Presence Of Myasthenia Gravis Research Articles

Intratumoral metabolic heterogeneity by 18F-FDG PET/CT to predict prognosis for patients with thymic epithelial tumors.

The aim of the present study was to evaluate the impact of intratumoral metabolic heterogeneity and quantitative 18F-FDG PET/CT imaging parameters in predicting patient outcomes in thymic epithelial tumors (TETs). This retrospective study included 100 patients diagnosed with TETs who underwent pretreatment 18F-FDG PET/CT. The maximum and mean standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on PET/CT were measured. Heterogeneity index-1 (HI-1; standard deviation [SD] divided by SUVmean) and heterogeneity index-2 (HI-2; linear regression slopes of the MTV according with different SUV thresholds), were evaluated as heterogeneity indices. Associations between these parameters and patient survival outcomes were analyzed. The univariate analysis showed that Masaoka stage, TNM stage, WHO classification, SUVmax, SUVmean, TLG, and HI-1 were significant prognostic factors for progression-free survival (PFS), while MTV, HI-2, age, gender, presence of myasthenia gravis, and maximum tumor diameter were not. Subsequently, multivariate analyses showed that HI-1 (p < 0.001) and TNM stage (p = 0.002) were independent prognostic factors for PFS. For the overall survival analysis, TNM stage, WHO classification, SUVmax, and HI-1 were significant prognostic factors in the univariate analysis, while TNM stage remained an independent prognostic factor in multivariate analyses (p = 0.024). The Kaplan Meier survival analyses showed worse prognoses for patients with TNM stages III and IV and HI-1 ≥ 0.16 compared to those with stages I and II and HI-1 < 0.16 (log-rank p < 0.001). HI-1 and TNM stage were independent prognostic factors for progression-free survival in TETs. HI-1 generated from baseline 18F-FDG PET/CT might be promising to identify patients with poor prognosis.

Type B thymomas in patients with myasthenia gravis display a distinctive pattern of αβ TCR and IL-7 receptor α expression on CD4+CD8+ thymocytes

Thymoma is closely associated with myasthenia gravis (MG). However, due to the heterogeneity of thymoma and the intricate pathogenesis of MG, it remains unclear why some patients with thymoma develop MG and others do not. In this study, we conducted a comparative phenotype analysis of thymocytes in type B thymomas in patients with MG (MG (+) thymomas) and without MG (MG (−) thymomas) via fluorescence-activated cell sorting (FACS). Our results show that the developmental stages defined by the expression of CD3, CD4, and CD8 were largely maintained in both MG (+) and MG (−) thymomas, with CD4+CD8+ cells constituting the majority of thymocytes in type B thymoma, and no significant difference between this cell population was observed in MG (+) and MG (−) thymomas.We discovered that CD4+CD8+ thymocytes in MG (+) thymomas expressed low levels of αβ TCR and high levels of IL-7 receptor α (IL-7Rα), whereas in MG (−) thymomas, CD4+CD8+ thymocytes exhibited the opposite pattern of αβ TCR and IL-7Rα expression. These results suggest that the positive and negative selection processes of CD4+CD8+ thymocytes might differ between MG (+) thymomas and MG (−) thymomas. The expression of the Helios transcription factor is induced during negative selection and marks a group of T cells that have undergone negative selection and are likely to be deleted due to strong TCR binding with self-peptides/MHC ligands. We observed that the percentage of Helios-positive CD4SP T cells was greater in MG (−) than in MG (+) thymomas. Thus, the differentially regulated selection process of CD4+CD8+ thymocytes, which involves TCR and IL-7/IL-7Rα signaling, is associated with the presence of MG in type B thymomas.

Myasthenia gravis complicated by the development of COVID-19: an analysis of case series

Myasthenia gravis (MG) is an autoimmune disease characterized by increased dynamic muscleweakness. Patients with myasthenia gravis are united by the phenomenon of deterioration of the clinicalcondition after infection, refusal of treatment or taking certain medications, surgical intervention, exposureto heat and stress. In the context of the COVID‑19 (Coronavirus disease 2019) pandemic, the study ofpatients with myasthenia gravis and a new infectious disease may reveal new pathogenetic patterns andchange the therapeutic strategy.&#x0D; Objective — to identify clinical and paraclinical, therapeutic regularities in patients with MG and COVID‑19.&#x0D; Methods and subjects. From April 2021 to November 2021, the course of MG against the background ofCOVID‑19 in 11 patients was analyzed. The control group consisted of 7 patients with COVID‑19, butwithout MG. General clinical, neurological, instrumental, laboratory and statistical examination methods,scales Myasthenia Gravis Foundation of America (MGFA), The Quantitative Myasthenia Gravis Score (QMGS), Myasthenia Gravis Activities of Daily Living (MG‑ADL), The National Early Warning Score 2 (NEWS2) and questionnaires were used.&#x0D; Results. In the experimental and control groups, the level of SpO2 when breathing atmospheric air wascorrelated with the presence of bronchial asthma (BA) (r = –0.791), diabetes mellitus (DM) (r = –0.553),hypertension (r = –0.301). A positive correlation (r = 0.271) was found between the presence of MG and the level of SpO2 when breathing atmospheric air, which may be associated with the intake of pyridostigmine anda decrease in muscle mass in patients with MG. Presence of a relationship between the NEWS2 indicatorwith DM (r = 0.501), BA (r = 0.483), obesity (r = 0.376), hypertension (r = 0.352), multinodular goiter (r = 0.204), hydrothorax (r = 0.204) and MG (r = 0.120). In the myasthenia group, a relationship was established between the duration of treatment for COVID‑19 and body mass index (BMI) (r = 0.523), age (r = 0.504), pyridostigmine intake (r = –0.243) and weight (r = 0.228). NEWS2 in the experimental group was correlated with pyridostigmine intake (r = –0.386), weight (r = 0.355) and BMI (r = 0.256). Duration of treatment for COVID‑19 was associated with duration of MG (r = 0.570), obesity (r = 0.572), and BMI (r = 0.526). NEWS2 is related to the level of SpO2 when breathing atmospheric air (r = — 0.907), hemoglobin (r = –0.847) and vital capacity of the lungs (VC) (r = –0.699). Obesity (r = 0.787), anemia (r = 0.684) and BA were correlated with NEWS2. The finding of an inverse correlation between NEWS2 and pyridostigmine intake (r = –0.684) was promising. Soft palate paresis (r = –0.614), dysphagia (r = –0.614) and nasality (r = –0.545) were correlated with a decrease in VC. A correlation was found between VC and the NEWS2 (r = –0.699). The duration of COVID‑19 (r = –0.646) and patient age (r = –0.626) were correlated with VC.&#x0D; Conclusions. MG with the addition of COVID‑19 tends to worsen the course, progress of muscle weakness,development of respiratory failure and hypoxia. Aggravating factors are age, duration of MG, duration ofCOVID‑19, BMI, concomitant pathology (DM, hypertension, BA, obesity, anemia). Constitutional features(lower BMI and weight) may contribute to shortening the duration of treatment. Taking pyridostigmineallows to reduce not only the duration of treatment, but also the risk of worsening of the condition, whichmay be associated with the suppression of the inflammatory process when taking an anticholinesteraseagent.&#x0D;

Endoscopic Evaluation of Swallowing in Patient with Tetanus Followed by Myasthenia Gravis as Its Complication

Flexible Endoscopic Evaluation of Swallowing (FEES) provides direct visualization of the pharynx and larynx immediately before and after a swallow in a patient with dysphagia. Dysphagia is the difficulty in swallowing solid or liquid food. It is a symptom of an underlying disease like tetanus and myasthenia gravis. This case report showed the important role of FEES in patients with dysphagia due to tetanus followed by myasthenia gravis as its complication. A 58-year-old man had complaints of severe difficulty in swallowing followed by complaints of fever and whole body seizures, which supported the diagnosis of tetanus. In the course of the disease, symptoms and the results of supporting examinations indicated the presence of myasthenia gravis. Comprehensive management had done with colleagues in internal medicine, neurology and medical rehabilitation. That condition improved and the complaints disappeared after one month. It can be concluded that FEES played an important role in diagnosing dysphagia. It could identify the modification of food consistencies and therapeutic maneuvers to prevent an aspiration for a patient with dysphagia as the early symptom of tetanus which caused neurotransmitter damage that broke muscle nerve junctions. It is also one of the predisposing factors for autoimmune conditions in myasthenia gravis. Correct diagnosis and comprehensive management give a better improvement for the disease.

Thymomectomy versus complete thymectomy in early-stage non-myasthenic thymomas: a multicentric propensity score-matched study.

OBJECTIVESThymomectomy is gaining consensus over complete thymectomy in early-stage thymoma without myasthenia gravis. This is due both to the difficulty of establishing prospective and randomized controlled studies and to the lack of well-defined selection criteria. This bicentric, retrospective propensity score-matched study aims at comparing oncological outcomes, measured in terms of overall survival and thymoma-related survival, in patients undergoing either thymomectomy or complete thymectomy.METHODSWe retrospectively analysed medical records of patients with clinical early-stage (I and II) thymoma undergoing thymomectomy or complete thymectomy. Exclusion criteria were the presence of myasthenia gravis, clinical advanced tumours and thymic carcinoma. A propensity score-matching analysis was applied to reduce potential preoperative selection biases such as comorbidity (Charlson score), tumour maximal diameter and surgical approach (open versus minimal). All variables were dichotomized.RESULTSA total of 255 patients were enrolled from 2 different Hospitals, 126 underwent complete thymectomy and 129 a thymomectomy. Disease-free and thymoma-related survivals showed a 5-year rate of 87.7% and 96.0% and a 10-year rate of 82.2% and 91.9%, respectively. Propensity score-matching analysis selected a total of 176 patients equally divided between the 2 groups. No difference was found for both disease-free (P = 0.11) and thymoma-related (P = 0.37) survival in the 2 groups of resection. Multivariable Cox regression analysis showed that histology (P < 0.001), residual disease (P < 0.001) and adjuvant chemotherapy (P < 0.001) were the only predictors of shorter disease-free survival. Whereas there was no evidence to confirm that disease-free and thymoma-related survivals were influenced by resection extent.CONCLUSIONSThymomectomy is an adequate surgical resection for non-myasthenic thymoma, achieving disease-free and thymoma-related survivals comparable to those after complete thymectomy.

Pathological Features and Prognosis of Thymoma With or Without Myasthenia Gravis.

IntroductionTo evaluate the different pathological and clinical characters of thymoma with and without myasthenia gravis (MG) and to determine whether the presence of MG influences the prognosis in patients with thymoma.MethodsFour hundred and twenty-five consecutive patients operated was analyzed. A median sternotomy was used in 189 cases, and video-assisted thoracoscopic thymectomy was used in 236 cases. These patients with thymoma were subdivided into two groups: thymoma with myasthenia gravis MG (n = 220) and thymoma without MG (n = 205). All thymic epithelial tumors were classified according to the WHO histologic classification and the Masaoka clinical staging system. The result was evaluated according to the Myasthenia Gravis Foundation of America's criterion. The clinical features of the 2 test were compared between the two groups, and the survival analysis of Cox treatment effects was compared between the two groups.ResultsThere were no perioperative deaths. The proportions of type A and thymic carcinoma were 0% in the group with MG and 10.7% (22/205) and 11.2% (23/205), respectively, in the group without MG. Thymic hyperplasia around the thymoma was 29.1% (64/220) in patients with MG and only 6.3% (13/205) in patients without MG (χ2 = 23.63, P = 0.000). The overall survival curve showed that the 5- and 10-year survival rates in the group without MG were 89.2 and 77.4%, respectively, while those in the MG group were 91.1 and 80.5%.ConclusionsThe existence of MG has little influence on the prognosis of thymomas, but it is suitable for early diagnosis and treatment. Extended thymectomy should be performed on all patients with thymoma, whether they have MG or not.

Computed tomography radiomics for the prediction of thymic epithelial tumor histology, TNM stage and myasthenia gravis.

ObjectivesTo evaluate CT-derived radiomics for machine learning-based classification of thymic epithelial tumor (TET) stage (TNM classification), histology (WHO classification) and the presence of myasthenia gravis (MG).MethodsPatients with histologically confirmed TET in the years 2000–2018 were retrospectively included, excluding patients with incompatible imaging or other tumors. CT scans were reformatted uniformly, gray values were normalized and discretized. Tumors were segmented manually; 15 scans were re-segmented after 2 weeks by two readers. 1316 radiomic features were calculated (pyRadiomics). Features with low intra-/inter-reader agreement (ICC<0.75) were excluded. Repeated nested cross-validation was used for feature selection (Boruta algorithm), model training, and evaluation (out-of-fold predictions). Shapley additive explanation (SHAP) values were calculated to assess feature importance.Results105 patients undergoing surgery for TET were identified. After applying exclusion criteria, 62 patients (28 female; mean age, 57±14 years; range, 22–82 years) with 34 low-risk TET (LRT; WHO types A/AB/B1), 28 high-risk TET (HRT; WHO B2/B3/C) in early stage (49, TNM stage I-II) or advanced stage (13, TNM III-IV) were included. 14(23%) of the patients had MG. 334(25%) features were excluded after intra-/inter-reader analysis. Discriminatory performance of the random forest classifiers was good for histology(AUC, 87.6%; 95% confidence interval, 76.3–94.3) and TNM stage(AUC, 83.8%; 95%CI, 66.9–93.4) but poor for the prediction of MG (AUC, 63.9%; 95%CI, 44.8–79.5).ConclusionsCT-derived radiomic features may be a useful imaging biomarker for TET histology and TNM stage.

Difficult Decisions in Minimally Invasive Surgery of the Thymus.

Simple SummaryThe trend for thymoma surgery has been to increase utilization of minimally invasive options for resection; however, the primary objective should be to perform an oncological resection. One must consider the stage of tumor, presence of myasthenia gravis, presence of lymphadenopathy, and size of thymoma prior to deciding optimum surgical strategy.A minimally invasive resection of thymomas has been accepted as standard of care in the last decade for early stage thymomas. This is somewhat controversial in terms of higher-staged thymomas and myasthenia gravis patients due to the prognostic importance of complete resections and the indolent characteristics of the disease process. Despite concerted efforts to standardize minimally invasive approaches, there is still controversy as to the extent of excision, approach of surgery, and the platform utilized. In this article, we aim to provide our surgical perspective of thymic resection and a review of the existing literature.

Thymomas: Analysis of Histological Subtypes and Staging in Patients with Surgical Treatment in Two Reference Centers in Argentina

Background: Thymomas are a heterogeneous group of tumors which represent the most frequent tumor of the anterior mediastinum. Aims: To describe the clinical, histological, surgical and oncological characteristics of a cohort of patients with a diagnosis of thymoma surgically treated in two centers in Argentina and to evaluate the possibility of retrospectively implementing the 8th edition of TNM staging. Materials and Methods: 180 patients with thymoma surgically treated over a period of 41 years were studied. The following variables were analysed: age, sex, presence of myasthenia gravis at diagnosis, Masaoka staging (1994), TNM staging of thymus tumors, Histological classification (WHO 2015), neoadjuvant treatment with chemotherapy, post-operative radiation treatment and clinical evolution of myasthenia gravis defined according to the modified Osserman classification. Results: 96 men and 84 women were analysed. Median age 51 years (range 13-85). 85% of the patients analysed came from the public sphere. When analysing the institutional distribution by Masaoaka-Koga stage and TNM, a higher proportion of stages I was observed for both staging systems. Most myasthenic patients belonged to the WHO B2 histological classification (49%, p=0.04) and 15 patients received neoadjuvant treatment prior to surgery to improve the chances of resection, most of them classified as stages III of Masaoka (p=0.002) or IIIa of the TNM stage (p=0.001). 74 (46%) cases received post-operative RT when they presented Masaoka Koga stages II (p=0.000) and IIIa or more advanced TNM staging (p=0.000). 76% of the patients presented remission or stability of symptoms after surgical treatment and only 3/6 died due to myasthenic crisis in the immediate post-operative period. Conclusion: As reported in the literature, we have observed a higher frequency of B2 thymomas and their association with Myasthenia gravis. The histological criteria of the WHO 2015 classification, based on the ITMIG recommendations, favour precision in the definition of subtypes. The retrospective implementation of the 8th edition of TNM staging highlights the need to standardize protocols for pathological and surgical studies.

Comparison of the progression-free survival between robot-assisted thymectomy and video-assisted thymectomy for thymic epithelial tumors: a propensity score matching study.

BackgroundRobotic system was recently introduced to assist surgeons in performing thymectomy. However, whether robot-assisted thoracoscopic thymectomy (RATT) could replace video-assisted thoracoscopic thymectomy (VATT) and be considered as a superior treatment for thymic epithelial tumors is still controversial. The aim of this study was to evaluate the progression-free survival (PFS) and short-term clinical outcomes in patients undergoing RATT or VATT by comparing the matched two groups after performing propensity score analysis.MethodsWe retrospectively reviewed the clinical data of 295 patients diagnosed with thymic epithelial tumors. There were 60 patients in RATT group and 235 in VATT group. Propensity score matching was done between two groups with variables of age, gender, tumor size, organization histologic classification, original Masaoka stages, presence of myasthenia gravis (MG) and adjuvant therapy. Sixty patients from the RATT group and 60 from the VATT group were matched, fitting the model. The PFS and short-term clinical outcomes of matched groups were compared.ResultsAfter matching, the surgical time in RATT groups was significant shorter than that in VATT groups (P=0.042). Loco-regional recurrence and distal metastasis were detected in 4 patients with thymoma and 1 patient with thymic carcinoma in RATT group and in 25 patients with thymoma and 3 patients with thymic carcinoma in VATT group before matching. PFS were estimated in only thymoma cases. The PFS in RATT group (n=55) intended to be longer than that in VATT group (n=58) after matching (5-year PFS rate: 81.5% and 75.4%, respectively; log-rank P=0.095).ConclusionsRATT has the superiorities over VATT on short-term outcomes due to enabling surgeons to operate in a stable and comfortable environment. Meanwhile, RATT yielded a longer PFS compared with VATT, although the difference was not significant. Therefore, RATT could be considered as a standard approach for the treatment of thymic epithelial tumors.

The Terrible Triad of Checkpoint Inhibition: A Case Report of Myasthenia Gravis, Myocarditis, and Myositis Induced by Cemiplimab in a Patient with Metastatic Cutaneous Squamous Cell Carcinoma

Background We report a case of a patient with squamous cell carcinoma (SCC) who developed myasthenia gravis (MG), myositis, and myocarditis after receiving cemiplimab, an anti-PD-1 immune checkpoint inhibitor (ICI). Case Presentation. An 86-year-old man with metastatic periocular SCC presented with decreased vision in the left eye, severe fatigue, and lower back and bilateral hip pain 3 weeks after receiving cemiplimab. Within hours, he developed dysphonia, pharyngeal secretions, and dysphagia, necessitating intubation. Endomyocardial biopsy revealed active lymphocyte-mediated necrosis consistent with ICI-induced myocarditis. Anti-striated muscle and anti-acetylcholine receptor antibodies were elevated, consistent with myositis and myasthenia gravis. Despite plasma exchange therapy, steroids, and intravenous immunoglobulin, he died from cardiac arrest. Conclusions The presence of myasthenia gravis, myocarditis, or myositis should prompt evaluation for all three toxicities as they may represent an overlap syndrome. The severity of these immunotoxicities highlights the need for clinicians to suspect multiple simultaneous adverse effects of ICIs.

Predictive Features of Thymic Carcinoma and High-Risk Thymomas Using Random Forest Analysis.

To determine the predictive features of thymic carcinomas and high-risk thymomas using random forest algorithm. A total of 137 patients with pathologically confirmed high-risk thymomas and thymic carcinomas were enrolled in this study. Three clinical features and 20 computed tomography features were reviewed. The association between computed tomography features and pathological patterns was analyzed by univariate analysis and random forest. The predictive efficiency of the random forest algorithm was evaluated by receiver operating characteristic curve analysis. There were 92 thymic carcinomas and 45 high-risk thymomas in this study. In univariate analysis, patient age, presence of myasthenia gravis, lesion shape, enhancement pattern, presence of necrosis or cystic change, mediastinal invasion, vessel invasion, lymphadenopathy, pericardial effusion, and distant organ metastasis were found to be statistically different between high-risk thymomas and thymic carcinomas (all P < 0.01). Random forest suggested that tumor shape, lymphadenopathy, and the presence of pericardial effusion were the key features in tumor differentiation. The predictive accuracy for the test data and whole data was 94.73% and 96.35%, respectively. Further receiver operating characteristic curve analysis showed the area under the curve was 0.957 (95% confidence interval, 0.986-0.929). The random forest model in the present study has high efficiency in predictive diagnosis of thymic carcinomas and high-risk thymomas. Tumor shape, lymphadenopathy, and pericardial effusion are the key features for tumor differentiation. Thymic tumors with irregular shape, the presence of lymphadenopathy, and pericardial effusion are highly indicative of thymic carcinomas.

Analysis of the prevalence of myasthenia gravis in Ukraine depending on the place of residency and type of settlement

Aim: to study the prevalence of myasthenia gravis among adults in certain regions of Ukraine, taking into account the type of settlement and place of residence. The biostatistical, medical-statistical and epidemiological methods was used in the study. A study of the prevalence of myasthenia gravis in Ukraine was conducted on a sample of ten regions of Ukraine. 757 cases of myasthenia gravis were studied in selected territories, of which 465 (61.43 %) were among urban residents, 292 (38.57 %) were among rural residents. The average annual prevalence of myasthenia gravis was 5.16 (95 % CI —4.79—5.53) per 100,000 population. An analysis of the prevalence of myasthenia gravis in each region showed that this indicator among rural residents was statistically signifi cantly higher than the prevalence of myasthenia gravis among urban residents in Vinnytsia, Zaporizhzhia and Kirovohrad regions (p &lt; 0.05), and in Volyn, Ivano-Frankivsk, Mykolaiv and Chernivtsi regions — without statistically significant differences (p &gt; 0.05). The highest prevalence of myasthenia gravis in rural residents compared with urban residents was in the Vinnytsia region with an excess of 5.63 times (p &lt; 0.001). The city prevalences of myasthenia in the Dnipropetrovsk (+39.14 %; p = 0.001) and Poltava regions (+35.87 %; p = 0.048) signifi cantly exceeded the average city prevalence of myasthenia gravis in Ukraine. They were signifi cantly lower in Vinnytsia (–75.07 %; p &lt; 0.001), Volyn (–51.49 %; p &lt; 0.001), Ivano-Frankivsk (–42.58 %; p = 0.004) and Chernivtsi (–37.35 %; p = 0.046) regions. The chances of rural residents to have myasthenia gravis were signifi cantly higher compared to urban residents. In general, according to the data of mya sthenia gravis prevalence rate in the context of the place of residence, it was proved that living in rural areas is associated with the presence of myasthe nia gravis. Key words: myasthenia gravis, epidemiology, prevalence, incidence, urban residents, rural residents,

Surgical Treatment and Adjunctive Therapy in Thymic Epithelial Neoplasms: Evaluation of Outcomes in a Long-Term Follow-Up

SESSION TITLE: Cardiothoracic Surgery SESSION TYPE: Original Investigation Slide PRESENTED ON: Sunday, October 29, 2017 at 01:30 PM - 03:00 PM PURPOSE: Evaluate the characteristics of patients with thymic epithelial neoplasms and the effect of different therapeutic modalities available in a tertiary care hospital in Mexico. METHODS: Retrospective, observational study of patients diagnosed with thymic epithelial neoplasms who underwent surgical resection, chemotherapy and/or radiation therapy in a medical referral center. Demographic characteristics as well as information about the treatment received, potential complications and adverse effects were obtained and recorded through review and analysis of clinical records. A survival analysis was conducted taking into account the different treatment arms and clinical stages. RESULTS: In the period from January 1987 to May 2015, a total of 68 patients diagnosed with thymoma were identified in the hospital records. 41 (60%) patients were male and 27 (40%) women with and average age of 49.8 years (19-81). The main comorbidity was myasthenia gravis (66%). All underwent surgery and 23 (34%) received treatment plus chemotherapy and/or radiation. Most adverse effects were presented with surgery (68%). The average follow-up was 5 years. Survival at 5 and 10 years was 84% and 72% respectively. Free period of recurrence at 5 years was 87%. Significant higher 10-year survival prognostic factors were age, stage and type of resection. CONCLUSIONS: The study has a a representative sample of the features described in thymic epithelial neoplasms worldwide, plus several patients have had more than 10 years of monitoring. Survival obtained is similar to that reported in the literature. Surgery is the treatment of choice. The stage of the tumor, complete resection and advanced age are significant factors for overall survival, while the sex of the patient, the presence of myasthenia gravis and histological grade showed not be relevant. The role of radio and chemotherapy should be reevaluated. CLINICAL IMPLICATIONS: Our study is the first of its kind to be performed in our country and its results may be relevant when considering a certain type of treatment and performing the prognosis of each of the patients with thymoma in our institution and others centers of reference in spite of their relative infrequency, since their management represents a medical challenge. DISCLOSURE: The following authors have nothing to disclose: Rocio Carrera-Ceron, Julio Herrera-Zamora, Francina Bolaños Morales, Patricio Santillan-Doherty No Product/Research Disclosure Information

Post-operative delayed ambulation after thymectomy is associated withpre-operative six-minute walk distance

Objective: Delayed post-operative ambulation is a risk of post-operative complications and increases overall healthcare costs. We investigated pre-operative and intraoperative variables associated with delayed ambulation in patients who underwent thymectomy.Methods: A total of 57 consecutive patients undergoing thymectomy were included in this study. Pre-operative functional exercise capacity was evaluated by six-minute walk distance. Ambulation was considered to be delayed if the patient could not walk the ward on post-operative day 1. Binary logistic regression analysis was performed to clarify the factors associated with delayed ambulation.Results: Pre-operative six-minute walk distance was the only significant variable that was associated with delayed ambulation. The area under the receiver operating characteristic curve for predicting delayed ambulation was 0.684 (95% confidential interval: 0.546–0.823, p = 0.017), and the optimal discriminatory pre-operative six-minute walk distance value was 498 m. Post-operative hospital stay was significantly longer in patients with low six-minute walk distance (<498 m) than those with high six-minute walk distance (≥498 m). In contrast, the presence of myasthenia gravis or adjuvant chemoradiotherapy was not associated with delayed ambulation.Conclusions: Our results suggest that low pre-operative six-minute walk distance is associated with delayed post-operative ambulation and longer post-operative hospital stay in patients who underwent thymectomy.Implications for rehabilitationThe predictors for delayed ambulation after thymectomy are not fully investigated.The presence of myasthenia gravis was not associated with delayed ambulation.Low pre-operative six-minute walk distance was associated with delayed ambulation.

Editorial on "Postoperative survival for patients with thymoma complicating myasthenia gravis-preliminary retrospective results of the ChART database".

This article by Wang and coauthors analyzes the preliminary retrospective results of the ChART database on ‘Postoperative survival for patients with thymoma complicating myasthenia gravis’ (1). The Chinese Alliance for Research in Thymomas (ChART) registry recruited 2,306 patients with thymoma from 18 centers over the country in 20 (from 1992 to 2012) years with the intention to compare the postoperative survival between patients with thymoma only and those with both thymoma and myasthenia gravis (MG) so as to have a preliminary understanding of how MG affects the prognosis of patients with thymoma. Staging and histology are described as the most important prognostic factors for thymic tumors (2). The completeness of the resection is also certainly another important prognostic factor even in advanced stages (3). Tumor diameter is also a reliable prognostic factor (3). These findings has been shown again in this study with multivariate analyzes. Almost half a century ago, MG was believed to affect the prognosis adversely. This impact disappeared by advances in medical management of MG. At least, presence of MG is no longer considered as a negative prognostic factor, and even most of the recent reports have suggested significantly better survival (4-6). Conversely, other paraneoplastic syndromes are believed to affect the outcome of thymoma patients. In particular, acquired hypogammaglobulinemia, pure red cell aplasia cause significant morbidity (2). These syndromes include dermatopolymyositis, inflammatory bowel disease, pernicious anemia, rheumatoid arthritis, scleroderma and amyloidosis (2). This study demonstrates 5- and 10-year OS rates were both higher in MG group (93% vs. 88% and 83% vs. 81%, P=0.034, respectively). However, the survival rate was significantly higher in non-MG group when the Masaoka staging was 1 (P=0.000), and the result was opposite when the Masaoka staging was 3/4 (P=0.003). Only this analyze may show that the disease itself may not have an impact in survival of thymoma patients. But majority of difference may be coming from the histology and the size of the thymoma. There were significantly more proportion of patients with AB/B1/B2/B3 histology in the MG group while there were more patients with thymoma C in the non-MG group (P=0.000). Tumor size of MG group was also significantly smaller (6.4 vs. 7.9 cm, P=0.000) and the two groups were comparable in resectability. MG does have an impact on patients with thymoma. However, the onset of MG is a good reason for the timely diagnosis (smaller thymomas, early stage) which increases the possibility of overall R0 resection rate, which is an independent prognostic factor according to the multivariate analysis of this study. On the other hand, occurrence of Type C thymoma is an exceptional condition in MG patients. As shown recently, Type C has a tendency to develop more distant and lymph node metastases. All these might account for the positive influence of MG on the long term outcome of subjects with thymoma. I believe the secret of MG stays in the prevention of the patients from type C thymoma. The molecular studies in near future may clarify why MG protects the patients from developing thymic carcinoma.

Myasthenia gravis in patients with thymoma affects survival rate following extended thymectomy.

Thymomas are the most common adult tumors in the anterior mediastinal compartment, and a significant amount of thymomas are complicated by myasthenia gravis (MG). Extended thymectomy (ET) is the primary treatment method for thymomas and is used to completely resect possible ectopic thymus to avoid recurrence. Studies on the effect of MG in thymoma patients following ET are limited. The aim of the present study was to determine whether the presence of MG affects the prognosis of patients with thymoma. The present study consisted of 104 patients with thymoma that underwent ET; 61 men (58.7%) and 43 women (41.3%) (mean age, 54.6 years). In total, 38 patients had MG (36.5%). MG was most frequently observed in World Health Organization (WHO) classification type B2 thymoma compared with other types of thymoma. During the 5-year follow-up period, 11 patients succumbed to a recurrence of thymoma or respiratory failure due to MG. The overall 5-year survival rate in patients without MG or with MG was 89.1 and 76.0%, respectively. The overall survival (OS) rate in patients with Masaoka stages I + II and III + IV was 90.0 and 68.0%, respectively. The OS rate in patients with WHO type A + AB + B1 and type B2 + B3 was 96.9 and 76.8%, respectively. The patients with MG (P=0.026), Masaoka stages III + IV (P=0.008) and WHO type B2 + B3 (P=0.032) had a poorer prognosis compared with patients without these characteristics. Furthermore, multivariate analysis by Cox regression revealed that age [P=0.032; relative risk (RR)=1.097; 95% confidence interval (CI)=1.097-1.192] and MG (P=0.042; RR=0.167; 95% CI=0.037-0.940) significantly affected OS rate. In summary, ET is a reliable method for the treatment of thymoma. Long-term survival is expected for patients at early Masaoka stages, and for patients without MG. The prognosis of patients with thymomas with MG is poorer compared with patients without MG. The present findings provide useful information for the future management of patients with thymomas.

Role of Radiation Therapy in R1/R2 Resection and Prognostic Factors Associated With Survival in Thymoma

To evaluate the role of radiation therapy (RT) in post-operative Thymoma with R1/R2 resections and to assess the prognostic factors associated with survival. All patients with thymoma subtype A, AB, B1, B2 and B3 diagnosed between 1996 and 2010 were identified using pathology database. Hospital medical records were retrospectively reviewed for patient characteristics and treatment details. Patients who underwent simple biopsy or those with histological type C or thymic carcinoma were excluded. For the purpose of this study any histological grades reported using the older classifications were reviewed by the pathologists and reclassified as per the WHO system. Patients were grouped according to treatment types; surgery alone versus surgery and adjuvant RT. Overall survival (OS), disease free survival (DFS), freedom from recurrence (FFR) for R0 resections and time to progression (TTP) for R1/ R2 resections were analyzed and compared using log-rank test. The Cox regression model was used to analyze the prognostic factors. A total of 210 patients were identified. The median follow up was 6.8 years. There were 60 stage I (28.6%), 108 stage II (51.4%), 35 stage III (16.7%) and 7 stage IV (3.3%). Histological subtypes were; 23 type A (11%), 48 type AB (22.9%), 34 type B1 (16.2%), 65 type B2 (31%) and 40 type B3 (19%). Ninety-nine patients underwent surgery alone (47.1%) and 111 underwent surgery and adjuvant RT (52.9%). The 10 year OS was 82.2% for surgery compared to 90.1% for surgery and RT (p=0.763). The 10 year DFS was 79.7% and 80.8% respectively (p=0.797). Subgroup analysis of patients with R1/R2 resections showed the 10 year OS of 53.6% with surgery and 91.8% with surgery and RT (p=0.005). The 10 year DFS was 57.1% and 78.1% (0.088) respectively. No differences were found in FFR or TTP between two treatment groups. Both univariate and multivariate analysis showed age, presence of Myasthenia Gravis (MG) and Masaoka stage (I/II versus III/IV) as significant factors associated with OS. Masaoka stage alone was significant for DFS. Histological subtypes (A/AB/B1 versus B2/B3) had no prognostic impact on survivals; OS p=0.730, DFS p=0.072. Adjuvant RT improved OS and DFS in R1/R2 resections. Age, presence of MG and Masaoka stage were found as significant factors associated with overall survival in thymoma.

The relationship between myasthenia gravis and the different pathological type of thymoma patients' operation and prognosis

To evaluate the different pathological and clinical characteristics of thymomas with and without myasthenia gravis (MG) and to determine whether the presence of MG influences the prognosis in thymoma patients. The clinical data from 228 consecutive patients (median sternotomy were used in 153, video-assisted thoracoscopic themectomy were used in 75) operated on from January 1992 to December 2007 was analyzed retrospectively. These thymoma patients had been subdivided into two groups: thymoma with MG (n = 125) and thymoma without MG (n = 103). All thymic epithelial tumors were classified according to the WHO histologic classification and the Masaoka clinical staging system. The result was evaluated according to the Myasthenia Gravis Foundation of America's criterion. The clinical features of the 2 test was compared between the two groups by χ² test, and the survival were compared between the two groups by Cox analysis. There were no peri-operative deaths. 19 cases were inoperable (6 in the group with MG, 13 without MG (χ² = 4.52, P = 0.035)). The proportions of type A and thymic carcinoma were 0 in the group with MG, 10.5% (11/103) and 11.6% (12/103) respectively in the group without MG. According to the Masaoka's clinical staging, in the group MG, 24.8% (31/125) patients were stage III and IV; in the group without MG, 33.0% (34/103) patients were stage III and IV. There was a significant difference between hyperplastic paraneoplastic thymus coexisting in 28.8% (36/125) patients with MG and only 5.8% (6/103) in patients without MG (χ² = 20.91, P = 0.000) Microthymoma was identified in the paraneoplastic thymus of 3 patients with MG. There were 198 patients followed up, the rate was 86.8% (198/228). There was no recurrence in patients with type A and a few patients with type AB, B1, B2, B3 thymoma and thymic carcinoma recurred. The actuarial 5- and 10-year survival rates were 89.3% and 81.2% for patients with MG respectively, and 90.0% and 78.9% for patients without MG respectively. Within 5 years postoperatively, 6 of 9 patients with MG died of myasthenia crisis, while 6 out of 7 deaths in patients without MG were attributable to inoperable tumors (stage IV) and thymic carcinoma. The existence of myasthenia gravis has little influence on the prognosis of thymomas, but it is good for early diagnosis and treatment. Extended thymectomy should be performed to all patients with thymoma, no matter they have myasthenia gravis or not. The main cause of death is myasthenia crisis for thymoma patients with MG and stage IV and (or) thymic carcinoma for patients without MG.

Robotic thymectomy in patients with myasthenia gravis by vascular skeletonization.

Surgical resection of the thymus is indicated in the presence of myasthenia gravis (MG) and thymectomy is frequently used in the treatment of MG.