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.

Ground-Glass Opacity in Lung Metastasis from Adenocarcinoma of the Stomach: A Case Report

Ground-glass opacity is a frequent but nonspecific finding seen on high-resolution CT scans of lung parenchyma. Histologically, this appearance is observed when thickening of the alveolar wall and septal interstitium is minimal or the alveolar lumen is partially filled with fluid, macrophage, neutrophils, or amorphous material. It has been shown that ground-glass opacity may be caused not only by an active inflammatory process but also by fibrotic processes. When a focal area of ground-glass opacity persists or increases in size, the possibility of neoplasm-bronchioloalveolar carcinoma or adenoma, or lymphoma, for example- should be considered. Diffuse nonsegmental ground-glass opacity in both lung fields was incidentally found on follow up abdominal CT in a stomach cancer patient and signet-ring cell-type metastatic lung cancer was confirmed by transbronchial lung biopsy. We report a case of diffuse ground-glass opacity seen in metastatic lung cancer from adenocarcinoma of the stomach.

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.

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.

CT Findings of Pleural Dissemination from Lung Cancer

PURPOSE: The purpose of our study was to identify the CT findings that help detect pleural dissemination from lung cancer and to evaluate the usefulness of selected diagnostic criteria. MATERIALS AND METHODS: After a computerized database search of 606 patients who had undergone thoracotomy for primary lung cancer, 23 patients were identified as h aving surgically documented pleural dissemination. From the same database, 50 patients without pleural dissemination during thoracotomy were randomly selected as controls. Preoperative CT scans and medical records were rev i ewed retrospectively, and findings were compared between the two groups. RESULT: One or more of three types of pleural thickening (plaque-like, nodular, and fissural) were identified on CT as the most discriminating finding (sensitivity, 74 % ; specificity, 60 %; p = 0.007). The following findings were also significantly discriminating (p<0.05): contiguity of primary tumor with the pleural surface as seen on CT; adenocarcinoma in cell type; and a peripheral tumor defined as one in which bronchoscopy revealed no endobronchial lesion. The use of combinations of these findings in addition to pleural thickening rendered diagnostic criteria more specific at the cost of the sensitivity. CONCLUSION: During preoperative CT evaluation of lung cancer, the recognition of subtle pleural thickening helps detect pleural dissemination. The likelihood that subtle pleural thickening represents pleural dissemination is increased when a primary tumor is contiguous with the pleural surface, is an adenocarcinoma, or is peripherally located.

Lymphangitic Carcinomatosis of the Lung: Serial Changes on High-Resolution CT

PURPOSE: To present initial and follow-up HRCT findings of lymphangitic carcinomatosis of the lung. MATERIALS AND METHODS: Both initial and follow-up HRCT scans were obtained in 18 patients with lymphangitic carcinomatosis of the lung. After dividing the patients into two groups (with anticancer chemotherapy (n=12) and without chemotherapy (n=6), changes of pulmonary parenchymal abnormalities (percentile increase or decrease in the extent of each pattern) were assessed and compared on initial and follow-up HRCTs. RESULTS: Findings on initial CT were interlobular septal thickening (n=18) (smooth in 15 and mixed smooth and nodular in three), thickening of bronchovascular bundles (n=17), areas of ground-glass opacity (n=15), polygonal lines (n=15), and nodules (n=10). With chemotherapy, the finding of polygonal lines decreased by 20/3%, while findings of ground-glass opacity, bronchovascular bundle thickening, septal thickening, and nodules remained stable. Without chemotherapy, all CT patterns of abnormalities except nodules increased by 45-88%. In three patients who did not undergo chemotherapy, smooth interlobular septal thickening changed to nodular thickening. CONCLUSION: Lymphangitic carcinomatosis of the lung manifests initially as smooth thickening of the interlobular septae, bronchovascular bundle thickening,areas of ground-glass opacity, and polygonal lines, as seen on HRCT. Without chemotherapy, the extent of CT findings increases and there is a tendency for smooth septal thickening to change to nodular thickening. Chemotherapy induces improvement or cessation of the progression of CT findings.