Lipoma arborescens of the knee: a case report.

Lipoma arborescens is a rare intraarticular lesion of unknown etiology. We describe the radiographic, computerized tomographic, and magnetic resonance (MR) imaging characteristics of lipoma arborescens in a 17-year-old boy presenting with chronic painful swollen knee. Histologic examination after surgical synovectomy confirmed the diagnosis of lipoma arborescens. The fatty nature and frond-like appearance of this lesion can be demonstrated on imaging studies, especially MR imaging. Open synovectomy is curative in most cases. Although lipoma arborescens is rare, it is important to recognize and differentiate it from other synovial lesions by MR imaging.

Correlation of high-resolution CT and pulmonary function in bronchiolitis obliterans: a study based on 24 patients associated with consumption of Sauropus androgynus.

OBJECTIVE: An outbreak of Sauropus androgynus-associated bronchiolitis obliterans occurred in Taiwan in the summer of 1995. We undertook a study of the correlation between high-resolution CT findings and pulmonary function testing in patients from this outbreak. MATERIALS AND METHODS: We evaluated inspiratory-expiratory high-resolution CT scans of 24 patients with S. androgynus-associated bronchiolitis obliterans. The presence of bronchiectasis was assessed by two visual scores (a bronchial dilatation score and a bronchiectasis extent score). Extent of air-trapping was assessed visually and given a score. We also used computer software to assess the extent of air-trapping and generate scores of dynamic attenuation. Spirometry, plethysmography, and diffusion capacity of each patient were also obtained. RESULTS: All four scores had statistically significant correlation with forced expiratory volume in 1 sec (FEV1) (p < .05 for both bronchiectasis scores; p < .001 for both air-trapping scores). The two air-trapping scores had statistically significant correlation with forced vital capacity and diffusion capacity. We found the scores for dynamic attenuation had the greatest correlation with FEV1 (r = .85). We also found that mosaic attenuation was notable on expiratory CT scans alone in nine patients (type 1 air-trapping) and on both inspiratory and expiratory CT scans in 15 patients (type 2 air-trapping). In the latter group, FEV1 was significantly lower (p < .01). CONCLUSION: Findings from high-resolution CT of air-trapping were more important than findings of bronchiectasis when correlating pulmonary function with S. androgynus-associated bronchiolitis obliterans. Type 2 air-trapping suggested a more severe air-flow obstruction than did type 1. Scores for quantitative attenuation generated by computer software were helpful in assessing air-trapping and correlating it with pulmonary function. These findings may apply to patients with bronchiolitis obliterans from other causes.

Primary pleural thymoma.

An unusual thymoma is reported in a 32-year-old woman. The tumor presented as diffuse pleural thickening with encasement of the left lung. Computed tomographic scan and pleural biopsy of this pleural-based lesion were interpreted as favoring a diffuse pleural mesothelioma. After pleuropneumonectomy, pathologic examination revealed a characteristic epithelial thymoma. However, neither mediastinal involvement nor a concurrent mediastinal mass was found at surgery or by radiographic examinations. To our knowledge, only six previous cases of thymomas have been reported as pleural-based tumors for which a mediastinal origin could be excluded (namely, primary pleural thymomas). It is emphasized that in clinical and pathologic diagnosis of a pleural-based lesion thymoma should be considered in the differential diagnosis.