Mediastinum (Hong Kong, China)最新文献

Background: Robot-assisted thoracic surgery (RATS) for intrathoracic pathology and especially for mediastinal mass resection has been increasingly accepted as an alternative method to open sternotomy and video-assisted thoracic surgery (VATS). However, the utilization of this approach for complex and advanced in size cases needs more clinical evidence. We are presenting a series of 4 patients who had resection of >10 cm mediastinal masses via RATS.

Cases description: The mean age was 76.25±10.3 years and 3 were males (75%). All masses were positron emission tomography (PET) positive, and 1 patient had positive Acetyl-cholinesterase antibodies and myasthenia gravis (MG). All patients underwent RATS resection via DaVinci^® X system. The dissections were conducted with spatula and/or Maryland bipolar forceps. In 2 cases, the resection was done with bilateral docking, and in 1 case, a drain was not inserted at the end. In 1 patient, pericardial resection was necessitated. All masses were thymomas with 1 dimension measured >10 cm on pathology. All patients were discharged on day 1 or 2 postoperatively with uneventful recoveries. There was no in-hospital, 30- or 90-day mortality. All patients were found to be without issues on follow-up.

Conclusions: This report shows that RATS is safe and can be offered in the management of >10 cm anterior mediastinal masses. The previous size limit of the tumor for minimally invasive and especially RATS approach of 5 cm should be challenged.

Background: The most common thymic tumours, thymomas, are derived from thymic epithelium and are generally low-grade neoplasm. Frankly malignant tumours, thymic carcinomas are rarer still. Exceedingly rare thymic tumours contain a mesenchymal tissue component such as fibrous connective tissue and/or mature fat. Lipofibroadenoma (LFA) is a very rare mixed epithelial-mesenchymal thymic tumour, included in the category of thymic epithelial tumors. LFA in addition to a mature adipocytic component, contains variable epithelial and mesenchymal tissue components. Owing to the presence of an epithelial component in LFA, this entity, in contrast to thymolipoma, is included in the World Health Organization (WHO) category of thymic epithelial neoplasm. Currently only 12 LFA cases have been described. The 12 previously reported cases all behaved in a benign fashion, although four cases were associated with a conventional type of thymoma. We here present a new, 13th, case of LFA.

Case description: The LFA was discovered incidentally in a previously healthy 17-year-old male after investigations for suspected pneumonia. On imaging a mass was discovered in the anterior mediastinum which was subsequently surgically removed. The resected tumour was extensively investigated, including the first instance of full molecular analysis of this rare entity and all available literature on LFA was sourced to provide a comprehensive overview. The histology of this LFA was similar to previously described cases. No gene mutations or rearrangements were identified. The patient made an uneventful recovery and after 13 months of follow-up remained well.

Conclusions: An additional, 13th case of LFA is presented. Based on the available literature it appears that LFA may be considered a benign composite thymic tumour, although the combination of an additional conventional thymoma component may warrant closer follow-up.

Central airway obstruction (CAO) is a debilitating condition with a significant impact on patient's quality of life and risk of hospitalization from respiratory failure. The causes of CAO can be both benign and malignant. Benign CAO may be idiopathic or secondary to other disease processes (infection, intubation, tracheostomy, etc.). Malignant central airway obstruction (MCAO) may occur in patients with primary lung malignancy as well as metastasis from other malignancies including renal cell, colon, and breast. In a cohort review, MCAO was found in up to 13% of patients with newly diagnosed lung cancer. The obstruction may occur either due to endoluminal disease, extrinsic compression, or a combination of both. Several bronchoscopic tools are available to manage such obstruction. Practice patterns and tools used to relieve CAO vary between institutions and may depend on physician preference, patient characteristics, emergency nature of the procedure, and nature of the obstruction. To quantify the effect and added value of such interventions, it is crucial to understand the clinical impact these interventions have on patients. The clinical impact of therapeutic bronchoscopy (TB) must then be weighed against the potential complications to justify its value. Early studies of TB for CAO included patients with both malignant and benign etiologies. The study population's heterogeneity makes it difficult to determine how TB affects clinical outcomes, as clinical outcomes are disease specific. The impact of TB for a MCAO may be different when compared to a benign CAO. Similarly, the clinical outcome of treating an idiopathic benign CAO may be different than that of a post tracheostomy airway obstruction. In this article, we will focus on the clinical outcomes of TB in MCAO. TB has been shown to have a clear impact on weaning from mechanical ventilation, dyspnea, health-related quality of life, survival and quality adjusted survival. The potential impact of TB on these outcomes should be weighed against the potential risk of complications. Understanding the factors associated with improved clinical outcomes will help physicians decide when and if TB is helpful. Future studies should focus on creating a decision analysis tool to further define decision thresholds.

The mediastinum is the central compartment in the thoracic cavity that lies between the lungs. It extends from the thoracic inlet superiorly to the diaphragm inferiorly and sternum anteriorly to the vertebral column posteriorly. It is commonly divided into four compartments-superior, anterior, middle and posterior mediastinum. However, some have started to classify it into the more recent three compartments-anterior (prevascular), middle (visceral) and posterior (paravertebral). The mediastinum is of clinical significance because many vital structures, such as the heart, great vessels, esophagus, lymphatics, and trachea, lie within these compartments. Disease presentation can greatly vary depending on the structures involved, and the differential diagnosis can range widely. Therefore, knowledge of the anatomy and subdivisions of the mediastinum is vital for thoracic surgeons. Herein, we have provided a brief review of the mediastinal anatomy. Utilizing the four-compartment model, we detail the contents of each compartment of the mediastinum with special attention to its veins and nerves. There are also several venous junctions that are important for mediastinal surgery, such as the internal jugular-subclavian venous junction and the left-right brachiocephalic venous junction. We describe useful superficial landmarks, such as the sternocleidomastoid and manubrium, and how they relate to some of the key venous junctions.

A wide variety of neoplastic and nonneoplastic conditions occur in the mediastinum. Imaging plays a central role in the evaluation of mediastinal pathologies and their mimics. Localization of a mediastinal lesion to a compartment and characterization of morphology, density/signal intensity, enhancement, and mass effect on neighboring structures can help narrow the differentials. The International Thymic Malignancy Interest Group (ITMIG) established a cross-sectional imaging-derived and anatomy-based classification system for mediastinal compartments, comprising the prevascular (anterior), visceral (middle), and paravertebral (posterior) compartments. Cross-sectional imaging is integral in the evaluation of mediastinal lesions. Computed tomography (CT) and magnetic resonance imaging (MRI) are useful to characterize mediastinal lesions detected on radiography. Advantages of CT include its widespread availability, fast acquisition time, relatively low cost, and ability to detect calcium. Advantages of MRI include the lack of radiation exposure, superior soft tissue contrast resolution to detect invasion of the mass across tissue planes, including the chest wall and diaphragm, involvement of neurovascular structures, and the potential for dynamic sequences during free-breathing or cinematic cardiac gating to assess motion of the mass relative to adjacent structures. MRI is superior to CT in the differentiation of cystic from solid lesions and in the detection of fat to differentiate thymic hyperplasia from thymic malignancy.

Background: Based on the algorithm on preoperative mediastinal staging in patients with non-small cell lung cancer (NSCLC), endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is indicated in case of computed tomography (CT)-enlarged or positron emission tomography (PET)-positive mediastinal lymph nodes. It represents both a safe minimal invasive procedure with complication rates of less than 1.5% and a valid tool with a high sensitivity defining mediastinal nodal disease. However, infectious complications like mediastinitis or pyopericardium are most feared.

Case description: A 54-year-old woman was admitted to our hospital for further investigation of a suspected NSCLC of the right upper lobe. EBUS-TBNA was performed to receive both diagnosis and samples of the mediastinal lymph nodes. Two weeks after EBUS-TBNA, the patient presented with symptoms of cardiogenic/septic shock: hypotension, tachycardia, chest pain and fever. Prompt diagnosis of concomitant infectious mediastinitis and extensive pyopericardium in consequence of EBUS-TBNA was obvious. Besides systemic antibiotics, bilateral thoracoscopic interventions finally made the breakthrough. The patient could be discharged roughly three weeks after emergent re-admittance. As being finally diagnosed with NSCLC (stage IIIA squamous cell carcinoma), the patient underwent-subsequent to induction chemotherapy-a definitive sequential chemoradiotherapy. Twelve-month follow-up confirmed stable disease.

Conclusions: It is to be expected that with increasing application of EBUS-TBNA as mediastinal staging tool, the number of serious infection-related complications will rise accordingly. The efficacy of antibiotic prophylaxis after EBUS-TBNA has not yet been proved and is therefore not included in any guideline. Our case gives an impression on the severity of delayed infectious complications after EBUS-TBNA and outlines up-front surgery as primary objective to broadly debride all contagious abscess-/empyema sites. With increased use of EBUS-TBNA as mediastinal staging tool, clinicians should be aware of this rare but highly critical peri-interventional complication in order to closely monitor endangered patients.

Esophageal duplication represents one of the most common types of bronchopulmonary foregut malformations. These rare congenital anomalies occur secondary to embryological aberrations between the 4th and 8th weeks of gestation. In order to be classified as an esophageal cyst a mediastinal cyst must have a close proximity with the esophagus, be lined by alimentary (squamous epithelium) or tracheobronchial mucosa and covered by two smooth muscle layers. These rare anomalies are often asymptomatic during adulthood. However, they can cause symptoms in early childhood, generally during the first 2 years of life. Variations in location, size, presence or absence of heterotopic mucosa, will dictate the clinical presentation. Dysphagia, food impaction, persistent cough and chest pain are common clinical presentations. Imaging studies including esophagram, computed tomography (CT) and magnetic resonance imaging (MRI) can provide key findings to reach the diagnosis. Nonetheless, endoscopic evaluation, particularly endoscopic ultrasound (EUS) is the most valuable tool to determine whether this lesion is cystic versus solid and or if there are abnormal mucosal findings. Needle biopsies are controversial but can help with drainage and to rule out malignant transformation. Therapeutic options include endoluminal drainage. However, more definitive therapies include surgical excision. Open and minimally invasive (laparoscopic and thoracoscopic) techniques have been demonstrated to be safe and effective at completely removing these lesions. Recently, robotic-assisted resections have gained more attention with case reports and series reporting excellent outcomes.

Background: The propensity of thymic cysts to mimic solid thymic epithelial tumors (TETs) on computed tomography (CT), on account of attenuation values greater than water and thickened or calcified walls, can lead to non-therapeutic thymectomy. These lesions can fluctuate in volume, CT attenuation, and magnetic resonance imaging (MRI) signal over time. We hypothesized that spontaneous hemorrhage and resorption may contribute to their variable appearance over time.

Methods: Completely excised thymic cysts were identified retrospectively over a 20-year period by their pathologic diagnosis. Cysts were excluded if they did not have available presurgical imaging, were not prevascular, were located within or contained an enhancing mass by imaging, or were of non-thymic origin upon microscopic review. Histopathological analysis of all available resected thymic cyst material and radiologic analysis of the cysts on pre-operative imaging were performed.

Results: Upon application of exclusion criteria, we identified 18 thymic cysts from the initial 85 mediastinal cystic specimens. Most cysts were unilocular (11/15, 73%), showed turbid-to-semisolid, hemorrhagic fluid (10/12, 83%) and showed histopathological findings suggestive of intralesional microbleeding (14/18, 78%), remodeling (8/18, 44%), pathological wound healing/scarring of the capsule (16/18, 89%), and fat necrosis in the surrounding thymic tissue (12/18, 67%). On CT, 6/17 (35%) cysts demonstrated wall calcification. Sixty-five percent (11/17) had attenuation values ≥20 Hounsfield units (HU). Two of the 4 cysts imaged by MRI were T1-isointense, one was mixed hyper- and isointense, and one T1-hypointense to muscle, with iso- and hyperintensity indicating hemorrhagic or proteinaceous content. Twenty-five percent (1/4) of cyst walls imaged by MRI were T1/T2-hypointense, indicating presence of calcification, hemosiderin, and/or fibrosis.

Conclusions: Resected thymic cysts in this cohort often showed features suggestive of intralesional microbleeding, inflammation, and fibrosis, which may explain their appearance and behavior over time on CT and MRI.