Pleural Liposarcoma: Case Report

Primary liposarcomas of the pleura are extremely rare soft tissue sarcomas, for which radiographic findings have been reported in only a few cases. Although liposarcomas occur most commonly in the lower extremities and retroperitoneum, we encountered a case of pleural liposarcoma arising in the right hemithorax, invading the medial basal segment of the right lower lobe. Thus, herein we report a case of primary pleural liposarcoma, along with a review of the literature.

A Case Report of Malignant Localized Fibrous Tumor of the Pleura with Chest Wall Invasion

A localized fibrous tumor of the pleura (LFTP) is a slow growing, rare primary pleural neoplasm. Typically, it takes the form of a well-delineated large mass lesion based on the pleura. Several radiologic descriptions of benign LFTP have been published, but the radiologic findings of malignant LFTP involving invasion of the chest wall have not been reported. We describe a case of malignant LFTP with chest wall invasion, confirmed pathologically, and review the literature.

Differential CT Features between Malignant Mesothelioma and Pleural Metastasis from Lung Cancer or Extrathoracic Primary Tumor Mimicking Malignant Mesothelioma

PURPOSE: To evaluate the differential CT features found among malignant mesothelioma and pleural metastasis from lung cancer and from extrathoracic primary tumor which on CT mimic malignant mesothelioma. MATERIALS AND METHODS: Forty-four patients who on chest CT cans showed pleural thickening suggesting malignant pleural disease and in whom this condition was pathologically confirmed were included in this study. On the basis of their pathologically proven primary disease [malignant mesothelioma (n=14), pleural metastasis of lung cancer (n=18), extrathoracic primary tumor (n=12)]. they were divided into three groups. Cases of lung which on CT showed a primary lung nodule or endobronchial mass with pleural lesion, or manifested only pleural effusion, were excluded. The following eight CT features were retrospectively analyzed: 1) configuration of pleural lesion (type I, single or multiple separate nodules, type II, localized flat pleural thickening, type III, diffuse flat pleural thickening; type IV, type III with pleural nodules superimposed; type V, mass filling the hemithorax), 2) the presence of pleural effusion, 3) chest wall or rib invasion, 4) the involvement of a major fissure, 5) extrapleural fat proliferation, 6) calcified plaque, 7) metastatic lymph nodes, 8) metastatic lung nodules. RESULTS: In malignant mesothelioma, type IV (8/14) or II (4/14) pleural thickening was relatively frequent. Pleural metastasis of lung cancer favored type IV (8/18) or I (6/18) pleural thickening, while pleural metastasis from extrathoracic primary tumor showed a variable thickening configuration, except type V. Pleural metastasis from lung cancer and extrapleural primary tumor more frequently showed type I configuration than did malignant mesothelioma, and there were significant differences among the three groups. Fissural involvement, on the other hand, was significantly more frequent in malignant mesothelioma than in pleural metastasis from lung cancer or extrapleural primary tumor . Metastatic lymph nodes and metastatic lung nodules were significantly more frequent in pleural metastasis from lung cancer and extrapleural primary tumor than in malignant mesothelioma. CONCLUSION: Malignant mesothelioma showed significantly frequent fissural involvement and the frequency with which pleural metastasis from both lung cancer and extrathoracic primary tumor showed type I pleural lesion, metastatic lymph nodes or metastatic lung nodules, was significantly frequent. Even though no CT features for differentiating between pleural metastasis from lung cancer and from extrathoracic primary tumor were found, the CT features stated above would help differentiate malignant mesothelioma from the other two groups.

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.

CT Findings of Pleural Dissemination in Primary Lung Cancer

PURPOSE: To evaluate the CT findings of pleural dissemination in primary lung cancer and the limitations of CT scanning in detecting pleural dissemination in primary lung cancer. MATERIALS AND METHODS: Primary lung cancer with pleural dissemination was diagnosed in 68 patients and confirmed by pleural biopsy, cytology and surgery, and these cases were the subject of this study. Adenocarcinoma accounted for 49, squamous cell carcinoma for 13 and small cell carcinoma for six. Eight CT features, namely the amount of pleural effusion, the contour, extent andlocation of pleural thickening, the shortest distance between pleura and mass, pleural calcification, pleural tailsign and the extent of extrapleural fat proliferation, were evaluated. RESULTS: Pleural effusion was noted in 51 of 68 patients(75%), though in most cases(70%), the amount of this was small. Among 42 patients(62%) in whom thickened pleura, were noted, pleural thickening was thin and irregular in 22(52%), thick and irregular in 16(38%), and thin and regular in 4(10%). The extent of pleural thickening was multifocal in 22 patients(52%),diffuse in 16(38%), and circumferential and single in two(5%). Pleural thickening was more frequently noted at theposterior than the anterior pleura. Pleural abutting was seen in 53 patients(78%). In ten patients(15%), chest CTscans revealed no perceptible pleural abnormalities. CONCLUSION: If in primary lung cancer, the primary lung masscontacts the pleura, and if pleural thickening, even when slight, shows marginal irregularity, pleuraldissemination should be considered. Although CT scanning is very useful for the detection of pleural disseminationin primary lung cancer, about 15% of patients showed no perceptible pleural abnormalities. Other diagnosticmodalities such as thoracoscopy are mandatory for the correct diagnosis of pleural dissemination in primary lung cancer.

Plueral Lipoma: A Case Report

Lipoma is a common benign neoplasm, but lipoma arising from the pleura is rare; it is composed of mature adipose tissue and occasionally fibrous stroma. The tumor shows characteristic radiographic and CT features of pleural mass, and the lesion is homogeneous and low density, with CT numbers indicating fat. The mass was removed by surgery and confirmed as a lipoma originating from the parietal pleura.

Differential Diagnosis of Tuberculous Pleural Effusion and Malignant Pleural Effusion: CT Accuracy and Findings

PURPOSE: To evaluate the diagnostic accuracy of CT in the differential diagnosis of tuberculous and malignant pleural effusion whether or not lung lesions are present, and to investigate the CT findings used for this differential diagnosis. MATERIALS AND METHODS: This study involved 30 patients with tuberculous pleural effusion (mean age, 44.6 years; M:F=19:11) and 20 with malignant pleural effusion (mean age, 57.2 years; M:F=10:10). All 50 patients underwent enhanced CT chest scans, and the respective conditions were pathologically confirmed. Two radiologists unaware of the pathologic results and distribution of patients reviewed these scans retrospectively and independently. They recorded the presence or absence of helpful lung lesions, CT findings of pleural effusions, their diagnoses, and the degree of confidence of their diagnoses. RESULTS: Among the total of 100 answeres, helpful long lesions were found in 57 cases. Fifty-three of 57 diagnoses (93%) were correct and 26 cases (46%) were diagnosed with a high degree of confidence. Thirty-two of 43 cases (74%) without helpful lung lesions were correct and 11(26%) were diagnosed with a high degree of confidence. All diagnoses made with a high degree of confidence were correct, even in cases without helpful lung lesions. Frequent CT findings in tuberculous pleural effusion included diffuse pleural thickening, enhancement of pleura, deposition of extrapleural fat, and pleural calcification; in malignant pleural effusion, nodular pleural thickening, pleural thickening over 1cm and associated lymphadenopathy were frequent. Mediastinal and circumferential pleural, as well as fissural involvement, were seen in both effusions; there were no statistical differences. CONCLUSION: In most cases, CT provided correct differential diagnosis between tuberculous and malignant pleural effusion. It can help determine the nature of associated lung and pleural lesions, and specific findings of the latter, and can accurately differentiate tuberculous and malignant pleural effusion.

CT Findings of Diffuse Pleural Diseases: Differentiation of Malignant Diseases from Tuberculosis

PURPOSE: To evaluate whether or not previously known CT criteria for differentiating malignant and benign pleural diseases are useful in the differentiation of diffuse malignant pleural diseases and tuberculosis. MATERIALS AND METHODS: We retrospectively analyzed CT scans of 42 patients comprising 20 cases of malignant pleural diseases and 22 cases of tuberculous pleural diseases, according to previously known CT criteria for differentiating malignant and benign pleural diseases. RESULTS: The most common shape of pleural effusion was crescentic in malignant pleural diseases and loculated in tuberculosis. The aggressive nature of pleural effusion, pleural rind, and pleura thickenign was 1.5 times more frequently observed in malignant pleural diseases than in tuberculosis. Smooth thickening or smooth nodular pleural thickening and extrapleural deposition of fat were 1.5 times more frequently found in tuberculous than in malignant pleural diseases. Interruption of pleural thickening was found twice as frequently in malignant pleural diseases as in tuberculosis. Decreased lung volume was found twice as frequently in tuberculous as in malignant pleural diseases. Anatomical mediastinal pleural involvement was three times, and irregular nodular pleural thickening nine times more frequent in malignant pleural diseases than in tuberculosis. The sensitivity and specificity of CT findings above 70%, and thus suggesting malignant pleural diseases, were as follows: 1) aggressive nature of pleural fluid collection extending to the azygoesophageal recess or tongue of the lung (51.5%, 75%); 2) involvement of anatomical mediastinal pleura (69.2%,73.7%); 3) irregular nodular pleural thickening (87.5%, 69%). CONCLUSION: Although there in overlap between previously known CT criteria for the differentiation of benign and malignant pleural diseases, the aggressive nature of pleural fluid collection extending to the azygoesophageal recess or tongue of the lung, the involvement of anatomical mediastinal pleura and irregular nodular pleural thickening may suggest malignant pleural diseases.

Malignant and Benign Diffuse Pleural Disease: Utility of FDG PET in Differential Diagnosis and Comparison with CT

PURPOSE: To assess the utility of 2-[18F] fluoro-2-deoxy-D-glucose (FDG) PET in differentiating malignant and benign diffuse pleural disease, and to compare it with CT. MATERIALS AND METHODS: Both FDG PET and CT scans were performed in 20 consecutive patients with diffuse pleural disease (13 malignant and seven benign cases). In FDG PET, peak standardized uptake value (SUV) as well as visual assessment of abnormally increased uptake in the pleura was evaluated. The results were compared with CT findings. RESULTS: With only visual assessment of PET images, sensitivity, specificity, and accuracy for malignancy were 92%, 43%, and 75%, respectively. With peak SUV of 4.8 or more, the corresponding figures were 100%, 57%, and 85%, respectively, and on CT interpretation, were100%, 57%, and 85%, respectively. Tuberculous empyema simulated malignant pleural disease both on FDG PET (3/6 patients with peak SUV more than 4.8) and CT (3/6 patients). CONCLUSION: For the differentiation of malignant and benign diffuse pleural disease, FDG PET and CT are equally accurate. Combined visual and quantitative assessments of PET images enhance discriminatory ability. Tuberculous empyema simulates malignant pleural disease both on FDG PET and CT.