Diffuse cystic lung diseases are characterized by cysts in more than one lung lobe, the cysts originating from various mechanisms, including the expansion of the distal airspaces due to airway obstruction, necrosis of the airway walls, and parenchymal destruction. The progression of these diseases is variable. One essential tool in the evaluation of these diseases is HRCT, because it improves the characterization of pulmonary cysts (including their distribution, size, and length) and the evaluation of the regularity of the cyst wall, as well as the identification of associated pulmonary and extrapulmonary lesions. When combined with clinical and laboratory findings, HRCT is often sufficient for the etiological definition of diffuse lung cysts, avoiding the need for lung biopsy. The differential diagnoses of diffuse cystic lung diseases are myriad, including neoplastic, inflammatory, and infectious etiologies. Pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, lymphocytic interstitial pneumonia, and follicular bronchiolitis are the most common diseases that produce this CT pattern. However, new diseases have been included as potential determinants of this pattern.

Keywords: Cysts; Diagnosis, differential; Lung diseases, interstitial; Tomography, X-ray computed.

High-resolution computed tomography (HRCT) is the radiological imaging technique best suited to revealing changes in lung structure. Various HRCT findings, taken together, can represent typical patterns. These patterns, in conjunction with the anatomical distribution of findings and with clinical data, can narrow the differential diagnosis of diffuse interstitial lung disease and, in many cases, indicate the correct diagnosis with a high degree of accuracy. The most common HRCT patterns seen in cases of diffuse interstitial lung diseases are the nodular pattern, linear/reticular opacities, cystic lesions, ground-glass opacities and consolidations. This article reviews the correlations between HRCT patterns and pathologic findings, summarizing the most common causes, as well as detailing the methods of investigation employed in order to diagnose the most common types of chronic diffuse lung disease.

Keywords: Lung diseases, interstitial/pathology; Tomography, X-Ray computed; Diagnostic techniques, respiratory system.

The approach described below is an attempt to make order out of chaos for the pathologists dealing with diffuse lung disease and to provide radiologists some information about the histology of interstitial lung disease as it applies to HRCT. Obviously, the approach outlined is not applicable to all situations and many cases remain insoluble. Nevertheless, it does give the pathologist a framework within which interstitial lung disease can be assessed, and helps to develop a differential diagnosis histologically. The author thinks this approach also shows good correlation with many of the changes observed by the chest radiologist with HRCT of the lung. Recognizing an anatomic distribution may not necessarily be correlated with how a lesion is clinically viewed. For example, bronchiolocentricity is an important and prominent feature in hypersensitivity pneumonitis and respiratory bronchiolitis associated with interstitial lung disease, but neither is clinically considered an airway disease. The authors also make comments about transbronchial biopsy in opposition to open-lung biopsy in the pathologic assessment of difuse lung disease, although HRCT does provide information to the clinician to help select the most appropriate biopsy modality. Obviously, open-lung biopsy (and those retrieved by thoracoscopic techniques) offer more tissue and make it easier to observe anatomic distribution and reaction patterns. Nevertheless, transbronchial biopsies often include sufficient tissue (although fragmented) and the pathologist is able to mentally reconstruct the distribution and reaction pattern. Obviously, the changes assessed in transbronchial biopsy have to be individualized on a case-by-case basis, but it is surprising how often they are useful when carefully correlated with the clinical and radiological features in a given case.

Keywords: Pulmonary interstitial disorders. Pathology. Pulmonary fibrosis. Pulmonary biopsy.

Objective: To evaluate the role of video-assisted thoracoscopy in the diagnosis of diffuse parenchymal lung diseases. Methods: The medical charts of patients suspected of having diffuse parenchymal lung disease were retrospectively reviewed, as were the results of the anatomopathological examination of lung biopsy specimens collected through video-assisted thoracoscopy. Results: Of the 48 patients included in the study, 25 (52.08%) were female and 23 (47.92%) were male. The mean age was 58.77 years (range, 20-76 years). A total of 54 biopsy fragments were submitted to anatomopathological examination: 24 (44.44%) from the lingula; 10 (18.52%) from the left lower lobe; 7 (12.96%) from the right middle lobe; 6 (11.11%) from the right lower lobe; 5 (9.26%) from the left upper lobe; and 2 (3.71%) from the right upper lobe. The mean duration of thoracic drainage was 2.2 days. Adverse events included conversion to thoracotomy, in 2 patients (4.17%), and residual pneumothorax, in 1 (2.08%). The definitive diagnosis was made in 46 patients (95.83%), and idiopathic interstitial pneumonia was the predominant diagnosis (in 54.18%). The most common diagnoses were usual interstitial pneumonia (in 29.27%), nonspecific interstitial pneumonia (in 16.67%) and hypersensitivity pneumonia (in 12.50%). Conclusions: Lung biopsy through video-assisted thoracoscopy is a safe, effective and viable procedure for the diagnosis of diffuse parenchymal lung diseases.

Keywords: Lung diseases, interstitial; Thoracoscopy; Diagnosis.

Objective: To determine the interobserver and intraobserver agreement in the diagnosis of interstitial lung diseases (ILDs) based on HRCT scans and the impact of observer expertise, clinical data and confidence level on such agreement. Methods: Two thoracic radiologists and two general radiologists independently reviewed the HRCT images of 58 patients with ILDs on two distinct occasions: prior to and after the clinical anamnesis. The radiologists selected up to three diagnostic hypotheses for each patient and defined the confidence level for these hypotheses. One of the thoracic and one of the general radiologists re-evaluated the same images up to three months after the first readings. In the coefficient analyses, the kappa statistic was used. Results: The thoracic and general radiologists, respectively, agreed on at least one diagnosis for each patient in 91.4% and 82.8% of the patients. The thoracic radiologists agreed on the most likely diagnosis in 48.3% (κ = 0.42) and 62.1% (κ = 0.58) of the cases, respectively, prior to and after the clinical anamnesis; likewise, the general radiologists agreed on the most likely diagnosis in 37.9% (κ = 0.32) and 36.2% (κ = 0.30) of the cases. For the thoracic radiologist, the intraobserver agreement on the most likely diagnosis was 0.73 and 0.63 prior to and after the clinical anamnesis, respectively. That for the general radiologist was 0.38 and 0.42.The thoracic radiologists presented almost perfect agreement for the diagnostic hypotheses defined with the high confidence level. Conclusions: Interobserver and intraobserver agreement in the diagnosis of ILDs based on HRCT scans ranged from fair to almost perfect and was influenced by radiologist expertise, clinical history and confidence level.

Keywords: Lung diseases, interstitial; Tomography, X-ray computed; Observer variation.

Sclerosing mediastinitis is a rare disorder characterized by an extensive fibrotic reaction involving the mediastinum. Due to the compression or invasion of mediastinal structures, the disorder mimics neoplasia. We present three cases of superior vena cava syndrome in which sclerosing mediastinitis was confirmed. The pathophysiological process is related to enlarged mediastinal lymph nodes, fibroblast proliferation and collagen deposition. The main causes of sclerosing mediastinitis are histoplasmosis and tuberculosis, both of which are prevalent in Brazil. It is difficult to make an accurate histopathological diagnosis using minimally invasive methods, and there is no effective treatment for this condition. In order to make a definitive diagnosis and resolve the aerodigestive tract obstruction, exploratory surgery is indicated.

Keywords: Mediastinitis/physiopathology; Mediastinum; Pulmonary fibrosis; Mediastinal neoplasms; Diagnosis, differential; Case reports [Publication type].

We present the case of a 60-year-old female patient who had been in menopause for 14 years and presented a pulmonary nodule on chest X-ray diagnosed in the postoperative follow-up evaluation of breast cancer. The patient had a history of mastectomy and ipsilateral axillary lymphadenectomy for invasive ductal breast carcinoma, as well as of hormone therapy, chemotherapy, and adjuvant radiotherapy. After thoracoscopic nodulectomy, the frozen section analysis revealed a pulmonary hamartoma. Recent studies show that 75% of patients who undergo surgery for pulmonary nodules after a curative mastectomy for breast cancer present lung metastases, 11.5% present primary lung cancer, and 13.5% present benign lesions, including hamartoma.

Keywords: Hamartoma; Breast neoplasms; Lung neoplasms; Neoplasm metastasis.

Intimal sarcoma of the pulmonary artery is a rare and potentially lethal tumor, the diagnosis of which is difficult and therefore frequently delayed. The clinical signs and symptoms are nonspecific, often mimicking chronic pulmonary thromboembolism (CPTE). We report the case of a 45-year-old male under treatment for CPTE associated with pulmonary arterial hypertension and chronic cor pulmonale. There was no response to treatment with anticoagulants and sildenafil. We emphasize the difficulties in diagnosing intimal sarcoma of the pulmonary artery, the need to investigate this neoplasm in the differential diagnosis of CPTE and the systematic use of criteria for the appropriate prescription of new medications for pulmonary artery hypertension.

Keywords: Pulmonary embolism; Hypertension, pulmonary; Hemangiosarcoma; Diagnosis, differential.

Munchhausen syndrome results from a psychiatric disorder in which patients attempt to demonstrate signs and symptoms of serious organic diseases. In a review of the literature, we found 23 cases of Munchhausen syndrome accompanied by factitious hemoptysis, 2 presenting the same mechanism described herein. We report the case of a 23-year-old male with a recent history of multiple hospital admissions for investigation of bloody sputum, although no conclusive diagnosis had been made. Upon insistent questioning the patient admitted to aspirating his own blood with a syringe, holding it in his mouth and eliminating it in order to simulate hemoptysis. Munchhausen syndrome should be considered in patients presenting hemoptysis of obscure etiology.

Keywords: Munchhausen syndrome. Factitious hemoptysis. Diagnosis

Interstitial lung diseases (ILDs) in children constitute a heterogeneous group of rare diseases that have been described and classified according to experiences and research in adults. However, pediatric pulmonologists have observed that the clinical spectrum is broader in children than in adults, and that many of these disorders have different courses and treatment responses. In addition, probably due to the various stages of lung development and maturation, new clinical forms have been described, particularly in infants. This has broadened the classification of ILDs in this age bracket. The understanding that neither the usual definition nor the standard classification of these disorders entirely apply to children has prompted multicenter studies designed to increase knowledge of these disorders, as well as to standardize diagnostic and therapeutic strategies. We have reviewed the conceptualization of ILDs in children, taking into consideration the particularities of this group of patients when using the criteria for the classification of these diseases in adults. We have also made a historical review of several multicenter studies in order to further understanding of the problem. We have emphasized the differences in the clinical presentation, in an attempt to highlight knowledge of newly described entities in young children. We underscore the need to standardize management of laboratory and radiological routines, as well as of lung biopsy processing, taking such knowledge into account. It is important to bear in mind that, among the recently described disorders, genetic surfactant dysfunction, which is often classified as an idiopathic disease in adults, should be included in the differential diagnosis of ILDs.

Keywords: Lung diseases, interstitial; Lung diseases, interstitial/diagnosis; Lung diseases, interstitial/therapy; Child.

Cystic fibrosis (CF) is an autosomal recessive genetic disorder characterized by dysfunction of the CFTR gene. It is a multisystem disease that most often affects White individuals. In recent decades, various advances in the diagnosis and treatment of CF have drastically changed the scenario, resulting in a significant increase in survival and quality of life. In Brazil, the current neonatal screening program for CF has broad coverage, and most of the Brazilian states have referral centers for the follow-up of individuals with the disease. Previously, CF was limited to the pediatric age group. However, an increase in the number of adult CF patients has been observed, because of the greater number of individuals being diagnosed with atypical forms (with milder phenotypic expression) and because of the increase in life expectancy provided by the new treatments. However, there is still great heterogeneity among the different regions of Brazil in terms of the access of CF patients to diagnostic and therapeutic methods. The objective of these guidelines was to aggregate the main scientific evidence to guide the management of these patients. A group of 18 CF specialists devised 82 relevant clinical questions, divided into five categories: characteristics of a referral center; diagnosis; treatment of respiratory disease; gastrointestinal and nutritional treatment; and other aspects. Various professionals working in the area of CF in Brazil were invited to answer the questions devised by the coordinators. We used the PubMed database to search the available literature based on keywords, in order to find the best answers to these questions.

Keywords: Cystic fibrosis/diagnosis; Cystic fibrosis/therapy; Cystic fibrosis/complications; Practice guideline.

A 35 year-old black woman, previously healthy, who complained about chronic cough and shortness of breath was investigated after non-response of symptoms. Her chest X-ray and high resolution chest CT-scan were normal. She presented with abnormal spirometry, a mild restrictive disturbance. After a negative initial clinical investigation, an open lung biopsy was indicated. Multiple microscopic peribronchiolar tumorlets carcinoids - neuroendocrine cell hyperplasia was revealed. The authors emphasize the importance of an early diagnosis of this unusual entity and discuss its possible pathophysiological mechanisms.

Keywords: Lung diseases. Neuroendocrine cell. Bronchiolitis. Carcinoid. Tumorlets.

Background: Open lung biopsy is regarded as the gold standard for the diagnosis of diffuse pulmonary infiltrates. Objective: To determine the diagnostic yield, therapeutic changes, complications and mortality attributed to open lung biopsy in patients with diffuse pulmonary infiltrates and on mechanical ventilation. Method: We reviewed, retrospectively, the charts of 24 patients, ranging from 26 to 89 years of age, admitted to the intensive care units of two private hospitals and submitted to open lung biopsy. Results: Diagnostic positivity was found in 100% of patients, resulting in an alteration in the treatment regimen in 75%. Postoperative complications occurred in five patients (20.8%). There were no biopsy-related deaths, although global mortality was 45.8%. Conclusion: Open lung biopsy is a safe and high yield procedure for diagnosing diffuse pulmonary infiltrate in patients on mechanical ventilation. Despite the fact that no mortality impact factor has been assigned to such patients, data in the literature regarding prognosis must be taken into consideration.

Keywords: Biopsy. Respiratory insufficiency. Respiration artificial.

Macrolides are drugs that have antimicrobial effects, especially against intracellular pathogens. Various studies have shown that macrolides might also have anti-inflammatory effects. Macrolides inhibit the production of interleukins and can reduce pulmonary neutrophilic inflammation. Clinical trials have demonstrated beneficial effects of macrolides in various chronic lung diseases. The objective of this study was to review recent data in the medical literature on the anti-inflammatory effects of macrolides in childhood lung diseases by searching the Medline (PubMed) database. We used the following search terms: "macrolide and cystic fibrosis"; "macrolide and asthma"; "macrolide and bronchiolitis obliterans"; and "macrolide and acute bronchiolitis". We selected articles published in international scientific journals between 2001 and 2012. Clinical studies and in vitro evidence have confirmed the anti-inflammatory effect of macrolides in respiratory diseases. Some clinical trials have shown the benefits of the administration of macrolides in patients with cystic fibrosis, although the risk of bacterial resistance should be considered in the analysis of those benefits. Such benefits are controversial in other respiratory diseases, and the routine use of macrolides is not recommended. Further controlled clinical trials are required in order to assess the efficacy of macrolides as anti-inflammatory drugs, so that the benefits in the treatment of each specific clinical condition can be better established.

Keywords: Macrolides; Asthma; Cystic Fibrosis; Bronchiolitis.