Hok Sum Chan

Bronchoscopic aspiration and bronchoalveolar lavage in the diagnosis of sputum smear-negative pulmonary tuberculosis

The ability to make a definitive diagnosis in sputum smear-negative pulmonary tuberculosis by bronchoscopic aspiration, bronchoalveolar lavage (BAL), and examination of postbronchoscopy sputum were compared. Thirty-four patients with lesions on chest x-rays suspected of being pulmonary tuberculosis were entered into the study. The diagnosis of pulmonary tuberculosis was subsequently confirmed in 28 patients and the method of arriving at the final diagnosis was analyzed. A positive acid-fast bacilli (AFB) smear result was obtained in 4/28 (14%) of cases by a combination of bronchoscopic techniques and postbronchoscopy sputum examination. Prebronchoscopy sputum culture was positive in 12/28 (43%). Combined with bronchoscopy specimens, a positive AFB culture result was obtained in 26/28 (93%). Sputum examination, bronchoscopic aspiration, and BAL are complementary techniques and together they give a high yield of definitive diagnosis of pulmonary tuberculosis.

Isolated giant tuberculomata of the liver detected by computed tomography

Isolated giant tuberculomata of the liver are rare, and they are frequently misdiagnosed as primary or secondary tumors of the liver. We describe the computed tomography findings in 2 patients with giant tuberculomata of the liver. One patient had a large low-attenuation lesion with rim enhancement after contrast. The other patient had multiple calcific lesions that did not enhance but showed a rim of hypoattenuation after contrast. Biopsy established the diagnosis and both patients recovered with antituberculous chemotherapy.

Solitary fibrous tumor of pleura: expression of cytokeratins.

&NA; A case of solitary fibrous tumor of the pleura (SFT) is presented. The histogenesis of this uncommon tumor is debated with most investigators favouring origin in submesothelial fibroblasts. Part of the evidence supporting this has been the persistent negativity of the tumor cells for cytokeratin — a feature militating against origin in mesothelial‐lining cells. Our case shows unequivocal focal cytokeratin positivity in tumor cells; we feel that although this indicates mesothelial differentiation it does not militate against origin in submesothelial fibroblasts since, in reactive conditions, these are capable of mesothelial differentiation including expression of cytokeratin. Indeed, it reinforces the hypothesis that SFT is of submesothelial origin. Solitary fibrous tumors can be cellular and atypical. The reactivity of the tumor with cytokeratin, albeit rarely, should be considered in differentiating SFT from sarcomatoid mesothelioma.

Special precautions reduce oropharyngeal contamination in bronchoalveolar lavage for bacteriologic studies

Despite the use of quantitative culture, oropharyngeal contamination of bronchoalveolar lavage (BAL) specimens is still a factor that limits the usefulness of this technique in the diagnosis of lower respiratory tract infection. To investigate whether special precautions could reduce contamination, 20 noninfected patients undergoing diagnostic bronchoscopy were randomized into 2 groups of 10 patients: BAL was performed routinely in group R and with special precautions in group P. These precautions consisted of giving topical lidocaine by inhalation rather than by bolus injection, and passing the bronchoscope used for BAL through a previously inserted endotracheal tube. Quantitative culture of BAL specimens showed that 5 patients in group R (50%), but none of the patients in group P (0%), had at least 1 organism recovered in concentrations ≥104 colony-forming units CFU/ml (p=0.016). Fifteen of 39 isolates (38.5%) in group R and none of 18 isolates in group P (0%) were present in concentration ≥104 CFU/ml (p=0.001). We conclude that oropharyngeal contamination of BAL specimens can be minimized by adopting special precautions during the procedure and by using quantitative culture with 104 CFU/ml as the cut-off point. This may increase the specificity of the technique in the diagnosis of lower respiratory tract infection without reducing its sensitivity.

PEEP ventilation—the treatment for life-threatening re-expansion pulmonary oedema?

Unilateral pulmonary oedema following delayed reexpansion of a pneumothorax was first described by Carlson in 1959 (1). Since then over 30 cases have been reported (2-5). Besides treatment with oxygen, a wide variety of modalities including diuretics, plasma expanders, aminophylline, morphine, digitalis and steroid have been employed. Mechanical ventilation was used in three patients. Most patients recovered but a fatal outcome occurred in 15% (2). The mortality rate may be reduced with a better understanding of the pathophysiology of this condition and better treatment strategies for the high-risk cases.