Mucoepidermoid carcinoma is an uncommon neoplasm of the tracheobronchial tree, of unknown etiology. Its preferred endobronchial location often results in respiratory symptoms such as obstruction of the airways and lung diseases of slow recovery. They usually are slow growing tumors although they may present an aggressive behavior with local invasion and lymph node metastases depending on their histopathologic characteristics. The mainstay therapy is complete surgical resection either by means of lobectomy or by lung sparing procedures such as bronchotomy and bronchoplasty. Prognosis depends upon the degree of cellular differentiation of the tumors. The authors report a case of this rare neoplasia and describe the clinical and radiographic characteristics, and the surgical treatment.

In cases of recent asthma in which clinical control with the usual treatment (corticosteroids and bronchodilator) is unsatisfactory, it is important to consider other diagnoses, such as congestive heart failure, gastroesophageal reflux or other forms of airway obstruction. We report the case of a female patient with mucoepidermoid carcinoma of the trachea mimicking asthma. The patient presented cough and wheezing, as well as abnormal spirometry results with an obstructive pattern that was responsive to bronchodilators. One year later, the patient presented clinical and spirometric worsening. The chest X-ray revealed no abnormalities. A CT scan showed a vegetative lesion obstructing the tracheal lumen and located 1 cm from the carina. Fiberoptic bronchoscopy showed a finding similar to a bronchial carcinoid tumor. The anatomopathological diagnosis made after surgical resection was low-grade mucoepidermoid carcinoma, without lymph node involvement. Although the flow-volume curve was not suggestive of upper airway obstruction, the spirometry performed after the surgery showed a significant reduction in the degree of obstruction and greater reversibility after bronchodilator use. There was no evidence of recurrence of the disease or of the symptoms after a two-year follow-up period.

Keywords: Bronchial hyperreactivity; Carcinoma, mucoepidermoid; Trachea; Asthma; Lung diseases, obstructive.

Pancoast syndrome consists of signs and symptoms resulting from a tumor affecting the pulmonary apex and adjacent structures. The process is typically caused by a neoplasm. The majority of cases of Pancoast syndrome are caused by bronchogenic carcinoma. The most commonly found histologic subtypes are adenocarcinoma and epidermoid carcinoma. There have been very few reports of small cell lung carcinoma in the genesis of Pancoast syndrome. We describe the case of a patient with Pancoast syndrome caused by small cell lung carcinoma and discuss the aspects related to the diagnosis and treatment.

Keywords: Pancoast syndrome; Small cell lung carcinoma; Lung neoplasms.

Recurrent pneumonia is characterized by frequent infection and infiltrates in one or more lung lobes. The localized form of the disease is caused by intraluminal obstruction, extrinsic compression or structural abnormalities. The pattern, frequency and severity of the infections, together with a thorough review of all chest X-rays, inform the diagnosis. Herein, we report a case of recurrent pneumonia due to endobronchial obstruction by mucoepidermoid carcinoma.

Keywords: Pneumonia; Recurrent; Carcinoma, mucoepidermoid/diagnosis; Tomography, X-ray computed; Case reports

Abstract Objective: To compare four laboratory methods in the diagnosis of pulmonary tuberculosis. Methods: Respiratory secretion specimens were collected from 160 patients suspected of having pulmonary tuberculosis. Direct testing for Mycobacterium tuberculosis was carried out using Ziehl-Neelsen staining, auramine staining, culture on Löwenstein-Jensen (LJ) medium and polymerase chain reaction (PCR). The strains isolated were identified by means of a radiometric method using p-nitro-alpha-acetylamino-beta-hydroxypropiophenone (NAP) and classical methods. The sensitivity of the methods was compared to the gold standard for the diagnosis of pulmonary tuberculosis, based on clinical, radiological and microbiological criteria. Results: Of the 160 patients, 142 were diagnosed with pulmonary tuberculosis according to the gold standard. The sensitivity of Ziehl-Neelsen staining, auramine staining, culture on LJ medium and PCR was 54.2%, 58.4%, 67.6% and 77.5%, respectively, when compared with the diagnostic criterion adopted. All four methods presented 100% specificity. In the identification of mycobacteria, there was high (96.8%) concordance between PCR and the radiometric method using NAP. The sensitivity of PCR was 50.8% in samples with negative sputum smear microscopy results and 98.8% in those with positive results. The sensitivity of PCR was lower in specimens with negative results in sputum smear microscopy and culture than in those with positive results (25.6% and 99.0%, respectively). Conclusions: We found PCR to be a promising method for the diagnosis of pulmonary tuberculosis, even in paucibacillary specimens. Simultaneous identification and faster results are additional advantages of this method.

Keywords: Tuberculosis, pulmonary/diagnosis; Culture media; Polymerase chain reaction; Sputum/microbiology.

This retrospective molecular study involving restriction fragment length polymorphism, using insertion sequence 6110 as a marker, was conducted in order to provide an initial insight into the genetic diversity of Mycobacterium tuberculosis strains isolated in the slums of the Complexo de Manguinhos, located in the city of Rio de Janeiro, Brazil. Of the 67 strains evaluated, 23 (34.3%) were found to belong to clusters (total clusters, 10). Household and social chains of transmission were associated with clustering, in 20% and 60%, respectively. Living in the Conjunto Habitacional Programado 2 slum was associated with clustering. Although not significant, it is relevant that 26% of the clustered strains presented primary resistance. These findings, although possibly underestimating the prevalence due to the failure to analyze all strains, could help improve the local tuberculosis control program.

Keywords: Tuberculosis; Epidemiology, molecular; Mycobacterium tuberculosis/transmission; Polymorphism, Restriction Fragment Length.

Epidemiological studies have demonstrated a causal relationship between smoking and lung cancer. Although most lung cancer cases are linked to smoking, only a minority of heavy smokers develop lung cancer, leading to the notion that genetic factors affect individual susceptibility. The principal molecular changes in lung cancer are seen in tumor suppressor genes, proto-oncogenes, growth factors, telomerase activity, and methylation status of promoters. Well-known agents include angiogenesis-stimulating factors (such as vascular endothelial growth factor), as well as factors related to tumor cell proliferation and apoptosis (epidermal growth factor receptor, p53, K-ras, retinoblastoma and BCL-2). Several of these genetic factors have already been investigated, but no single parameter has yet presented sufficient selectivity regarding prognostic value or therapeutic efficacy. Treatment strategies to cure lung cancer should focus on these early genetic lesions in order to promote their repair or to eliminate these lung cancer cells.

Keywords: Smoking; Lung neoplasms; Genetic markers; Prognosis