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Extended thymectomy is performed to excise the ectopic thymic tissue around the thymus; however, the distribution of the ectopic thymic tissue in the adipose tissue remains unclear. This study investigated the distribution of ectopic thymic tissue in extended thymectomy. This study included 31 patients who underwent extended thymectomy. Pathological specimens were reviewed to examine the distribution of ectopic thymic tissues in six locations: the right and left outer sides of the thymus tissue and the upper and lower ends of the resected tissue in extended thymectomy. The frequency of ectopic thymic tissue and the ratio to the surrounding adipose tissue were estimated. In our study, all patients, including patients >60 years, had thymic tissue in the surrounding adipose tissue removed during extended thymectomy. The probability of an ectopic thymus existing near the diaphragm, i.e., at the caudal end of the resection, was 13–19%, and the ratio of the area of the ectopic thymus to that of adipose tissue was <1% in almost all cases. In three patients with myasthenia gravis, an ectopic thymus was found in the adipose tissue around the diaphragm at a rate of >1%; there were no cases exceeding 10%. This value is extremely low compared with those of the other excision areas of extended thymectomy. Ectopic thymic tissues are far less likely to be present in adipose tissue on the diaphragm compared with that of other areas. This finding may help surgeons during the excision of adipose tissue around the thymus. [ABSTRACT FROM AUTHOR]

Background: Thymic tumors are unusual neoplasms, representing 0.2 to 1.5% of tumors in humans, but correspond to 20% of mediastinal tumors and 50% of those that occur in the anterior mediastinum. They tend to appear around the fourth and fifth decades of life without gender predilection. Up to 30% of patients are asymptomatic, therefore many are incidentally diagnosed. Radical thymectomy is the treatment of choice with high survival rates when detected in the early stages.Methods: This was a retrospective descriptive study, including 18 adult patients' diagnosis of thymic neoplasm, who were managed with surgical resection from 2011 to 2019. Information about demographics, clinical characteristics, imaging findings, surgical and medical management, plus histological findings was obtained and reported.Results: 18 patients with thymic tumors were included, of which specific histologic studies reveled thymomas, carcinomas, neuroendocrine tumors, thymolipoma and thymic cyst. Mean age was 52.7 years, with a predominance of male population. The main symptom was dyspnea, followed by cough and chest pain. Paraneoplastic syndromes such as myasthenia gravis, aplastic anemia and Cushing syndrome were reported. 89% of cases were treated by radical thymectomy alone, while only 2 cases required chemotherapy and radiotherapy. There were no surgical complications. Mean hospital stay length was 11. 9 days, with only 1 mortality during hospital admission. 5-year survival rate was 81%.Conclusions: The treatment of choice is radical thymectomy, which has been shown to positively impact patient mortality. Early detection is key to improve patient outcomes. [ABSTRACT FROM AUTHOR]

Background and purpose: Myasthenia gravis (MG) is an autoimmune disease with muscular weakness as the only symptom, and often with immunosuppressive treatment. All these aspects could have relevance for the risk of infections as well as their prophylactic and curative treatment.Methods: This is a review article, where Web of Science has been searched for relevant key words and key word combinations. Full papers were selected first by title and then by abstract.Results and conclusions: MG can be triggered and worsened by infections. No virus or other pathogen has been proven to have a specific link to MG. Treatment with immunosuppressive drugs and thymectomy implies a slightly increased risk for infections. Infections should be actively treated, but a few antibiotics are avoided due to potential interference with neuromuscular transmission. Hospitalization and intensive care may be necessary during infections because of MG deterioration and risk of insufficient respiration. Vaccinations are generally recommended in MG, but live microorganisms should be avoided if possible in immunosuppressed patients. [ABSTRACT FROM AUTHOR]

The therapeutic effect of thymectomy on myasthenia gravis is not completely understood. Several types of thymectomy varying in approach and extent have been performed. None of these disclosed a neat superiority over others. Patients desire thymectomy through small, painless, and cosmetically favorable operations. Videoassisted thoracoscopic surgery (VATS) thymectomy fits all these requests as well as that of the surgeon. Indeed, this approach allows for ample operative space, easy maneuverability, and extended thymectomy. No mortality, low morbidity, faster recovery, short hospital stay, and small economical costs are undoubtedly advantages of VATS over transsternal and transcervical thymectomy. In the near future, the introduction of robotic devices will lead to a new era in the surgery of the thymus. Herein we analyzed our comprehensive experience. [ABSTRACT FROM AUTHOR]

Background: This study aimed to compare the perioperative outcomes for patients who underwent transsternal or robot-assisted thymectomy and to determine the feasibility of robot-assisted thymectomy for the treatment of Masaoka stages 1 and 2 thymomas. Methods: The study evaluated the short-term outcomes for 74 patients undergoing surgery for Masaoka stages 1 and 2 thymomas without myasthenia gravis between January 2009 and December 2012. Of these 74 patients, 23 underwent thymoma resection using unilateral robot-assisted thoracoscopic surgery (RATS group), and 51 underwent transsternal thymectomy (TST group). Duration of surgery, amount of intraoperative blood loss, duration of chest drainage, duration of postoperative hospital stay, and postoperative complications were evaluated. Results: The intraoperative blood loss was significantly less in the RATS groups (61.3 ml) than in the TST group (466.1 ml) ( p < 0.01). The postoperative hospital stay was significantly shorter in the RATS group (3.7 vs 11.6 days; p < 0.01). No patients in the RATS group underwent conversion to open surgery. No severe surgical complications (e.g., bleeding caused by injury to the left brachiocephalic vein) and only one case of pulmonary atelectasis (appearing in a male patient 2 days after surgery) were detected in this series. Conclusion: Robot-assisted thoracoscopic thymectomy for early-stage thymomas is technically feasible, safe, and less invasive for the patient. [ABSTRACT FROM AUTHOR]

Abstract: The beneficial effects of thymectomy argue for a causal role of the thymus in myasthenia gravis (MG). The MG thymus contains acetylcholine receptor (AChR), which is expressed by myoid cells (whole AChR), and by medullary thymic epithelial cells (AChR subunits). The myoid cells are closely associated with antigen-presenting dendritic cells, helper T cells, and antibody-producing B cells in lymphoid follicles (“lymphofollicular hyperplasia”). Thus, all the cellular components required to initiate and maintain an autoimmune response to AChR are present in the MG thymus. It is unlikely that the cellular alterations in the thymus are secondary to an ongoing peripheral immune response, because they are absent in experimental autoimmune myasthenia gravis. [Copyright &y& Elsevier]

Abstract: The thymus is believed to play an important role in the pathogenesis of myasthenia gravis (MG). The 80% of MG patients with anti-acetylcholine receptor autoantibodies fall into three clinical subgroups: 1) thymoma; 2) early-onset MG (

Abstract: This review is dedicated to John Newsom-Davis, who was an exceptional colleague and friend, always exchanging ideas with respect and consideration. We shall not forget his involvement and passion in search for the truth on the role of thymectomy in the management of Myasthenia Gravis (MG). In this short review, we shall summarize what we learnt from DNA microarrays applied to MG thymus. We shall focus on three main comparisons of the thymic transcriptomes: 1) highly hyperplastic MG patients versus non-MG adults; 2) corticosteroid-treated versus untreated seropositive MG patients; and 3) seronegative versus seropositive MG patients. [Copyright &y& Elsevier]

The purpose of this report is to discuss the appropriate choice of procedures for video-assisted resection of thymoma according to factors such as the presence of myasthenia gravis or location of the tumor. We evaluated the short-term results of thoracoscopic surgery for 30 consecutive cases of noninvasive thymoma. Unilateral thoracoscopic partial (or subtotal) thymectomy (UTPT) was employed in patients with nonmyasthenic thymoma localized to the unilateral mediastinum, and extended (or total) thymectomy by an infrasternal mediastinal approach (ETIS) in myasthenic cases or those in which total thymectomy was considered inevitable. UTPT was performed on 11 nonmyasthenic patients, and ETIS on 19 (13 myasthenics and six nonmyasthenics). Three patients in the ETIS group underwent conversion to sternotomy because of pericardial dissemination, pleural adhesion, and vascular injury, respectively. The mean surgical duration was 163 min and 224 min and mean blood loss was 123 g versus 149 g for UTPT and ETIS, respectively. Post-thymomectomy myasthenia occurred in a patient after UTPT who made an excellent recovery to remission after the re-UTPT. There has not been any recurrence detected for 48 months of mean postoperative follow-up. Our trial regarding the choice of total or partial thymectomy in thoracoscopic surgery for thymomas yielded acceptable results that warrant further investigations into long-term survival and recurrence after longer-term observation of patients undergoing these procedures. [ABSTRACT FROM AUTHOR]

Background: Video-assisted thoracoscopic (VATS) thymectomy has been applied as a surgical option for autoimmune myasthenia gravis. Prior identification and fine division of the thymic veins are critical to the prevention of unexpected severe bleeding that may require conversion to open surgery. Until recently, such bleeding could be avoided only by meticulous dissection of thymic fat tissue away from the left brachiocephalic vein (LBV). With recent advances in computed tomography (CT), multidetector-row computed tomography (MDCT) can readily be obtained and provides three-dimensional (3D) images. This study explored its value for preoperative identification of the thymic veins draining into the LBV, and thus for prevention of injury to these veins during endoscopic thymectomy.Methods: Five patients with myasthenia gravis, thymoma, or both underwent enhanced MDCT preoperatively. The thymic veins draining into the LBV were visualized using both horizontal and sagittal/coronal CT images. Then 3D images were reconstructed to enable operators to simulate endoscopic views. During each VATS extended thymectomy, the numbers and branching patterns of the thymic veins were compared with the preoperative MDCT images.Results: The thymic veins draining into the LBV were clearly identified with MDCT in all five patients examined. Reconstructed 3D images clearly located their courses in the thymic/fat tissue and their entry routes into the LBV, thus simulating the actual intraoperative endoscopic views. All tributaries divided during surgery were identified preoperatively with MDCT.Conclusions: Location of thymic veins with MDCT can provide precise preoperative information about thymic venous anatomy. This easy and less invasive examination has the potential to make VATS thymectomy easier and safer. [ABSTRACT FROM AUTHOR]

The level of circulating thymic factor (FTS) tested by its action on spleen rosette-forming cells from adult thymectomized mice, has been shown to be stable in young animals. This stability suggests a regulatory mechanism. An approach of this regulation has been attempted by disrupting the FTS level either by neonatal thymus grafting in adult normal and thymectomized animals, or by injections of synthetic thymic factor into normal, thymectomized mice, grafted or ungrafted. In all cases, after an initial increase over the normal value, FTS levels returned close to the previous range, indicating the existence of some homeostatic mechanism of FTS secretion. [ABSTRACT FROM AUTHOR]

The effect of adult thymectomy on antibody production and on the development of contact sensitivity to picryl chloride in mice of different ages was studied. An age-dependent decline in the ability to develop contact sensitivity was found to be counteracted by thymectomy. In contrast, antibody production was regularly decreased by thymectomy in mice of all ages. A hypothesis is put forward in which the development of contact sensitivity may be regulated by long-lived thymus-dependent suppressor cells which do not affect antibody formation. [ABSTRACT FROM AUTHOR]