Granular cell tumor of the trachea as a rare cause of dyspnea in a young woman.

Tracheal granular cell tumors are rare neurogenic neoplasms characterized by an indolent behavior. We report the case of a young woman affected by this tumor with non-specific clinical presentation. We performed a literature search in order to identify all the cases of tracheal granular cell tumor and to summarize the current state of knowledge about this rare disease.

Collapse of a new type of self-expanding metallic tracheal stent.

Alveolus TB-STS is a new self-expanding, completely polyurethane-covered, metallic stent which has been designed to be successfully used even in the treatment of non-neoplastic airway strictures as it is supposed to be removable. We recently observed the collapse of an Alveolus tracheal stent, causing dyspnea and hemopthysis, in a 63-yr-old female patient with post-intubation tracheal stenosis. Such a complication, which to our knowledge has never been previously reported with metallic stent use, forced us to remove the stent.

Asthma is not a common cause of severe chronic respiratory failure in non-smokers: ALOT study.

BACKGROUND: Little is known about the long-term natural history of asthma and the long-term clinical and functional consequences in non-smoking patients. From a functional point of view, non-smoking asthmatic patients may have a significantly greater decline in forced expiratory volume in one second (FEV1) compared with non-asthmatic subjects and may develop chronic irreversible (fixed) airflow limitation. This has been related to the physiological consequences of chronic airway inflammation causing airway remodeling. However these lesions are all potentially reversible and there is little radiological evidence indicating lung destruction (pulmonary emphysema), which is potentially irreversible, in non-smoking asthmatics. Severe chronic respiratory failure is the major cause of mortality in patients with severe chronic lung diseases. Domiciliary long-term oxygen therapy (LTOT) is an accepted treatment for patients with severe chronic respiratory failure. Our reasoning, therefore, was that if asthma is a cause of severe chronic respiratory failure in non-smokers we should be able to find non-smoking asthmatics within a large population of patients on LTOT. The aim of our study (Asthma and Long-term Oxygen Therapy, "ALOT") was to investigate the prevalence of non-smoking asthmatics in patients on LTOT in a multi-centre, cross-sectional study. METHODS: Between June and September 2003 we screened all subjects on long-term domiciliary oxygen therapy in three different hospitals in the North-East area of Italy (within the provinces of Ferrara and Bologna). Taken collectively, we have found one-hundred and eighty-four patients on LTOT. We have reviewed their clinical data (age, sex, smoking, history and physical examination, arterial blood gas analysis, pulmonary function). RESULTS: 114 patients (all smokers) fulfilled the diagnostic criteria for COPD. Seventy patients (all smokers) had other diseases. We were unable to find any non-smokers in our screened population of subjects on long-term domiciliary oxygen therapy. Furthermore, there was no past history of asthma and/or acute wheezing episodes in either of the patient groups. CONCLUSIONS: This data suggests that asthma is an uncommon cause of severe chronic respiratory failure necessitating long-term domiciliary oxygen therapy in non-smokers and supports the current consensus that asthma and COPD are different diseases with differing stages of severity and the concept that long-term avoidance of active smoking is fundamental for the prevention of severe chronic respiratory failure.

Spiral CT evaluation of pulmonary emphysema using a low-dose technique.

PURPOSE: To evaluate the diagnostic accuracy and clinical acceptability of low-dose spiral CT for determining pulmonary volumes and emphysema extension in patients with pulmonary emphysema, in comparison with studies based on spiral CT at conventional dose. MATERIALS AND METHODS: We prospectively evaluated eighteen patients, current or former smokers, with a clinical diagnosis of chronic obstructive pulmonary disease. All the patients underwent: HRCT with three scans at predetermined levels; quantitative spiral CT, with two inspiratory scans, one conventional scan at 240 mA, and the second one a low-dose scan at 80 mA. We used the following parameters: 120 kV, rotation time 0.8", scan time less than 20" (single inspiratory breath-hold), layer thickness 7.5 mm, pitch 6 (high speed), interpolation algorithm at 180 degrees. A 3D reconstruction was performed, with segmentation of the lungs and automatic quantification of pulmonary volumes. We compared the volumes of absolute and percent emphysema and the ratings of the dose delivered to the patient (CTDIw and DLP) obtained with the two spiral CT scans with each other and with the respiratory function tests. RESULTS: The average total lung capacity (TLC) obtained by conventional-dose spiral CT (CTs1) was 6889.4 cc (SD +/-1813.2), and the capacity with low-dose spiral CT (CTs2) was 6929.4 cc (SD +/-1811.6). The percentage of emphysema was 39.7% (range: 2.2-63.5%; SD: +/-19.9) for the CTs1 and 41.1% (range: 2.1-66.4%; SD: +/-20). The CTDIw corresponding to CTs1 was 12.2 mGy (range: 11.9-16.4; SD: +/-1), the one corresponding to CTs2, 3.6 mGy (range: 3.6-4.9; SD: +/-0.3). The DLP corresponding to CTs1 was 391.7 mGy x cm (range: 333.3-518.9; SD: +/-46.7), the one corresponding to CTs2 was 117.8 mGy x cm (range: 100.3-156; SD: +/-14). As for the respiratory function tests, the total lung capacity (TLC) obtained by body plethysmography was 7061 cc (SD: +/-2029.7); the percent TLC was 115.9 (range: 66-165; SD: +/-27.6), the forced expiratory volume at one second (FEV1%, percentage of predicted value) was 46.7% (range: 17-123; SD: +/-27.3), residual volume (RV%) as a percentage of predicted value was 186.3 (range: 84-359; SD: +/-80.7), the Tiffeneau index (TI) was 46% (range: 25-71; SD: +/-15.7). We observed a very significant correlation between radiological and functional TLC for both CT methods. The percentage scores for emphysema obtained with the two methods correlated significantly with the functional indexes. The pixel index of CTs1 correlated with TLC% (r=0.87; p<0.0001), FEV1% (r=-0.53; p<0.02), RV% (r=0.76; p=0.004), TI (r=-0.79; p=0.0001). The pixel index of CTs2 correlated with TLC% (r=0.87; p<0.0001), FEV1% (r=-0.56; p=0.01), RV% (r=0.78; p=0.003), TI (r=-0.8; p=0.0001). The adoption of the method with low tube current entailed a highly significant reduction in the estimated dose delivered to patients (CTDIw and DLP) with r=0.9 and p < 0.0001. DISCUSSION AND CONCLUSIONS: Quantitative low-dose spiral CT is a very good method to quantify pulmonary volumes and calculate the extension of the anatomic emphysema. The reduction of mA from 240 to 80 lowers the estimated dose by 30%, without compromising the accuracy of the results. Our study achieved a highly significant correlation between the results obtained with the two spiral CT techniques and between these results and the respiratory function tests. In clinical practice, the easiest way to reduce the dose in spiral CT of the lung is to reduce the tube current. The low-dose method allows a significant reduction in radiation exposure. Further studies are required to establish to what extent the dose can be reduced without increasing in quantum noise and thereby compromising the quality of the study.