Rosai-Dorfman disease (RDD) consists of sinus histiocytosis with massive lymphadenopathy. Extranodal involvement occurs in up to 43% of cases. However, isolated soft tissue RDD is rare. Isolated mediastinal RDD is exceedingly rare, and there have been only three previous reports. Involvement of the posterior mediastinum in RDD has been reported only in the context of disseminated RDD. Here, we report the case of a 49-year-old female patient with a two-year history of cervical pain and lymphadenomegaly, which resolved spontaneously. A CT scan revealed a left paravertebral mass with a diameter of 6 cm. The patient was submitted to surgical excision of the mass. Microscopic examination and immunophenotyping of the surgical specimen led to a diagnosis of RDD. During a 12-month follow-up period, the patient complained of mild cough and chest pain. Periodic imaging tests showed no sign of recurrence, and no postoperative cervical lymphadenomegaly was detected.

Keywords: Histiocytosis, sinus; Soft tissue neoplasms; Mediastinal neoplasms; Mediastinum.

Benign schwannoma tumors are the most common primary tumors of the posterior mediastinum. They may develop into a dumbbell-shaped involvement of the medullar channel, but rarely reach the tracheobronchial tree. The authors report a case of a 45-year-old female patient with a benign schwannoma in the posterior mediastinum, with a dumbbell-shaped lesion that traverses the intercartilaginous septa of the trachea. The tumor was resected by endoscopy in the endotracheal portion and afterwards by thoracotomy of the mediastinal tumor. Eight months after the surgery, there has been no recurrence of the lesion.

Keywords: Mediastinal neoplasms. Thoracotomy. Thoracoscopy. Mediastinal cyst.

Cystic lymphangioma is a rare congenital benign tumor. It results from focal proliferation of well-differentiated lymphatic tissue originating from abnormal development of the lymphatic system. Most cystic lymphangiomas occur in the primitive lymph sacs of children or young adults. They generally appear in the neck (75%) and axillary region (20%). Only 1% are located in the mediastinum. Acquired lymphangiomas, which are principally seen in middle-aged adults, are caused by a process of chronic lymphatic obstruction secondary to surgery, chronic infection, or radiation. Here, we present the case of a 50-year-old male with cystic lymphangioma of the mediastinum, detected on a routine chest X-ray.

Keywords: Lymphangioma, cystic; Mediastinum; Incidental findings.

A 30 year old Caucasian male from São Paulo was admitted to the hospital He had been complaining about constant, moderate pain in the anterior and lateral left hemi-thoracic region for the last three months as well as associated great effort dyspnea over the last month.Investigation with chest X-rays, CT scans and MRI revealed a large anterior and medial mediastinal tumor suggesting large vessel invasion. The patient was submitted to a left side parasternal mediastinostomy and a biopsy of the mediastinal mass which was complicated by severe bleeding. An immediate median full sternotomy was elected in addition to a left anterior-lateral thoracotomy for total tumor resection and control of the bleeding. Evolution was good, with hospital discharge on the ninth postoperative day. The anatomical-pathological essay disclosed a hemangioendothelioma of the mediastinum.

Keywords: Hemangioendothelioma/diagnosis. Mediastinal neoplasms.

The mediastinum, made up by many organs and structures, comprises a wide range of affections, from simple cysts to low differentiated neoplasias and lymphomas. In their day-to-day activities, the diagnosis of these affections represent a real challenge to the pathologists. Furthermore, one of the main approaches to diagnosis includes mediastinoscopy. Therefore, the representation of the specimen for studies, as well as some artifacts to obtain the specimen, may pose some difficulty for a final diagnosis. This article will focus mainly on the problems faced to diagnose entities from the specimens obtained by mediatinoscopy in the surgical room, during the extraction of the material and at examination by freezing. The article will also update current criteria used to classify the tumors and the use of the immunohistochemistry to complement the diagnosis, criteria of invasion, and metastases. The purposes of this article are: recognize the main affections of the mediastinum, classify the main tumors, apply malignancy criteria, identify prognostic markers, and evaluate when there is need to establish a clinical, radiological and morphological correlation.

Keywords: Mediastinum. Mediastinum pathology. Prognostic markers.

Ectopic thyroid is a rare condition, and its location in the anterior mediastinum is even rarer, there having been only 5 reported cases in the past 30 years. Here, we describe 2 clinical cases and present a review of the literature regarding the etiology, embryology and clinical manifestations of ectopic thyroid.

Keywords: Thyroid dysgenesis; Mediastinum; Goiter.

Objective: To evaluate the impact of an aggressive treatment approach using muscle flaps or omentopexy in infections of the sternum and anterior mediastinum following sternotomy on mortality, as compared to that of a conservative treatment approach. Methods: Data were collected prior to, during and after the surgical procedures. Group A (n = 44) included patients submitted to conservative treatment- debridement together with resuture or continuous irrigation with polyvinylpyrrolidone-iodine solutions, or even with second-intention wound healing (retrospective data). Group B (n = 9) included patients in whom infection was not resolved with conservative treatment, and who therefore underwent aggressive treatment (intermediate phase). Group C (n = 28) included patients primarily submitted to aggressive treatment (prospective data). Results: Postoperative hospital stays were shorter in the patients submitted to aggressive treatment (p < 0.046). There were 7 deaths in group A, 1 in group B, and 2 in group C. However, the classical level of significance of α = 0.05 was not reached. Conclusion: Aggressive treatment also proved to be effective when the infection was not resolved with conservative treatment. These findings demonstrate that the proposed treatment provides excellent results.

Keywords: Surgical flaps; Osteomyelitis; Mediastinitis; Thoracic surgery.

Objective: Video-assisted thoracoscopic surgery (VATS) has been a surgical intervention of choice for the treatment of spontaneous pneumothorax (SP) with lung bulla. Our objective was to introduce a uniportal VATS approach for simultaneous bilateral bullectomy and to evaluate its therapeutic efficacy. Methods: Between May of 2011 and January of 2012, five patients underwent bilateral bullectomy conducted using this approach. All of the patients presented with bilateral SP. Preoperative HRCT revealed that all of the patients had bilateral apical bullae. We reviewed the surgical indications, surgical procedures, and outcomes. Results: All of the patients were successfully submitted to this approach for bilateral bullectomy, and there were no intraoperative complications. The median time to chest tube removal was 4.2 days, and the median length of the postoperative hospital stay was 5.2 days. The median postoperative follow-up period was 11.2 months. One patient experienced recurrence of left SP three weeks after the surgery and underwent pleural abrasion. Conclusions: Bilateral bullectomy through uniportal VATS combined with contralateral access to the anterior mediastinum is technically reliable and provides favorable surgical outcomes for patients with bilateral SP who develop bilateral apical bullae. However, among other requirements, this surgical procedure demands that surgeons be experienced in VATS and that the appropriate thoracoscopic instruments are available.

Keywords: Pneumothorax; Thoracic surgery, video-assisted; Pleural cavity; Mediastinum.

Objective: This study aimed to investigate acute and chronic effects of varenicline on lung tissue in an experimental study. Methods: A total of 34 rats were randomly allocated into study (varenicline) and control groups. The rats were divided into two groups (i) control group, (ii) varenicline group. Then, the rats in the each group were sub‑divided equally in turn as acute (C1; V1) and chronic (C2; V2) ; all rats of acute and chronic groups were sacrificed under the anesthesia on the 45th day for acute group [C1 (n=5) and V1 (n=12)] and the 90th day for chronic group [C2 (n=5) and V2 (n=12)], respectively. Thus, biochemical and histopathological analysis were carried out. Results: Thirty four rats completed the study, 24 were in varenicline group and 10 were in control group. In chronic exposure to varenicline, oxidant levels comprising of malondialdehyde (MDA), and myeloperoxidase (MPO) increased and superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx) levels, named as antioxidants, decreased significantly when compared to the control group. MDA and MPO levels were also significantly higher and SOD, CAT, GPx, GSH levels were also significantly lower in chronic varenicline group when compared to acute varenicline group. These findings were also supported by histopathological observations. Conclusion: This is the first study, which evaluated pulmonary effects of varenicline experimentally on an animal model. It was observed that chronic varenicline treatments cause inflammation and lung cell injury.

Keywords: Varenicline; Lung tissue; Oxidative stress; Pulmonary toxicity.

Connective tissue disease-associated interstitial lung disease (CTD-ILD) represents a group of systemic autoimmune disorders characterized by immune-mediated organ dysfunction. Systemic sclerosis, rheumatoid arthritis, idiopathic inflammatory myositis, and Sjögren's syndrome are the most common CTDs that present with pulmonary involvement, as well as with interstitial pneumonia with autoimmune features. The frequency of CTD-ILD varies according to the type of CTD, but the overall incidence is 15%, causing an important impact on morbidity and mortality. The decision of which CTD patient should be investigated for ILD is unclear for many CTDs. Besides that, the clinical spectrum can range from asymptomatic findings on imaging to respiratory failure and death. A significant proportion of patients will present with a more severe and progressive disease, and, for those, immunosuppression with corticosteroids and cytotoxic medications are the mainstay of pharmacological treatment. In this review, we summarized the approach to diagnosis and treatment of CTD-ILD, highlighting recent advances in therapeutics for the various forms of CTD.

Keywords: Lung diseases, interstitial; Collagen diseases; Scleroderma, systemic; Arthritis, rheumatoid; Myositis; Therapeutics.

The initial evaluation of patients with interstitial lung disease (ILD) primarily involves a comprehensive, active search for the cause. Autoantibody assays, which can suggest the presence of a rheumatic disease, are routinely performed at various referral centers. When interstitial lung involvement is the condition that allows the definitive diagnosis of connective tissue disease and the classical criteria are met, there is little debate. However, there is still debate regarding the significance, relevance, specificity, and pathophysiological role of autoimmunity in patients with predominant pulmonary involvement and only mild or benign symptoms of connective tissue disease. The purpose of this article was to review the current knowledge of autoantibody positivity and to discuss its possible interpretations in patients with ILD and without clear etiologic associations, as well as to enhance the understanding of the natural history of an allegedly new disease and to describe the possible prognostic implications. We also discuss the proposition of a new term to be used in the classification of ILDs: lung-dominant connective tissue disease.

Keywords: Idiopathic interstitial pneumonias; Autoantibodies; Connective tissue diseases; Autoimmune diseases; Diagnosis, differential.

Objective: To evaluate the pulmonary alterations of animals with Hepatopulmonary Syndrome (HPS) submitted to Biliary Duct Ligature (BDL), as well as the antioxidant effect of Melatonin (MEL). Methods: Sixteen male Wistar rats, divided into four Sham groups: BDL group, Sham + MEL group and BDL + MEL. The pulmonary and hepatic histology, lipoperoxidation and antioxidant activity of lung tissue, alveolar-arterial O2 difference and lung / body weight ratio (%) were evaluated. Results: When comparing the groups, could be observed an increase of vasodilation and pulmonary fibrosis in the BDL group and the reduction of this in relation to the BDL + MEL group. It was also observed significant changes in the activity of catalase, ApCO2, ApO2 in the LBD group when compared to the other groups. Conclusion: The use of MEL has been shown to be effective in reducing vasodilation, fibrosis levels and oxidative stress as well as gas exchange in an experimental HPS model.

Keywords: Bile duct; Hepatopulmonary Syndrome; Melatonin; Lung.

Acute respiratory distress syndrome (ARDS) is characterized by diffuse alveolar damage, and evolves progressively with three phases: exsudative, fibroproliferative, and fibrotic. In the exudative phase, there are interstitial and alveolar edemas with hyaline membrane. The fibroproliferative phase is characterized by exudate organization and fibroelastogenesis. There is proliferation of type II pneumocytes to cover the damaged epithelial surface, followed by differentiation into type I pneumocytes. The fibroproliferative phase starts early, and its severity is related to the patient's prognosis. The alterations observed in the phenotype of the pulmonary parenchyma cells steer the tissue remodeling towards either progressive fibrosis or the restoration of normal alveolar architecture. The fibrotic phase is characterized by abnormal and excessive deposition of extracellular matrix proteins, mainly collagen. The dynamic control of collagen deposition and degradation is regulated by metalloproteinases and their tissular regulators. The deposition of proteoglycans in the extracellular matrix of ARDS patients needs better study. The regulation of extracellular matrix remodeling, in normal conditions or in several pulmonary diseases, such as ARDS, results from a complex mechanism that integrate the transcription of elements that destroy the matrix protein and produce activation/inhibition of several cellular types of lung tissue. This review article will analyze the ECM organization in ARDS, the different pulmonary parenchyma remodeling mechanisms, and the role of cytokines in the regulation of the different matrix components during the remodeling process.

Keywords: Respiratory distress syndrome. Pulmonary alveoli/lesions. Extracellular matrix. Cytokines/ultrastructure.