS patients has not been previously reported in Korea and we report one such case, confirmed pathologically at autopsy.

Measurement of Perfusion of Pulmonary Nodules by Electron Beam Tomography

PURPOSE: To investigate the perfusion of pulmonary nodules and the flow pattern revealed by electron beam tomography (EBT), and to evaluate their usefulness in the differential diagnosis of pulmonary nodules. MATERIALS AND METHODS: A prospective perfusion study involving 28 nodules in 23 men and five women (mean age, 57 years) was performed using EBT with the multislice flow mode. There were four phases. Precontrast density (Hounsfield units, HU) in phase 0; perfusion, peak HU and time to peak in phase 1; and mean HU and percentage decrease of HU to peak HU of phase 1 in phases 2 and 3 were measured and compared according to the diagnosis. RESULTS: Malignancy was diagnased in 19 cases [primary lung cancer (n=14); metastatic nodules (n=5)], while nine nodules were benign. Perfusion was significantly higher in malignant nodules than in benign (p<0.001) and a higher mean delay 1 HU (p<0.05) and a significantly short time to peak (p<0.05) were recorded in malignant nodules. In primary lung cancer cases, perfusion was significantly high compared with benign nodules (p<0.001), and a mean delay 1 HU was observed (p<0.05). There was no significant difference in perfusion between primary lung cancer and metastasis. CONCLUSION: Perfusion and flow pattern data measured by EBT can provide the useful information for differentiation between malignant and benign pulmonary nodules.

Pleuropulmonary Blastoma: A Case Report

Primary pulmonary neoplasms are uncommon in children. One such tumor, pleuropulmonary blastoma (PPB), is very rare, highly aggressive and malignant, and originates from either the lungs or pleura. It contains both mesenchymal and benign epithelial elements that resemble fetal lung, and occurs mainly in children aged less than five. The clinal symptoms often suggest upper respiratory tract infection or pneumothorax, but ultrasonography and chest CT scans depict both a large mass occupying an almost entire hemithorax, and a simple lung cyst. Contrast-enhanced CT demonstrates hetergeneous attenuation and a whorled appearance.

Coexisting Bronchogenic Carcinoma and Pulmonary Tuberculosis in the Same Lobe: Radiologic Findings and Clinical Significance

OBJECTIVE: Bronchogenic carcinoma can mimic or be masked by pulmonary tuberculosis (TB), and the aim of this study was to describe the radiologic findings and clinical significance of bronchogenic carcinoma and pulmonary TB which coexist in the same lobe. MATERIALS AND METHODS: The findings of 51 patients (48 males and three females, aged 48-79 years) in whom pulmonary TB and bronchogenic carcinoma coexisted in the same lobe were analyzed. The morphologic characteristics of a tumor, such as its diameter and margin, the presence of calcification or cavitation, and mediastinal lymphadenopathy, as seen at CT, were retrospectively assessed, and the clinical stage of the lung cancer was also determined. Using the serial chest radiographs available for 21 patients, the possible causes of delay in the diagnosis of lung cancer were analyzed. RESULTS: Lung cancers with coexisting pulmonary TB were located predominantly in the upper lobes (82.4%). The mean diameter of the mass was 5.3 cm, and most tumors (n=42, 82.4%) had a lobulated border. Calcification within the tumor was seen in 20 patients (39.2%), and cavitation in five (9.8%). Forty-two (82.4%) had mediastinal lymphadenopathy, and more than half the tumors (60.8%) were at an advanced stage [IIIB (n=11) or IV (n=20)]. The average delay in diagnosing lung cancer was 11.7 (range, 1-24) months, and the causes of this were failure to observe new nodules masked by coexisting stable TB lesions (n=8), misinterpretation of new lesions as aggravation of TB (n=5), misinterpretation of lung cancer as tuberculoma at initial radiography (n=4), masking of the nodule by an active TB lesion (n=3), and subtleness of the lesion (n=1). CONCLUSION: Most cancers concurrent with TB are large, lobulated masses with mediastinal lymphadenopathy, indicating that the morphologic characteristics of lung cancer with coexisting pulmonary TB are similar to those of lung cancer without TB. The diagnosis of lung cancer is delayed mainly because of masking by a tuberculous lesion, and this suggests that in patients in whom a predominant or growing nodule is present and who show little improvement of symptoms despite antituberculous or other medical therapy, coexisting cancer should be suspected.

Radiofrequency Ablation of Lung Cancer: Preliminary Report

PURPOSE: Radiofrequency ablation (RFA) of lung cancer in animals and humans has been described in previously published reports. The aim of this study was to present our preliminary experience of treatment of lung cancer involving this approach. MATERIALS AND METHODS: Eight patients with lung malignancies [stage IIIB or IV bronchogenic adenocarcinoma (n=6), metastatic squamous cell carcinoma (n=1), metastatic hepatocellular carcinoma (n=1)] underwent RFA treatment. In all cases LeVeen-type electrodes were employed and CT was used to monitor the procedure. One-day and one-month follow-up CT scans were obtained and analyzed. RESULTS: Prior to treatment, tumor diameter ranged from 2.5 to 5 cm; afterwards, low attenuation consistent with coagulative necrosis was observed. Complications included a small amount of pneumothorax (n=4), pleural effusion (n=8), and subcutaneous emphysema (n=1). Tumor size decreased in five patients, was unchanged in two, and increased in one. CONCLUSION: Radiofrequency ablation of lung cancer is safe and may result in a reduced tumor burden.

Diagnostic Usefulness of MRI for Pulmonary Hamartoma: CT, MRI and Histopathologic Correlations

PURPOSE: To determine the diagnostic usefulness of MRI in pulmonary hamartoma, and the significant MRI features other than fat or characteristic calcification, both revealed by CT. MATERIALS AND METHODS: We prospectively studied chest MR images in five patients with pulmonary hamartoma. All underwent narrow-collimated CT scanning and conventional MRI, specimen MRI was available in three cases. Pulmonary nodular size, shape and margin and the presence of intratumoral fat density, calcification and a cleft-like structure were determined. At MRI, the presence and signal intensity (SI) of the cleft-like structure, including intratumoral cystic space and SI of the main portion of the tumor, were analyzed and compared with the findings of specimen MRI, and correlated with the histopathologic findings. In three cases, the typical enhancement pattern revealed by post-contrast MRI was also evaluated. RESULTS: Narrow-collimated CT scanning revealed fat density or popcorn-shape calcification in two cases and a cleft-like structure in one. The other two cases showed neither fat nor calcification. At MRI, however, all five cases showed a cleft-like structure, which was especially evident on T2WI. The detectability of this did not vary between conventional and specimen MRI. The cleft-like structure showed varying SI on T1, and T2WI correlated to variable mesenchymal component including with respiratory epithelial cells lining the cleft. Marginal rim enhancement was noted on all three post-contrast MR images, and correlated with the relatively rich vascularity of the tumor's marginal portion. An enhanced cleft-like structure was noted in two cases. CONCLUSION: The presence of a cleft-like structure, especially prominent on T2WI and with variable SI, is a useful MR finding for the diagnosis of pulmonary hamartoma, and marginal rim enhancement is an ancillary diagnostic MR finding. In particular, MRI is a useful diagnostic tool in cases where a simple pulmonary nodule demonstrates neither fat nor calcification.

Myoepithelioma of the Lung: A Case Report

Myoepithelioma is a rare tumor composed of cells that are morphologically similar to myoepithelial cells. Myoepithelial tumors usually occur in major and minor salivary glands, though have also been found in sweat and mammary glands. Myoepithelioma very rarely originates in lung parenchyma, though can arise from tracheobronchial submucosal glands. We encountered a case of myoepithelioma originating in lung parenchyma, and report the CT findings, including the pathologic characteristics of the disease.

Pulmonary Metastases of Alveolar Soft-Part Sarcoma: CT Findings in Three Patients

Alveolar soft-part sarcoma is a rare soft tissue sarcoma of young adults with unknown histogenesis, and the organ most frequently involved in metastasis is the lung. We report the CT findings of three patients of pulmonary metastases of alveolar soft-part sarcoma, which manifested as clearly enhanced pulmonary nodules or masses. On enhanced scans, some of the masses were seen to contain dilated and tortuous intratumoral vessels.

Concurrent Pneumopericardium and Pneumothorax Complicating Lung Cancer: A Case Report

The coexistence of pneumothorax and pneumopericardium in patients with primary lung cancer is a very rare phenomenon. We report one such case, in which squamous cell carcinoma of the lung was complicated by pneumopericardium and pneumothorax. Several explanations of the mechanisms involved will be discussed.

Concurrent Pneumopericardium and Pneumothorax Complicating Lung Cancer: A Case Report

The coexistence of pneumothorax and pneumopericardium in patients with primary lung cancer is a very rare phenomenon. We report one such case, in which squamous cell carcinoma of the lung was complicated by pneumopericardium and pneumothorax. Several explanations of the mechanisms involved will be discussed.

Atypical Pulmonary Lymphangitic Metastasis Manifesting as Air-space Lesions: A Case Report

Pulmonary lymphangitic carcinomatosis is a common secondary neoplasm of the lung that may result from hematogenous dissemination to small pulmonary arteries and arterioles followed by invasion of the interstitial space and lymphatics, or from the retrograde spread of tumors from mediastinal or hilar lymph nodes. Radiologically, irregular interlobular septal thickening, bronchovascular interstitial thickening and/or lymph node enlargement are observed. In this report, we describe an atypical radiological manifestation of lymphan-gitic metastasis of stomach cancer in a 37-year-old woman admitted for dyspnea on exertion and a cough which had been present for one month. HRCT scanning revealed bilateral multifocal ground glass opacity or consolidation, mild diffuse axial interstitial thickening, and slight pleural effusion. These findings were thought to indicate the existence of an air-space disease rather than metastasis. Open lung and endoscopic biopsy, however, demonstrated the presence of lymphangitic metastasis from stomach cancer.

Bronchus-Associated Lymphoid Tissue (BALT) Lymphoma of the Lung Showing Mosaic Pattern of Inhomogeneous Attenuation on Thin-section CT: A Case Report

The authors present a case of histologically proven bronchus-associated lymphoid tissue (BALT) lymphoma of the lung in a patient with primary Sjogren's syn-drome that manifested on thin-section CT scan as a mosaic pattern of inhomoge-neous attenuation due to mixed small airway and infiltrative abnormalities