Objective: To establish reproducible electron microscopic criteria for identifying the four major types of neuroendocrine tumors of the lung: carcinoid; atypical carcinoid; large cell neuroendocrine carcinoma; and small cell carcinoma. Methods: Measurements were made on electron micrographs using a digital image analyzer. Sixteen morphometric variables related to tumor cell differentiation were assessed in 27 tumors. The examination under electron microscopy revealed that all of the tumors could be classified as belonging to one of the four categories listed above. Cluster analysis of the morphometry variables was used to group the tumors into three clusters, and Kaplan-Meier survival function curves were employed in order to draw correlations between each cluster and survival. Results: All three clusters of neuroendocrine carcinomas were found to be associated with survival curves, demonstrating the prognostic significance of electron microscopic features. The tumors fell into three well-defined clusters, which represent the spectrum of neuroendocrine differentiation: typical carcinoid (cluster 1); atypical carcinoid and large cell neuroendocrine carcinoma (cluster 2); and small cell carcinoma (cluster 3). Cluster 2 represents an intermediate step in neuroendocrine carcinogenesis, between typical carcinoid tumors and small cell carcinomas. Conclusions: Our findings confirm that electron microscopy is useful in making the diagnosis and prognosis in cases of lung tumor.

Keywords: Neuroendocrine tumors/lung; Microscopy, electron; Cluster analysis; Survival analysis.

The role of immunohistochemistry is to recognize antigens and, consequently, to identify and classify specific cells within a cell population whose morphology is heterogenous or apparently homogenous. The visualization of the antigen-antibody complex is made possible through the addition of either a fluorochrome conjugate or an enzyme to the antibody, which is then viewed under microscopy. Immunohistochemistry can be used in the routine diagnosis of lung cancer, in order to identify biological markers (diagnostic and prognostic). The essential immunohistochemistry panels will be discussed in this review.

Keywords: Immunohistochemistry; Tumor markers, biological; Lung neoplasms.

Objective: Lung cancer patients often experience profound physical and psychosocial changes as a result of disease progression or treatment side effects. Fatigue, pain, dyspnea, depression, and sleep disturbances appear to be the most common symptoms in such patients. The objective of the present study was to examine the prevalence of symptoms in lung cancer patients in order to identify subgroups (clusters) of patients, grouped according to the magnitude of the symptoms, as well as to compare the quality of life among the identified subgroups. Methods: A cross-sectional study involving agglomerative hierarchical clustering. A total of 50 lung cancer patients were evaluated in terms of their demographic characteristics and their scores on three quality of life questionnaires, namely the 30-item European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30), the Functional Assessment of Cancer Therapy-Lung, and the Medical Outcomes Study 36-item Short-form Survey. The cluster analysis took into account the magnitude of the most prevalent symptoms as assessed by the EORTC QLQ-C30 symptom scale scores; those symptoms were fatigue, pain, dyspnea, and insomnia. Results: Three clusters (subgroups)_of patients were identified on the basis of the magnitude of the four most prevalent symptoms. The three subgroups of patients were as follows: patients with mild symptoms (n = 30; 60%); patients with moderate symptoms (n = 14; 28%); and patients with severe symptoms (n = 6; 12%). The subgroup of patients with severe symptoms had the worst quality of life, as assessed by the total scores and by the integrated domains of all three instruments. Conclusions: This study highlights the importance of symptom cluster assessment as an important tool to assess the quality of life of patients with chronic diseases, such as lung cancer.

Background: Knowledge of the rates of drug resistance is one of the pillars of tuberculosis control program evaluation. Data from low-resource countries are scarce and results are delayed due to the techniques employed. There is therefore an urgent need for evaluation of faster and less onerous testing methods. Objective: To compare the performance of rapid colorimetric assays for phenotyping that employ oxidationreduction indicators to determine the susceptibility profile of Mycobacterium tuberculosis with the gold-standard proportion method on Lowenstein-Jensen Medium. Method: We analyzed 166 M. tuberculosis strains of known susceptibility. Minimal inhibition concentrations for isoniazid and rifampicin were determined in microplates, using a liquid medium and Alamar Blue and tetrazolium bromide indicators. To measure agreement the Kappa value was used. Cutoff values between sensitive and resistant strains were defined as 0.2µg/mL and 1.0µg/mL for isoniazid and rifampicin, respectively. Results: There was 100% concordance between Alamar Blue and tetrazolium bromide methods in the determination of minimal inhibition concentrations. Agreement between the colorimetric method and the Lowenstein-Jensen was 95% for isoniazid and rifampicin. Using the colorimetric method, results were obtained within 7 days, in contrast to the 28 days required for the conventional method. Conclusions: Assays to determine minimal inhibition concentrations in liquid medium and employing oxidationreduction indicators proved to be rapid and inexpensive. This method has the potential to become a faster, alternative method for determining susceptibility of M. tuberculosis strains in developing countries.

Keywords: Mycobacterium tubercolis. Disease susceptibility. Isoniazid/therapeutic use. Rifampin/therapeutic use.

Objective: Studies characterizing asthma phenotypes have predominantly included adults or have involved children and adolescents in developed countries. Therefore, their applicability in other populations, such as those of developing countries, remains indeterminate. Our objective was to determine how low-income children and adolescents with asthma in Brazil are distributed across a cluster analysis. Methods: We included 306 children and adolescents (6-18 years of age) with a clinical diagnosis of asthma and under medical treatment for at least one year of follow-up. At enrollment, all the patients were clinically stable. For the cluster analysis, we selected 20 variables commonly measured in clinical practice and considered important in defining asthma phenotypes. Variables with high multicollinearity were excluded. A cluster analysis was applied using a two-step agglomerative test and log-likelihood distance measure. Results: Three clusters were defined for our population. Cluster 1 (n = 94) included subjects with normal pulmonary function, mild eosinophil inflammation, few exacerbations, later age at asthma onset, and mild atopy. Cluster 2 (n = 87) included those with normal pulmonary function, a moderate number of exacerbations, early age at asthma onset, more severe eosinophil inflammation, and moderate atopy. Cluster 3 (n = 108) included those with poor pulmonary function, frequent exacerbations, severe eosinophil inflammation, and severe atopy. Conclusions: Asthma was characterized by the presence of atopy, number of exacerbations, and lung function in low-income children and adolescents in Brazil. The many similarities with previous cluster analyses of phenotypes indicate that this approach shows good generalizability.

Keywords: Asthma/classification; Asthma/etiology; Child; Adolescent.

Objective: To analyze the locations of lung carcinomas in relation to patient gender and smoking status. Methods: In order to test the hypothesis that lung carcinoma location (upper or lower lobe; left or right side) is correlated with smoking status and gender, we conducted a retrospective study of 697 patients with bronchogenic carcinoma treated at the Pulmonology-Oncology Outpatient Clinic of the Federal University of São Paulo. Results: We found that the bronchogenic carcinomas occurring in smokers were more frequently located in the upper lobes, whereas those occurring in nonsmokers were more frequently located in the lower lobes. In women, the neoplasms were more often seen in the lower lobes, especially in nonsmokers. Based on the available data, there were no differences in terms of the side affected (left or right). Conclusion: Overall, bronchogenic carcinomas are predominantly found in the upper lobes. However, in nonsmokers, they occur more frequently in the lower lobes. In females, bronchogenic carcinomas present a tendency to occur more often in the lower lobes.

Keywords: Lung neoplasms; Sex factors; Smoking

Objective: To relate the experience of the staff at a health care facility specializing in the management of patients with aspiration lung abscess. Methods: Diagnostic aspects and therapeutic results of 252 consecutive cases of lung abscess seen in patients hospitalized between 1968 and 2004. Results: Of the 252 patients, 209 were male, and 43 were female. The mean age was 41.4 years, and 70.2% were alcoholic. Cough, expectoration, fever and overall poor health were seen over 97% of patients. Chest pain was reported by 64%, 30.2% presented digital clubbing, 82.5% had dental disease, 78.6% reported having lost consciousness at least once, and 67.5% presented foul smelling sputum. In 85.3% of the patients, the lung lesions were located either in the posterior segments of the upper lobe or in the superior segments of the lower lobe, and 96.8% were unilateral. Concomitant pleural empyema was seen in 24 (9.5%) of the patients. Mixed flora was identified in the bronchopulmonary or pleural secretions of 182 patients (72.2%). All patients were initially treated with antibiotics (mainly penicillin or clindamycin), and postural drainage was performed in 98.4% of cases. Surgical procedures were performed in 52 (20.6%) of the patients (drainage of empyema in 24, pulmonary resection in 22 and drainage of the abscess in 6). Cure was obtained in 242 patients (96.0%), and 10 (4.0%) died. Conclusion: Lung abscess occurred predominantly in male adults presenting dental disease and having a history of loss of consciousness (especially as a result of alcohol abuse). Most of the patients were treated clinically with antibiotics and postural drainage, although some surgical procedure was required in one-fifth of the study sample.

Keywords: Lung abscess; Pneumonia, aspiration; Bacteria, anaerobic; Bacterial infections; Drainage, postural

Background: Dyspnea is a symptom that is difficult to evaluate, especially in occupational diseases. Objective: To evaluate the relationship between chronic dyspnea, in its varying degrees of severity, and the functional repercussions for dysfunction or incapacitation in former workers with asbestosis. Method: A total of 40 former workers diagnosed with asbestosis were evaluated. Dyspnea scores were determined using the modified Medical Research Council scale, the 1984 and 1993 American Medical Association scales, and the Baseline Dyspnea Index. Spirometry, measurement of diffusion capacity for carbon monoxide and cardiopulmonary exercise tests (incremental and submaximal) were also performed. Results: Based on scores obtained using the Medical Research Council and 1984 American Medical Association scales, respectively, 72.5% and 67.5% of the subjects were classified as dyspneic, compared with 37.5% and 31.6%, respectively, using the 1993 American Medical Association and Baseline Dyspnea Index scales. There was greater concordance between the Medical Research Council and 1993 American Medical Association scales, as well as between the 1984 and 1993 American Medical Association scales, when the categories of "absent" and "mild" were grouped. No significant relation was found between dyspnea, as determined by each of the scales, and functional abnormalities - either at rest or during exercise. Conclusion: In individuals with asbestosis, the degree of concordance among the available dyspnea scales varies significantly. There is a real need for dyspnea indices that evaluate respiratory dysfunction at rest and during exercise.

Keywords: Asbestosis/diagnosis. Dyspnea/physiopathology. Spirometry/methods.

Objective: To analyze the impact that comorbidities have on the postoperative outcomes in patients submitted to lobectomy for the treatment of bronchial carcinoma. Methods: A retrospective study of 493 patients submitted to lobectomy for the treatment of bronchial carcinoma was conducted, and 305 of those patients met the criteria for inclusion in the final study sample. The surgical technique used was similar in all cases. The Torrington-Henderson scale and the Charlson scale were used to analyze comorbidities and to categorize patients into groups based on degree of risk for postoperative complications or death. Results: The postoperative (30-day) mortality rate was 2.9%, and the postoperative complications index was 44%. Prolonged air leakage was the most common complication (in 20.6%). The univariate analysis revealed that gender, age, smoking, neoadjuvant therapy and diabetes all had a significant impact on the incidence of complications. The factors found to be predictive of complications were body mass index (23.8 ± 4.4), forced expiratory volume in one second (74.1 ± 24%) and the ratio between forced expiratory volume in one second and forced vital capacity (0.65 ± 0.1). The scales employed proved efficacious in the identification of the risk groups, as well as in drawing correlations with morbidity and mortality (p = 0.001 and p < 0.001). In the multivariate analysis, body mass index and the Charlson index were found to be the principal determinants of complications. In addition, prolonged air leakage was found to be the principal factor involved in mortality (p = 0.01). Conclusion: Reductions in forced expiratory volume in one second, in the ratio between forced expiratory volume in one second and forced vital capacity, and in body mass index, as well as a Charlson score of 3 or 4 and a Torrington-Henderson score of 3, were associated with a greater number of postoperative complications in patients submitted to lobectomy for the treatment of bronchial carcinoma. Air leakage was found to be strongly associated with mortality.

Keywords: Lung neoplasms/surgery; Postoperative complications; Pneumonectomy; Morbidity

Objective: To investigate the reported cases of tuberculosis and of tuberculosis-HIV co-infection in Brazil between 2002 and 2012. Methods: This was an observational study based on secondary time series data collected from the Brazilian Case Registry Database for the 2002-2012 period. The incidence of tuberculosis was stratified by gender, age group, geographical region, and outcome, as was that of tuberculosis-HIV co-infection. Results: Nationally, the incidence of tuberculosis declined by 18%, whereas that of tuberculosis-HIV co-infection increased by 3.8%. There was an overall decrease in the incidence of tuberculosis, despite a significant increase in that of tuberculosis-HIV co-infection in women. The incidence of tuberculosis decreased only in the 0- to 9-year age bracket, remaining stable or increasing in the other age groups. The incidence of tuberculosis-HIV co-infection increased by 209% in the ≥ 60-year age bracket. The incidence of tuberculosis decreased in all geographical regions except the south, whereas that of tuberculosis-HIV co-infection increased by over 150% in the north and northeast. Regarding the outcomes, patients with tuberculosis-HIV co-infection, in comparison with patients infected with tuberculosis only, had a 48% lower chance of cure, a 50% greater risk of treatment nonadherence, and a 94% greater risk of death from tuberculosis. Conclusions: Our study shows that tuberculosis continues to be a relevant public health issue in Brazil, because the goals for the control and cure of the disease have yet to be achieved. In addition, the sharp increase in the incidence of tuberculosis-HIV co-infection in women, in the elderly, and in the northern/northeastern region reveals that the population of HIV-infected individuals is rapidly becoming more female, older, and more impoverished.

Keywords: Tuberculosis/epidemiology; HIV infections/epidemiology; Comorbidity.

Objective: Neuroendocrine cell hyperplasia of infancy (NEHI) is a form of childhood interstitial lung disease characterized by tachypnea, retractions, crackles, and hypoxia. The aim of this study was to report and discuss the clinical, imaging, and histopathological findings in a series of NEHI cases at a tertiary pediatric hospital, with an emphasis on diagnostic criteria and clinical outcomes. Methods: Between 2003 and 2011, 12 full-term infants were diagnosed with NEHI, based on clinical and tomographic findings. Those infants were followed for 1-91 months. Four infants were biopsied, and the histopathological specimens were stained with bombesin antibody. Results: In this case series, symptoms appeared at birth in 6 infants and by 3 months of age in the remaining 6. In all of the cases, NEHI was associated with acute respiratory infection. The most common initial chest HRCT findings were ground-glass opacities that were in the middle lobe/lingula in 12 patients and in other medullary areas in 10. Air trapping was the second most common finding, being observed in 7 patients. Follow-up HRCT scans (performed in 10 patients) revealed normal results in 1 patient and improvement in 9. The biopsy findings were nonspecific, and the staining was positive for bombesin in all samples. Confirmation of NEHI was primarily based on clinical and tomographic findings. Symptoms improved during the follow-up period (mean, 41 months). A clinical cure was achieved in 4 patients. Conclusions: In this sample of patients, the diagnosis of NEHI was made on the basis of the clinical and tomographic findings, independent of the lung biopsy results. Most of the patients showed clinical improvement and persistent tomographic changes during the follow-up period, regardless of the initial severity of the disease or type of treatment.

Keywords: Lung diseases, interstitial/diagnosis; Lung diseases, interstitial/treatment; Tomography, X-ray computed.

Objective: To determine the characteristics of individuals with asthma who are responsive to aerobic training. Methods: This post hoc analysis of pooled data from previous randomized controlled trials involved 101 individuals with moderate to severe asthma who underwent aerobic training. Participants underwent a maximal cardiopulmonary exercise test and completed the Asthma Control Questionnaire and the Asthma Quality of Life Questionnaire before and after a 24-session aerobic training program. Better and worse responders to aerobic training were identified by cluster analysis. Results: Two clusters were identified according to the improvement in peak VO2 after aerobic training (better and worse responders). Characteristics of the better responder group were being older, being female, having higher BMI, and having higher cardiac reserve at baseline when compared with the worse responder group. Also, better responders had worse clinical control, worse quality of life, and lower physical capacity at baseline. After training, worse responders, in comparison with better responders, showed half the improvement in ?peak VO2 (7.4% vs. 13.6%; 95% CI, -12.1 to -0.92%; p < 0.05) and worse asthma control. A weak, negative, but significant association (r = -0.35; p < 0.05) was observed between clinical control and aerobic fitness only in the better responder group. Both groups showed significant improvement in quality of life. Conclusions: Obese individuals with worse exercise capacity, clinical control, and quality of life showed improvement with aerobic training. Moreover, worse responders also improved with training, but to a lesser extent.

Keywords: Asthma; Exercise therapy; Cluster analysis; Status Asthmaticus; Quality of Life; Rehabilitation.

Objective: To propose a methodology for characterizing proficiency in sputum smear microscopy for acid-fast bacilli (AFB) in the diagnosis of tuberculosis and to determine the number of microscopies necessary to establish this proficiency, as well as the quality of the transcription of results, the causes of the discrepancies in the readings (rater or microscope used), and the criterion for classification of microscopy results that poses the most difficulty in characterizing proficiency. Methods: Four hundred sputum smear microscopies for the diagnosis of tuberculosis were analyzed through double-blind readings by six professionals who usually read/supervise microscopies performed in public health care facilities. The sample was stratified to obtain, at least, a reliability of 90% in the double-blind readings, an α error of 5%, and a precision of 3%. The results were analyzed using observed reliability and the kappa index. Results: Thirteen errors (0.27%) were found in the transcription of results. Reliability increased when the three distinct categories of positive results (AFB+, AFB++, and AFB+++) were grouped or when inconclusive results were excluded from the analysis. The quantification of the bacterial load was the classification criterion that posed the most difficulty in establishing proficiency. Using higher quality microscopes increased reliability. Reliability values stabilized only from the reading of 75 microscopies onward. Conclusions: Double-blind sputum smear microscopy readings using a panel containing 75 slides (36 negative, 4 inconclusive, and 35 positive) proved to be appropriate for characterizing proficiency in sputum smear microscopy for the diagnosis of tuberculosis when such proficiency is intended to reproduce laboratory routine.

Keywords: Tuberculosis; Microscopy; Reproducibility of results.

Objective: To evaluate the diagnostic accuracy of bronchoscopy in patients with clinical or radiological suspicion of tuberculosis who were unable to produce sputum or with negative sputum smear microscopy results. Methods: A prospective cross-sectional study involving 286 patients under clinical or radiological suspicion of having pulmonary tuberculosis and submitted to bronchoscopy-BAL and transbronchial biopsy (TBB). The BAL specimens were submitted to direct testing and culture for AFB and fungi, whereas the TBB specimens were submitted to histopathological examination. Results: Of the 286 patients studied, 225 (79%) were diagnosed on the basis of bronchoscopic findings, as follows: pulmonary tuberculosis, in 127 (44%); nonspecific chronic inflammation, in 51 (18%); pneumocystis, fungal infections, or nocardiosis, in 20 (7%); bronchiolitis obliterans organizing pneumonia, alveolites, or pneumoconiosis, in 14 (5%); lung or metastatic neoplasms, in 7 (2%); and nontuberculous mycobacterium infections, in 6 (2%). For the diagnosis of tuberculosis, BAL showed a sensitivity and a specificity of 60% and 100%, respectively. Adding the TBB findings significantly increased this sensitivity (to 84%), as did adding the post-bronchoscopy sputum smear microscopy results (total sensitivity, 94%). Minor post-procedure complications occurred in 5.6% of the cases. Conclusions: Bronchoscopy is a reliable method for the diagnosis of pulmonary tuberculosis, with low complication rates. The combination of TBB and BAL increases the sensitivity of the method and facilitates the differential diagnosis with other diseases.

Keywords: Bronchoscopy; Tuberculosis, pulmonary; Sputum; Bronchoalveolar lavage; Biopsy.

Objective: To determine the demographic and clinical characteristics of patients with non-small cell lung cancer (NSCLC), as well as their disease course, by age group and gender. Methods: This was a retrospective cohort study of patients diagnosed with NSCLC from 2000 to 2012 and followed until July 2015 in a tertiary referral hospital in the city of São Paulo, Brazil. Based on the 25th and 75th percentiles of the age distribution, patients were stratified into three age groups: < 55 years; ≥ 55 and < 72 years; and ≥ 72 years. Survival time was evaluated during the follow-up period of the study. Functions of overall and gender-specific survival stratified by age groups (event: all-cause mortality) were calculated using the Kaplan-Meier method. Differences among survival curves were assessed via the log-rank test. Results: We included 790 patients with the following age distribution: < 55 years, 165 patients; ≥ 55 and < 72 years, 423; and ≥ 72 years, 202. In the entire sample, there were 493 men (62.4%). Adenocarcinoma was the most common histological pattern in the < 72-year age groups; 575 patients (73%) presented with advanced disease (stages IIIB-IV). The median 5-year survival was 12 months (95% CI: 4-46 months), with no significant differences among the age groups studied. Conclusions: NSCLC remains more common in men, although we found an increase in the proportion of the disease in women in the < 55-year age group. Adenocarcinoma predominated in women. In men, squamous cell carcinoma predominated in the ≥ 72-year age group. Most patients presented with advanced-stage disease at diagnosis. There were no statistical differences in survival between genders or among age groups.

Keywords: Lung neoplasms; Age groups, Sex; Survival.

Background: Lung cancer is the leading cause of cancer-related death worldwide. Objective: To determine the time spent diagnosing, staging and surgically treating lung cancer in a university hospital. Method: Between January 1990 and December 1998, 69 (53 male, 16 female) patients were diagnosed with lung cancer and underwent surgery. The hospital records of these patients were reviewed to evaluate clinical and histological data, dates of outpatient visits, hospital admission, tests and procedures, as well as to determine if the patients were examined as inpatients or as outpatients. Results: The 15 patients investigated as outpatients were designated as group I, the 28 examined as both inpatients and outpatients as group II, and the 26 investigated as inpatients as group III. Age ranged from 43 to 79 years (mean ± SD; 61 ± 10). Of the 69 patients, 43 were smokers and 23 were ex-smokers. The mean time from onset of symptoms to the first outpatient visit was 110 days and 33 days from the first outpatient visit until diagnosis. There was a lapse of 25 days between diagnosis and surgery. The mean total elapsed time between the first outpatient visit and surgery was 58 days. The mean total time was 72 days for group I, 72 days for group II, and 35 days for group III (p < 0.01). There was no significant difference regarding total time in relation to the different stages of the disease (p = 0.16). Conclusions: The results show that patients waited too long before seeking medical assistance and that medical treatment of lung cancer was further delayed when patients were examined in an outpatient setting.

Keywords: Lung neoplasm/surgery. Disease progression.

Hypersensitivity pneumonitis is an immunologic lung disease caused by chronic inhalation of chemicals or organic dusts. Its chronic stage makes diagnosis more difficult because other interstitial diseases share the same clinical and radiological presentation, usually requiring open lung biopsy to confirm the diagnosis. The authors reviewed the confirmed cases in the last 11 years at the Thoracic Diseases Institute [Instituto de Doenças do Tórax] of the Rio de Janeiro Federal University [UFRJ]. In this period, eight cases were confirmed by histopathological studies. Main symptoms were dyspnea and coughing. All cases showed interstitial infiltrates on radiological studies and restrictive functional patterns were found in 70% of the cases. All seven patients treated with corticosteroids responded with improved clinical symptoms, although some did not have radiological or functional response. Once the diagnosis is established, patients must avoid the causative environment because the disease may progress to fibrosis if exposition continues.

Keywords: Extrinsic allergic alveolitis. Case-control studies. Diagnosis.

Organizing pneumonia, whether or not accompanied by bronchiolitis obliterans, is a specific anatomicopathological condition of the lungs that can present in a variety of clinical and radiographic ways. It can be either idiopathic or secondary to a number of diseases, including infection and drugs. Objectives: To describe the clinical manifestations, radiographic and spirometric data seen in patients with organizing pneumonia. Methods: Retrospective analysis of patients with a diagnosis of organizing pneumonia. Results: 38 patients were included in the analysis. Fourteen also had clinical conditions related to organizing pneumonia, and they presented more frequently with diffuse pulmonary infiltrates (three of four cases) and associated bronchiolitis obliterans (57% vs. 20%, p = 0,05). Of the 13 patients with bronchiolitis obliterans, only one was asymptomatic and two had localized lesions (15%). Of the eight asymptomatic patients with localized lesions, no one had associated bronchiolitis obliterans, and the radiographic appearance often resembled bronchial carcinoma. Spirometry was generally of little value to diagnosis, probably because of the high prevalence of smoking in the sample. Conclusion: The clinical and radiographic presentation of organizing pneumonia is variable. Factors that suggest the absence of coexisting bronchiolitis obliterans are the absence of symptoms and localized radiographic lesions, and this form of the disease has to be more often differentiated from bronchial carcinoma in clinical practice.

Carcinoma of the lung can present in a number of guises and a number of possible and often complementary diagnostic approaches are available. The choice of procedure should reflect the presentation of the tumor, local expertise, intended management and patient preference. There are different methods of investigation: sputum cytology, fiberbronchoscopy, transbronchial biopsy, transbronchial needle aspiration, transthoracic fine needle aspiration, etc. The association of all of these methods increases the power of diagnosis. Staging is the measurement of the anatomical extent of a tumor in any given patient. The staging of cancer began with Denoix's TNM classification system, and, although several modifications were developed, it remains the basis of lung cancer staging systems up to now. Assigning patients to a particular TNM stage allows choosing the most appropriate therapy and provides prognostic information. Also, the impact of new therapeutic methods can be evaluated for efficacy and a comparison of the expected survival rates can be predicted.