Incidence of thymoma in myasthenia gravis: a systematic review

[Myasthenia gravis-Gender aspects and family planning]

BACKGROUND

There is evidence that gender-specific differences can influence the diagnostics, treatment and long-term disease course of myasthenia gravis (MG). In women the diagnosis is often made during childbearing age.

OBJECTIVE

Gender-specific differences in MG and relevant aspects in routine clinical practice are presented. In addition, current studies on family planning, pregnancy and childbirth in MG are highlighted and treatment recommendations are derived.

MATERIAL AND METHODS

Narrative literature review.

RESULTS

In addition to sociodemographic data, gender-specific differences encompass clinical as well as paraclinical factors, such as disease severity and antibody status. With few exceptions pregnancy is possible with good maternal and neonatal outcome. During pregnancy and peripartum, children of MG patients should be closely monitored for early detection and treatment of potential syndromes caused by diaplacental transfer of maternal antibodies.

CONCLUSION

Gender-specific factors can influence the course of MG. Adequate medical counselling and multidisciplinary collaboration are essential for MG patients who wish to have children.

Treatment strategies and treatment-related adverse events in MG according to the age of onset

Introduction

Early-onset (EOMG) and late-onset (LOMG) are distinct groups of MG patients. It is unclear if treatment strategies and treatment-related adverse events may differ according to the age of MG onset.

Methods

This single-center retrospective study includes all MG patients followed at a tertiary center since 2007. We reviewed the electronic clinical records.

Results

In total, 212 patients were identified, 142 (67.0%) females, with a median disease duration of 10 years. The median age of symptom onset was 42.0 (26.0-64.5) years, with 130 (61.3%) EOMG cases and 82 (38.7%) LOMG. EOMG were more frequently female, had longer disease duration and often more generalized MG (p < 0.001). Comorbidities were significantly more frequent in LOMG (67.1%) compared to EOMG (53.1%) (p = 0.002). Steroid-related adverse effects motivating the switch to steroid-sparing agents (82.0%) were different between groups, with hypertension, hypercholesterolemia, diabetes mellitus and malignancies being more common in LOMG. At the same time, osteoporosis and dyspepsia were more frequent in EOMG (p < 0.001). The most common first-line choice was azathioprine (45.8%), and rituximab was used in 4 patients (1.9%).

Conclusion

Our study shows that treatment modalities are similar between EOMG and LOMG, while steroid-related adverse events appear to be distinct.

Epidemiology of paraneoplastic neurologic syndromes

Paraneoplastic neurologic syndromes (PNS), initially depicted as seemingly cryptic remote manifestations of malignancy, were first described clinically in the early 20th century, with pathophysiologic correlates becoming better elucidated in the latter half of the century. There remain many questions not only about the pathophysiology but also regarding the epidemiology of these conditions. The continuous discovery of novel autoantigens and related neurologic disease has broadened the association in classical PNS to include conditions such as paraneoplastic cerebellar degeneration. It has also brought into focus several other neurologic syndromes with a putative neoplastic association. These conditions are overall rare, making it difficult to capture large numbers of patients to study, and raising the question of whether incidence is increasing over time or improved identification is driving the increased numbers of cases. With the rise and increasing use of immunotherapy for cancer treatment, the incidence of these conditions is additionally expected to rise and may present with various clinical symptoms. As we enter an era of clinical trial intervention in these conditions, much work is needed to capture more granular data on population groups defined by socioeconomic characteristics such as age, ethnicity, economic resources, and gender to optimize care and clinical trial planning.

Myasthenia gravis treatment in the elderly presents with a significant iatrogenic risk: a multicentric retrospective study

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease treated with acetylcholinesterase inhibitors and immunosuppressant/immunomodulatory drugs. MG is frequently diagnosed in elderly patients, a fragile population in which treatment adverse effects (TAE) have not been evaluated until now.

METHODS

We retrospectively analysed the files of all MG patients with disease onset after age 70 years in four French University Hospitals, including clinical, electrophysiological, biological, and treatment data, with an emphasis on TAE. MG outcomes were assessed using the Myasthenia Gravis Foundation of America (MGFA) status scale.

RESULTS

We included 138 patients (59% of men) with a mean follow-up of 4.5 years (range 1-19). Mean age at diagnosis was 78 years (70-93). Anti-acetylcholine receptor antibodies were found in 87% of cases, electrophysiological abnormalities in 82%, and thymoma in 10%. MG outcome was good in a majority of cases, with 76% of treated patients presenting with alleviated symptoms at follow-up. TAE were observed in 41% of patients, including severe TAE in 14% of cases. Seven patients (5.1%) died, including four (2.9%) from MG-related respiratory failure, and three (2.2%) from MG treatment-related complications, i.e., sepsis in 2 cases and brain toxoplasmosis in 1 case. TAE were observed in 53% of patients treated with azathioprine, 23% of patients treated with corticosteroids, and 15% of patients treated with mycophenolate mofetil.

CONCLUSIONS

This retrospective study demonstrates MG in the elderly presents with a significant iatrogenic risk, including fatal immunosuppressant-related infections.

Robot versus video-assisted thoracoscopic thymectomy for large thymic epithelial tumors: a propensity-matched analysis

BACKGROUND

Both video-assisted thoracoscopic surgery (VATS) thymectomy and robot-assisted thoracoscopic surgery (RATS) thymectomy have been suggested as technically sound approaches for early-stage thymic epithelial tumors. However, the choice of VATS or RATS thymectomy for large and advanced thymic epithelial tumors remains controversial. In this study, the perioperative outcomes of VATS and RATS thymectomy were compared in patients with large thymic epithelial tumors (size ≥5.0 cm).

METHODS

A total of 113 patients with large thymic epithelial tumors who underwent minimally invasive surgery were included. Sixty-three patients underwent RATS, and 50 patients underwent VATS. Patient characteristics and perioperative variables were compared.

RESULTS

Compared with the VATS group, the RATS group experienced a shorter operation time (median: 110 min vs.130 min; P < 0.001) and less blood loss (30.00 ml vs. 100.00 ml, P < 0.001). No patients in the RATS group needed conversion to open surgery, but in the VATS series, five patients required conversion to open procedures (0% vs. 14.29%, P = 0.054). The rate of concomitant resection in the RATS group was similar to that in the VATS group (11.43% vs. 5.71%; P = 0.673). There was no significant difference between the two groups in the duration of chest tube (P = 0.587), postoperative complications (P = 1.000), and the duration of postoperative hospital stay (P = 0.141).

CONCLUSION

For large thymic epithelial tumors, RATS thymectomy can be performed safely and effectively in a radical fashion. Due to the advanced optics and precise instrument control, concomitant resections can be easily achieved in larger thymic epithelial tumors using the robotic approach.

Clinicodemographic characteristics and prognostic role of myasthenia gravis in thymoma: Experience from a Saudi population

OBJECTIVES

The objectives of the study were to determine the clinicodemographic characteristics and the prognostic role of myasthenia gravis (MG) in thymoma.

METHODS

The records of patients who underwent surgical resection of thymoma at King Faisal Specialist Hospital and Research Center in the past 23 years were reviewed. Seventy thymoma patients were finally included and were then categorized based on MG status into the MG group (39 patients) and the non-MG group (31 patients). Collected data included patients' demographic characteristics, tumor characteristics, and postoperative clinical outcomes. All analyses were conducted using SPSS. The comparison between both groups was tested using the Student t-test and Chi-square test for continuous and categorical variables, respectively. A P = 0.05 or less indicated statistical significance.

RESULTS

Patients' age ranged from 11 to 76 years, and female predominance was observed (55.7%). Compared to the non-MG group, no difference in patients' gender was observed (P = 0.058); however, MG patients had a younger age (39.30 vs. 48.77, P = 0.0095). No difference was noted between both groups based on the World Health Organization classification (P = 0.398), but MG patients tended to present with less-advanced tumors based on the TNM classification (P = 0.039) and lower stage based on the MASAOKA staging system (P = 0.017). No significant change in tumor size (P = 0.077), resectability (P = 0.507), and adjuvant therapy (P = 0.075) were observed. MG was not significantly associated with postoperative complications, morbidity, or mortality. However, it exhibited a prognostic protective role in terms of lower recurrence (2.56% vs. 35.48%, P = 0.0001) and longer survival duration (18.62 vs. 10.21 years, P < 0.001) as compared to non-MG patients.

CONCLUSIONS

MG occurrence in thymoma patients is more likely to occur at a younger age, higher TNM classification, and advanced MASAOKA stage. Although no significant association was noted between MG and complications and mortality, MG exhibited a protective role in thymoma by providing a lower recurrence rate and longer survival duration.

Thymoma: An Overview

Thymomas are considered one of the most prevalent types of mediastinal epithelial tumors, which frequently develop in the anterior mediastinum. Due to their rarity, these tumors' nomenclature, classification, and staging are likely to be the subject of debate and argument for most expert pathologists. Furthermore, the significance of thymoma histologic classifications have been debated over the past twenty years. While certain advocates argue that staging at the time of diagnosis is more significant, others believe that histologic subtyping has a significant impact on how patients behave clinically. In this review, we will focus on some of the challenges that diagnostic surgical pathologists may experience while evaluating the histopathology of thymomas and staging these tumors. We will additionally glance over the clinical characteristics of these distinct tumors and the current management strategy.

Granulomatous myopathy: Sarcoidosis and beyond

Non-necrotizing granulomatous inflammation is a rare but easily recognized histopathological finding in skeletal muscle biopsy. A limited number of diseases are known to be associated with non-necrotizing granulomatous myopathy. Once identified, a careful evaluation for evidence of extramuscular granulomatosis and other signs suggestive of sarcoidosis is warranted as about half of the patients have sarcoid myopathy. In addition, the presence of granulomatous myopathy should trigger a search for clinical and pathological clues of inclusion body myositis (IBM), which accounts for most of the remaining patients and can coexist with sarcoidosis. Recognizing the features of IBM in patients with granulomatous myopathy can potentially spare the patients from unnecessary exposure to immunosuppressive therapies. In patients whose granulomatous myopathy remain unexplained, further investigations should aim at identifying myasthenia gravis and other autoimmune disorders, especially those known to cause granulomatous inflammation in other organs. Laboratory investigations should include acetylcholine receptor, antimitochondrial, antineutrophil cytoplasmic, thyroglobulin, and thyroid peroxidase autoantibodies. In the appropriate clinical context, exposure to immune checkpoint inhibitors and chronic graft-vs-host disease can be causes of granulomatous myopathy. In cases of unexplained granulomatous myopathy, natural killer/T-cell lymphoma should be considered and careful histopathological examination for atypical cells and appropriate immunostaining is crucial. Identifying the etiology of granulomatous myopathy in each patient can guide appropriate treatment.

Immunological and Structural Characterization of Titin Main Immunogenic Region; I110 Domain Is the Target of Titin Antibodies in Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies targeting the neuromuscular junction (NJ) of skeletal muscles. The major MG autoantigen is nicotinic acetylcholine receptor. Other autoantigens at the NJ include MuSK, LRP4 and agrin. Autoantibodies to the intra-sarcomeric striated muscle-specific gigantic protein titin, although not directed to the NJ, are invaluable biomarkers for thymoma and MG disease severity. Thymus and thymoma are critical in MG mechanisms and management. Titin autoantibodies bind to a 30 KDa titin segment, the main immunogenic region (MIR), consisting of an Ig-FnIII-FnIII 3-domain tandem, termed I109-I111. In this work, we further resolved the localization of titin epitope(s) to facilitate the development of more specific anti-titin diagnostics. For this, we expressed protein samples corresponding to 8 MIR and non-MIR titin fragments and tested 77 anti-titin sera for antibody binding using ELISA, competition experiments and Western blots. All anti-MIR antibodies were bound exclusively to the central MIR domain, I110, and to its containing titin segments. Most antibodies were bound also to SDS-denatured I110 on Western blots, suggesting that their epitope(s) are non-conformational. No significant difference was observed between thymoma and non-thymoma patients or between early- and late-onset MG. In addition, atomic 3D-structures of the MIR and its subcomponents were elucidated using X-ray crystallography. These immunological and structural data will allow further studies into the atomic determinants underlying titin-based autoimmunity, improved diagnostics and how to eventually treat titin autoimmunity associated co-morbidities.

Myasthenia gravis-specific aberrant neuromuscular gene expression by medullary thymic epithelial cells in thymoma

Myasthenia gravis (MG) is a neurological disease caused by autoantibodies against neuromuscular-associated proteins. While MG frequently develops in thymoma patients, the etiologic factors for MG are not well understood. Here, by constructing a comprehensive atlas of thymoma using bulk and single-cell RNA-sequencing, we identify ectopic expression of neuromuscular molecules in MG-type thymoma. These molecules are found within a distinct subpopulation of medullary thymic epithelial cells (mTECs), which we name neuromuscular mTECs (nmTECs). MG-thymoma also exhibits microenvironments dedicated to autoantibody production, including ectopic germinal center formation, T follicular helper cell accumulation, and type 2 conventional dendritic cell migration. Cell–cell interaction analysis also predicts the interaction between nmTECs and T/B cells via CXCL12-CXCR4. The enrichment of nmTECs presenting neuromuscular molecules within MG-thymoma is further confirmed immunohistochemically and by cellular composition estimation from the MG-thymoma transcriptome. Altogether, this study suggests that nmTECs have a significant function in MG pathogenesis via ectopic expression of neuromuscular molecules.

Unilateral video-assisted thoracoscopic thymoma resection – Indications, early and mid-term results

Introduction. Thymoma is the most common tumour of the anterior mediastinum. Video-Assisted Thoracic Surgery technique of thymoma resection is spreading world-wide, but the thoracoscopic method is still contentious in many ways. Authors evaluate the early and mid-term results of a 17 years period of VATS unilateral approach at 2 Hungarian thoracic surgical centers. Method. Depending on the anatomical situation of the thymoma, we performed thymectomy, or partial thymectomy (thymomectomy) for the Masaoka–Koga I–II–III stage thymoma from the right or left side through 2 or 3 intercostal ports. We managed the operations with ultrasonic dissector and electrocauter. By using international standards we evaluated perioperative morbidity, mid-term oncological results and clinical symptoms of myasthenia. Results. 23 of the 54 patients were man, 31 were woman, the average age was 58 (26–79) years, 23 of them had myasthenia. The conversion rate was 11,5% (7/61). The average operation time was 84 (39–150) minutes. The average hospitalisation time was 5.5 (3–19) days. The average size of the thymomas was 46 (18–90) mm. The histology resulted thymoma type A in 2 cases, AB in 19 cases, B1/2/3 in 11/11/1 cases, mixed B in 10 cases. The examination of the resection line was R0/1/2 in 42/11/1 cases. The Masaoka–Koga stages were: I (17), IIA (28), IIB (2), III (7). There was 25 thymomectomies, and 29 thymectomies. In seven cases there were extension of the operation to the pericardium (2), to the lung (2), to the phrenic nerve (6), and to innominate vein (1). The in-hospital mortality over 30 day was in 1 case (1.85%). The morbidity was 11/54 (20.4%). The average follow-up time was 62.56 (5–198) months. In the group with myasthenia the effectivity of the operation was 18/21 (85.7%), including complete remission of 5/21 (23.8%). Post-thymectomy myasthenia gravis developed in 2/31 cases (6.5%). The average 5 years survival was 100%, tumour-free 5 years survival was 96%. Conclusions. The higher proportion of the thymomectomy in the early results, higher conversion rate and lower R0 proportion might be in connection with the attitude of the surgeons, with the learning curve and with the limitations of the unilateral method. After a longer follow-up time late results may become more real and comparable. Instead of unilateral VATS technique we have changed to the subxyphoideal approach of VATS because of its better visualisation.

Preferential X Chromosome Inactivation as a Mechanism to Explain Female Preponderance in Myasthenia Gravis

Myasthenia gravis (MG) is a neuromuscular autoimmune disease characterized by prevalence in young women (3:1). Several mechanisms proposed as explanations for gender bias, including skewed X chromosome inactivation (XCI) and dosage or sex hormones, are often involved in the development of autoimmunity. The skewed XCI pattern can lead to an unbalanced expression of some X-linked genes, as observed in several autoimmune disorders characterized by female predominance. No data are yet available regarding XCI and MG. We hypothesize that the preferential XCI pattern may contribute to the female bias observed in the onset of MG, especially among younger women. XCI analysis was performed on blood samples of 284 women between the ages of 20 and 82. XCI was tested using the Human Androgen Receptor Assay (HUMARA). XCI patterns were classified as random (XCI < 75%) and preferential (XCI ≥ 75%). In 121 informative patients, the frequency of skewed XCI patterns was 47%, significantly higher than in healthy controls (17%; p ≤ 0.00001). Interestingly, the phenomenon was observed mainly in younger patients (<45 years; p ≤ 0.00001). Furthermore, considering the XCI pattern and the other clinical characteristics of patients, no significant differences were found. In conclusion, we observed preferential XCI in MG female patients, suggesting its potential role in the aetiology of MG, as observed in other autoimmune diseases in women.

Thymic Lesions in Myasthenia Gravis: A Clinicopathological Study from India

Background and Objectives: Thymic pathology is common in Myasthenia Gravis(MG) and plays a crucial role in its pathogenesis and clinical outcome. This study aims to discuss the clinicohistopathological spectrum of thymic lesions in MG. Methods: In this retrospective study, MG patients who underwent thymectomy from 2011 to 2020 were included. Clinical, radiological, serological, and histopathological details are described. Results: Of 83 patients(F = 45; M = 38), 7(8%) had ocular myasthenia, and the remaining 76(92%) had the generalized form. At onset, the median age was 36 years(M = 44; F = 31). AChR antibody was positive in 71/79 patients. RNST showed decrement response in 68/78 patients. The histopathological study demonstrated thymoma in 44(53%), thymic hyperplasias [32(38%)], involuted thymus [5(6%)], thymic cyst (1) and thymic lipoma (1). WHO grading of thymoma: B2- 48%, AB-18%, B-18%, B3-14%, A-2.3% . In these, capsular infiltration was noted in 11/44, 9 had focal and 2 had diffuse infiltration. Active germinal centers were present in 20/32 patients with thymic hyperplasia and 4/44 with thymoma. Thymomas were predominant in males and thymic hyperplasia in females. The age of onset and antibody positivity rate was higher in thymoma patients. Conclusion: In our cohort, there is a female preponderance. Thymoma was the commonest pathology followed by hyperplasia. We observed earlier onset of myasthenia in females. AChR antibody positivity rate was more frequent in thymomas. This study indicates that clinico-radiological evaluation adequately supported by serology and histopathology can effectively recognize the type of thymic pathology that can guide these patients’ treatment planning, management, prognosis and follow-up.

Neonatal Fc Receptor-Targeted Therapies in Neurology

Autoantibodies are increasingly recognized for their pathogenic potential in a growing number of neurological diseases. While myasthenia gravis represents the prototypic antibody (Ab)-mediated neurological disease, many more disorders characterized by Abs targeting neuronal or glial antigens have been identified over the past two decades. Depletion of humoral immune components including immunoglobulin G (IgG) through plasma exchange or immunoadsorption is a successful therapeutic strategy in most of these disease conditions. The neonatal Fc receptor (FcRn), primarily expressed by endothelial and myeloid cells, facilitates IgG recycling and extends the half-life of IgG molecules. FcRn blockade prevents binding of endogenous IgG to FcRn, which forces these antibodies into lysosomal degradation, leading to IgG depletion. Enhancing the degradation of endogenous IgG by FcRn-targeted therapies proved to be a powerful therapeutic approach in patients with generalized MG and is currently being tested in clinical trials for several other neurological diseases including autoimmune encephalopathies, neuromyelitis optica spectrum disorders, and inflammatory neuropathies. This review illustrates mechanisms of FcRn-targeted therapies and appraises their potential to treat neurological diseases.

Does robotic-assisted thymectomy have advantages over video-assisted thymectomy in short-term outcomes? A systematic view and meta-analysis

OBJECTIVES

A thymic epithelial tumour is the most common primary tumour in the anterior mediastinum of adults. A few retrospective studies compared the short-term outcomes between robotic-assisted thymectomy (RAT) and video-assisted thymectomy (VAT). So, it is necessary to conduct a meta-analysis to further compare these 2 surgical techniques.

METHODS

EMBASE, Medline and Web of Science were used. Thesaurus terms and medical subject headings were used in Medline and EMBASE, respectively. The Newcastle-Ottawa scale was used for grading because the included studies were all case-control studies.

RESULTS

Nine studies were included in the meta-analysis with a total of 723 patients, including 315 patients in the RAT group and 408 patients in the VAT group. The meta-analysis [odds ratio (OR) 0.24, 95% confidence interval (CI) 0.06-0.94; P = 0.041], indicating that RAT yielded a significantly lower rate of conversion compared with VAT. Duration of drainage with RAT was significantly less than that with VAT (weighted mean difference = -1.10; 95% CI -1.98 to -0.22; P = 0.014). The pooled analysis (weighted mean difference = -103.6; 95% CI -199.21 to -7.98; P = 0.034) suggested that patients in the RAT group had less drainage than those in the VAT group. The recurrence rates in both groups were comparable (OR 0.19, 95% CI 0.03-1.20; P = 0.078).

CONCLUSIONS

RAT has advantages over VAT in terms of short-term outcomes such as shorter duration of drainage, less total drainage and a lower rate of conversion. The recurrence rate was comparable between the 2 techniques. Therefore, RAT could be considered as an alternative treatment for diseases of the thymus.

Impact of the Surgical Approach to Thymectomy Upon Complete Stable Remission Rates in Myasthenia Gravis: A Meta-analysis

OBJECTIVES

To determine whether the available operative techniques for thymectomy in myasthenia gravis (MG) confer variable chances for achieving complete stable remission (CSR), we performed a meta-analysis of comparative studies of surgical approaches to thymectomy.

METHODS

Meta-analysis was done of all studies providing comparative data on thymectomy approaches, with CSR reported and minimum 3-year mean follow-up.

RESULTS

Twelve cohort studies and 1 randomized clinical trial, containing 1,598 patients, met entry criteria. At 3 years, CSR from MG was similar after video-assisted thoracoscopic (VATS) extended vs both basic (relative risk [RR] 1.00, p = 1.00, 95% confidence interval [CI] 0.39-2.58) and extended (RR 0.96, p = 0.74, 95% CI 0.72-1.27) transsternal approaches. CSR at 3 years was also similar after extended transsternal vs combined transcervical-subxiphoid (RR 1.08, p = 0.62, 95% CI 0.8-1.44) approaches. VATS extended approaches remained statistically equivalent to extended transsternal approaches through 9 years of follow-up (RR 1.51, p = 0.05, 95% CI 0.99-2.30). The only significant difference in CSR rate between a traditional open and a minimally invasive approach was seen at 10 years when the now-abandoned basic (non-sternum-lifting) transcervical approach was compared to the extended transsternal approach (RR 0.4, p = 0.01, 95% CI 0.2-0.8).

CONCLUSIONS

A significant difference in the rate of CSR among various surgical approaches for thymectomy in MG was identified only at long-term follow-up and only between what might be considered the most aggressive approach (extended transsternal thymectomy) and the least aggressive approach (basic transcervical thymectomy). Extended minimally invasive approaches appear to have CSR rates equivalent to those of extended transsternal approaches and are therefore appropriate in the hands of experienced surgeons.

Recurrent neutropenia and chronic diarrhea following thymectomy: the good, the bad, and the ugly

Good syndrome (GS) is a rare paraneoplastic syndrome seen before or after diagnosis of thymoma, and its treatment, and is characterized by hypogammaglobulinemia. Rarely, pure white cell aplasia (PWCA) can also be seen which can present as recurrent neutropenia. We describe a 64-year-old man with recurrent sinus infections and previous thymectomy for stage 1 type B2 thymoma presenting with chronic diarrhea and recurrent neutropenia necessitating serial hospitalizations despite repeated antimicrobial treatment. Immunoglobulin levels, including IgM, IgA, IgD, and IgE were undetectable. Flow cytometry also showed absent B cells. Patient was initiated on immunoglobulin replacement therapy with consequent significant clinical improvement. Despite thymectomy, patients can develop thymoma-associated paraneoplastic syndromes, including GS.

Myasthenia gravis presenting as bilateral pseudointernuclear ophthalmoplegia in a patient with an incidental prolactinoma

Myasthenia gravis (MG) is a rare and potentially dangerous autoimmune condition, which affects the acetylcholine receptors at the neuromuscular junction of skeletal muscle. MG's diverse symptomatology may readily masquerade as other neurological conditions, posing a diagnostic challenge to clinicians. We describe a 24-year old man who presented to the emergency department with a new onset internuclear ophthalmoplegia. After a series of investigations, we eventually arrived at a diagnosis of MG with pseudointernuclear ophthalmoplegia with an incidentally detected prolactinoma. We explore the literature regarding the pathophysiology of pseudointernuclear ophthalmoplegia, the link between prolactin and autoimmunity and the association between prolactinoma and MG.

Challenges in diagnosing coexisting ocular myasthenia gravis and thyroid eye disease

Ocular myasthenia gravis (OMG) and thyroid eye disease are two autoimmune conditions that have several overlapping clinical features, and these coexist with a small but not insignificant frequency. Segregating these diagnoses is typically straightforward, but, when the two diseases co-occur in the same individual, making a diagnosis of OMG can be very challenging. In this review we address what is known about the coexistence of OMG and thyroid eye disease and we highlight the clinical features that are suggestive of overlapping conditions. We also describe the major testing approaches used in the diagnosis of these two entities, with special emphasis on the potential shortcomings of individual tests in patients with overlapping disease. In patients with thyroid eye disease, securing a diagnosis of OMG may not be possible on the basis of a single positive test. A multimodal approach using clinical, serologic, imaging, and electrodiagnostic data, is typically required.

Acute Myasthenia Crisis: A Critical Emergency Department Differential

Myasthenia gravis (MG) is the most common autoimmune disorder of the neuromuscular junction (NMJ). It is caused by autoantibodies blocking acetylcholine receptors (AChRs) or structural receptors of the NMJ: agrin, LRP4, and MuSK. These antibodies can block, change, or destroy AChRs or structural proteins of the NMJ, preventing the binding of ACh and therefore, muscle contractions. This molecular dysfunction can manifest as any of the following symptoms: ptosis, diplopia, bulbar dysfunction, or impaired vision in bright light. Symptoms fluctuate in severity throughout the day and with prolonged use of respective muscles. Typical treatment for mild cases is acetylcholinesterase inhibition combined with an immunosuppressor. Myasthenia crisis results from the exacerbation of the aforementioned symptoms and requires intubation for respiratory support. Intensive care along with intensified immunosuppressive treatments and constant monitoring are recommended. We present the case of a 76-year-old man arriving to the emergency department (ED) with symptoms of fatigue and dysphagia, diagnosed as acute myasthenia crisis. Here, we highlight the symptoms of MG, acute myasthenia crisis, and the critical measures that need to be taken.

Aplastic Anemia Secondary to Thymectomy in a Patient With Myasthenia Gravis

It is a well-described phenomenon in the literature that a thymoma can lead to aplastic anemia, and that a thymectomy can be curative for to aplastic anemia. However, the opposite is extremely rare. We present an unusual case of a 60-year-old woman with myasthenia gravis, who was diagnosed with an incidental thymoma found on computerized tomography. Resection of the thymoma treated her myasthenia gravis but led to an aplastic anemia resistant to granulocyte colony-stimulating factor, cyclosporin, and horse antithymocyte globulin treatment. The patient received an allogenic stem cell transplant but unfortunately passed away because of complications.

Robotic thymectomy for advanced thymic epithelial tumor: indications and technical aspects

Robotic thymectomy is widely accepted as a valuable treatment option for surgical resection of thymic epithelial tumor as minimally invasive surgery has shown better early clinical outcomes than open surgery. Technical advances in robotic surgery have expanded the indications for robotic thymectomy, and the technique can be used to perform complete resection of advanced thymic epithelial tumor requiring concomitant resection of adjacent structures. To ensure complete resection, a multi-disciplinary approach, with thorough preoperative evaluation, must be adopted to determine whether a patient shows surgical indications for advanced thymic epithelial tumor. The early clinical outcomes after robotic thymectomy to treat advanced thymic epithelial tumor are promising; however, the long-term oncologic outcomes should be evaluated in the further studies.

Technique for Myasthenia Gravis: Subxiphoid Approach

Kido and colleagues in 1999 used for the first time the subxiphoid approach. Recently, video-assisted thoracoscopic surgery (VATS) thymectomy has been improved for the advancement of surgical materials and new instruments. The most important aspect regarding the subxiphoid approach is the possibility to avoid the intercostal nerve damage with the consequence of a decreased use of postoperative analgesics, quite short surgical duration, fast discharge from hospital and a guarantee of successful cosmetics results.

Incidence and clinical variable inter-relationships of thymic epithelial tumors in northwest China

Background

Thymic epithelial tumors (TETs) are the most common primary thymus tumors, but neither the possible ethnical/regional differences in the incidence of TETs nor the inter-relationships among the clinical variables has been revealed in northwest China.

Methods

A retrospective chart review was performed among pathologically confirmed TET patients from January 2004 to December 2015 in a tertiary general hospital of northwest China and the incidence, clinical features and the inter-relationships among clinical variables were analyzed.

Results

A total of 603 pathologically confirmed TETs patients (age range, 5-78 years; 308 males) were enrolled and the most common lesion location was anterior mediastinum (98.5%), among them, 192 (31.8%) had myasthenia gravis (MG). Twenty-six (5.7%), 112 (24.6%), 83 (18.2%), 137 (30.1%), 74 (16.3%), and 23 (5.1%) patients fell into the World Health Organization (WHO) type A, AB, B1, B2, B3 and thymic carcinoma (TC), respectively. The incidence of TETs was slightly higher in the female population and the age group of 40-60 years old. In addition, MG predominantly coexisted with WHO types A-B3 TETs and the TETs with MG were smaller than those without MG. The correct diagnosis rates were 42.3% (77 out of 182), 61.1% (127 out of 208), 89.3% (250 out of 280) and 75.0% (3 out of 4) for chest X-ray, non-contrast computed tomography (CT), contrast CT scan and magnetic resonance imaging (MRI), respectively.

Conclusions

Distinct gender and age differences exist in the incidence of TETs and the A-B3 TETs are closely related with MG. Contrast CT scan plays more important role in diagnosing TETs.

Comparative study of computed tomography of normal and lymphoid follicular hyperplasia thymus in myasthenia gravis patients

The aim of the present study was to evaluate the thymuses of non-thymomatous myasthenia gravis (MG) patients by computed tomography (CT) for differentiating lymphoid follicular hyperplasia (LFH) thymus from normal/involuted thymus in order to assist surgeons in determining whether a non-thymomatous MG patient requires an operation. In the present retrospective review over 10 years, 80 patients who received CT scan and thymectomy at the Affiliated General Hospital of Tianjin Medial University (Tianjin, China) were included. According to the pathological records, 54 of the cases initially detected on CT were confirmed as LFH thymus. Thymic measurements, including anteroposterior and transverse dimensions, width (the longest axis of the lobe on a transverse scan) and thickness (the largest dimension perpendicular to the long axis of the lobe) and CT attenuation of the thymus region, adipose tissue and chest wall musculature in each CT slice were included to assess differences between the LFH group and the normal/involuted thymus group. Although a negative association between patient age and the CT attenuation of the thymus region was identified (r=-0.779, P<0.05, Pearson's correlation test), the LFH thymus group featured nodular changes on CT, while no such changes were observed in the normal/involuted thymus group. The mean age of disease onset in the LFH thymus group was significantly lower than that in the normal thymus group (40.2±17.3 vs. 59.2±9.3 years). Furthermore, significant differences in CT attenuation were identified between the LFH group and the normal/involuted thymus group [-41.21±54.42 vs. -108.23±8.72 Hounsfield units (HU) on unenhanced CT; -25.57±58.65 vs.-117.40±6.22 HU on contrast-enhanced CT]. In the LFH group, the difference in mean CT attenuation between the thymus region and adipose tissue was significant, while no significant difference was observed in the normal/involuted thymus group. In conclusion, CT may be used to distinguish LFH thymus from normal/involuted thymus in MG patients.

Unintended consequences of Mayo paraneoplastic evaluations

OBJECTIVE

To determine the proportion of true and false positives from paraneoplastic panels and effects on downstream testing/treatment.

METHODS

Using a retrospective cohort study design, we identified 500 consecutive patients with Mayo paraneoplastic autoantibody testing and performed chart abstraction. Paraneoplastic presentation types were categorized into probable, possible, and other by consensus. True positives were defined as a positive antibody titer with no other explanation found in addition to one of the following: syndrome known to be associated with the antibody, clinical improvement with treatment, and new malignancy. Comparisons of diagnostic testing and treatments between false and true positives were performed. Multivariable logistic regression was used to evaluate associations between patient-level factors and true positives.

RESULTS

The mean (SD) age of the population was 55.4 (17.1) years, and 55.4% were female, with 1.3 (1.2) years of follow-up. Of the 500 tests, 87 (17.4%, 95% confidence interval [CI] 14.1%-20.7%) were positive and 62 (71.3%, 95% CI 61.8%-80.8%) of these were false positives. Of those with a possible/other presentation (n = 369), 2 (0.5%, 95% CI 0.0%-1.0%) were true positives. CT of the chest (30.7% vs 11.8%, p ≤ 0.01) was performed more often in false positives than true negatives. Probable presentation type (odds ratio [OR] 57.9, 95% CI 12.5-268.0) and outpatient setting (OR 8.7, 95% CI 2.4-31.8) were associated with true-positive results.

CONCLUSION

Paraneoplastic tests result in a large proportion of false positives, particularly in those with clinical presentations that are not well established as paraneoplastic diseases. Future work should construct panels targeted to specific clinical presentations and ensure that tests are ordered in the appropriate clinical context.

Epidemiology of Myasthenia Gravis in Slovakia in the Years 1977-2015

PURPOSE

The objective of the study was to evaluate changes of epidemiological parameters in patients with myasthenia gravis (MG) in Slovakia during the period 1977-2015.

METHODS

Data from medical records of MG patients registered in Slovakia were analyzed. Epidemiological rates (incidence, prevalence, mortality) were assessed for several periods to identify changes and drifts over the period of study.

RESULTS

Out of 2,074 patients, 892 were males (43.0%) and 1,193 were females (57.0%). The thymoma associated MG (TAMG) was diagnosed in 123 patients (5.9%). The mean age at onset shifted from 35.8 years in 1977-1989 to 60.0 years in -2010-2015. The crude incidence increased from 0.36/100,000 in 1977-1989 to 1.74/100,000 in 2010-2015. The average annual incidence of TAMG was 0.05/100,000. Maximum increase of MG incidence was registered among the elderly (≥50 years), particularly in the group of patients in the age range 70-79 years (0.34/100,000 in 1977-1989→7.10/100,000 in 2010-2015) and 80-89 years (0.00/100,000 in 1977-1989→5.31/100,000 in 2010-2015). The crude MG prevalence on December 31, 2015 was 24.75/100,000. The average MG mortality was 0.27/100,000.

CONCLUSION

The age at onset and incidence increased significantly over the study period due to marked increase of MG incidence in elderly, particularly over 70 years. Possible reasons for this trend are discussed.

Gender and quality of life in myasthenia gravis patients from the myasthenia gravis foundation of America registry

INTRODUCTION

Quality of life (QOL) has been poorly characterized among patients with myasthenia gravis (MG) other than assessments performed within the clinical setting.

METHODS

Patients age ≥ 18 years who were diagnosed with MG and registered with the MG patient registry between July 1, 2013, and June 30, 2016, were included. Demographic information, disease related history, and QOL were compared between men and women using multivariable analysis.

RESULTS

A total of 1,315 subjects (827 women) were included. Women were significantly younger, had a younger age at symptom onset, and were more likely to have thymoma and thymectomy. The 15-item Myasthenia Gravis Quality of Life scale (MG-QOL15) was significantly worse in women. MG-QOL15 score was comparable between women who had thymectomy and men with or without thymectomy.

DISCUSSION

QOL among MG patients is worse in women compared with men, but this disparity is eliminated in women who have undergone thymectomy. Muscle Nerve, 2018.

Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome

PURPOSE OF REVIEW

This article discusses the pathogenesis, diagnosis, and management of autoimmune myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS).

RECENT FINDINGS

Recognition of new antigenic targets and improved diagnostic methods promise to improve the diagnosis of MG, although the clinical phenotypes associated with newer antibodies have not yet been defined. Future therapies might specifically target the aberrant immune response. The apparent increase in the prevalence of MG is not fully explained. Results of a long-awaited trial of thymectomy support the practice of performing a thymectomy under specific conditions.

SUMMARY

The current treatment options are so effective in most patients with MG or LEMS that in patients with refractory disease the diagnosis should be reconsidered. The management of MG is individualized, and familiarity with mechanisms, adverse effects, and strategies to manage these commonly used treatments improves outcome. Patient education is important. LEMS, frequently associated with an underlying small cell lung cancer, is uncommon, and the mainstay of treatment is symptomatic in most patients.

Surgical approach in thymectomy: Our experience and review of the literature

Aim

Thymectomy is the main treatment for thymoma and patients with myasthenia gravis (MG). The traditional approach is through a median sternotomy, but, recently, thymectomy through minimally invasive approaches is increasingly performed. Our purpose is an analysis and discussion of the clinical presentation, the diagnostic procedures and the surgical technique. We also consider post-operative complications and results, over a period of 5 years (May 2011–June 2016), in thymic masses admitted in our Thoracic Surgery Unit.

Methods

We analyzed 8 patients who underwent surgical treatment for thymic masses over a period of 5 years. 6 patients (75%) had thymoma, 2 patients (25%) had thymic carcinomas. 2 patients with thymoma (33%) had myasthenia gravis. We performed a complete surgical resection with median sternotomy as standard approach.

Results

One patient (12%) died in the postoperative period. The histological study revealed 6 (75%) thymoma and 2 (25%) thymic carcinomas. Post-operative morbidity occurred in 2 patients (25%) and were: pneumonia in 1 case (12%), atrial fibrillation and pleural effusion in 2 patients (25%). One patient with thymoma type A recurred at skeletal muscle 2-years after surgery.

Conclusions

Thymic malignancies are rare tumors. Surgical resection is the main treatment, but a multimodal approach is useful for many patients. Radical thymectomy is completed removing all the soft tissue in the anterior mediastinum between the two phrenic nerves and this is the most important factor in controlling myasthenia and influencing survival in patients with thymoma. Open (median sternotomy) approach has been the standard approach for thymectomy for the better visualization of the anatomical structures. Actually, video-assisted thoracoscopic surgery (VATS) thymectomy and robotic video-assisted thoracoscopic (R-VATS) approach versus open surgery has an equal if not superior oncological efficacy, better perioperative complications and survival outcomes.

Robotic versus thoracoscopic thymectomy: The current evidence

BACKGROUND

The purpose of this study was to analyze all relevant comparative studies comparing robot-assisted minimally invasive thymectomy (RATS) and video-assisted thoracic surgery thymectomy (VATS) in terms of surgical and short-term outcomes.

METHODS

A systematic search for articles describing robot-assisted and video-assisted thymectomy and addressing surgical outcomes, operation time, length of hospitalization, intra-operative blood loss, conversion to sternotomy and post-operative complications was performed using the medical databases.

RESULTS

Of the 478 studies from preliminary screening, five articles were included. By pooling these studies, we found no significant differences between the RATS and VATS (odds ratio 1.24 (95% CI 0.51, 3.03; p = 0.63)).There were no significant differences in comparison of conversion rates, operation time (26.29 min (95% CI -2.57, 55.35; p = 0.07)) and length of hospitalization (-1.58 days (95% CI -4.78, 1.62; p = 0.33)). There was a slightly higher blood loss in the RATS group.

CONCLUSION

Our meta-analysis did not detect any statistically significant differences in surgery outcomes between the two groups.

Surgical and oncological outcomes of thoracoscopic thymectomy for thymoma

Thymoma remains the most common primary anterior mediastinal neoplasm. Surgical resection remains central to the treatment of thymoma, with thoracoscopic thymectomy (TT) being increasingly performed. This present review article aimed to summarize current studies comparing TT and open thymectomy (OT). Recently, most patients with Masaoka stage I-II thymoma have been receiving TT. This procedure is associated with a significantly shorter post-operative hospital stay, decreased intraoperative blood loss, and fewer complications compared with OT. Recurrence rates of thymoma after TT range from 0% to 6.7%, and the 5-year disease-free survival (DFS) ranges from 83.3% to 96%. The oncological outcomes of TT are comparable to that of OT. Masaoka stage and the World Health Organization (WHO) type classification are valuable predictors of the prognosis of thymoma; hence, the optimal treatment for thymoma should be performed according to these two. TT is less invasive, with equivalent oncological outcomes, when compared with the OT. Minimally invasive surgery including TT for stage I-II thymomas is becoming the mainstay of therapy.

Comparative clinical outcomes after thymectomy for myasthenia gravis: Thoracoscopic versus trans-sternal approach

BACKGROUND

Thymectomy is an effective treatment option for long-term remission of myasthenia gravis. The superiority of the trans-sternal and thoracoscopic surgical approaches is still being debated. The aims of this study are to compare postoperative outcomes and neurologic outcomes between the two approaches and to identify prognostic factors for complete stable remission (CSR).

METHODS

Myasthenia gravis patients who underwent thymectomy with trans-sternal or thoracoscopic approach in MahaRaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand between January1, 2006 and December 31, 2013 were retrospectively reviewed. The endpoints were postoperative outcomes and cumulative incidence function for CSR. The analysis was performed using multilevel model, Cox's proportional hazard model, and propensity score.

RESULTS

Ninety-eight patients were enrolled in this study: 53 in the thoracoscopic group and 45 in the trans-sternal group. There were no significant differences between groups in composite postoperative complications, surgical time, ventilator support days, and length of intensive care unit stay. Intraoperative blood loss and length of hospital stay were significant less in the thoracoscopic group. The CSR and median time to remission were not significantly different between the two approaches. Prognostic factors for CSR were nonthymoma (hazard ratio: 3.5, 95% confidence interval: 1.01-12.22) and presence of pharmacological remission (hazard ratio: 24.3, 95% confidence interval: 3.27-180.41).

CONCLUSION

Thoracoscopic thymectomy is safe and provides good neurologic outcomes in comparison to the trans-sternal approach. Two predictive factors should be considered for CSR. Further prospective studies with a larger sample size and longer follow-up period are warranted to confirm these results.

Incidence and Prevalence of Myasthenia Gravis in Korea: A Population-Based Study Using the National Health Insurance Claims Database

Background and Purpose

There have been a few national population-based epidemiological studies of myasthenia gravis (MG) with wide variation of incidence and prevalence rates worldwide. Herein we report the first nationwide population-based epidemiological study of MG in Korea.

Methods

We attempted to estimate the incidence and prevalence rates of MG using the Korean National Health Insurance claims database for 2010 to 2013. Cases with MG were defined as those having claim records with a principal diagnosis of MG and the prescription of acetylcholinesterase inhibitors or immunosuppressive agents including corticosteroids and azathioprine within 2 years after the diagnosis. The year 2010 was set as a washout period, such that patients were defined as incident cases if their first records of MG were observed in 2011.

Results

In 2011 there were 1,236 incident cases, and the standardized incidence rate was 2.44 per 100,000 person-years. The standardized prevalence rates were 9.67 and 10.66 per 100,000 persons in 2010 and 2011, respectively. The incidence and prevalence rates peaked in the elderly population aged 60 to 69 years for both sexes.

Conclusions

This is one of the largest national population-based epidemiological studies of MG, and it has confirmed the high incidence and prevalence rates of MG in the elderly population of South Korea.

Myasthenia Crisis Induced by Pegylated-Interferon in Patient With Chronic Hepatitis C: A Case Report

Myasthenia gravis is occasionally associated with thymoma that needs surgical resection and may progress to severe respiratory failure. We experienced a rare case of myasthenia crisis during antiviral therapy for chronic hepatitis C, in whom mediastinal thymoma was discovered and successfully managed with surgical thymectomy and meticulous medical care.A 47-year-old-male patient complained of sudden diplopia 1 week after stopping 11-week administration of pegylated-interferon and ribavirin for chronic hepatitis C. Ophthalmologic examinations revealed ptosis on the right eyelid and restricted right eye movement. Myasthenia gravis was confirmed by positive repetitive nerve stimulation test and positive serum antiacetylcholine receptor antibody test, and mediastinal thymoma was found on chest CT scan. The ocular myasthenia gravis progressed to respiratory failure even after discontinuing antiviral treatment but eventually recovered with thymectomy, anticholinesterase administration, steroid pulse therapy, and prolonged ventilator care. We describe the clinical features of this life-threatening complication of interferon treatment along with previous myasthenia crisis cases by interferon for chronic hepatitis C.In patients with chronic hepatitis C who is going to receive interferon-based antiviral treatment, physicians need to keep in mind the potential life-threatening manifestations of myasthenia gravis before and during antiviral treatment especially when patients complain of muscular weakness and easy fatigability.

Video-assisted thoracoscopic surgery versus sternotomy in thymectomy for thymoma and myasthenia gravis

Thymectomy involves the removal of all the soft tissue in the pre-vascular plane of the anterior mediastinum between the two phrenic nerves. Surgical success in controlling myasthenia and the most important factor influencing survival in patients with thymoma depends on complete clearance of thymic tissue. Currently there is a perception that the open (median sternotomy) approach offers better visualisation of the thymic tissue. This perceived advantage is thought to justify the invasive nature of the procedure associated with increased morbidity. Video-assisted thoracoscopic surgery (VATS) for thymectomy has evolved significantly over the last decade, including bilateral and unilateral VATS (either left or right) approaches. The laterality of the approach remains largely on surgeon preferences, with the decision influenced by their experience and training. VATS offers superior illumination and magnification, particularly with the availability of advanced cameras with variable angles that provide better exposure and lighting of the operative field. The use of three-dimensional-operating imaging has also revolutionised the VATS technique. VATS thymectomy is a superior and radical technique in minimising access trauma and removing all thymic tissue that may be scattered in the anterior mediastinum and cervical fat. Other advantages of VATS include less intraoperative blood loss, early removal of chest drains, less requirement for blood products, decreased inflammatory cytokine response, shorter hospital stay and superior cosmesis. There is also a decreased risk of respiratory and cardiac related complications compared to the open (sternotomy) technique. Furthermore, no significant difference has been found in long-term complications and survival rate between VATS and open approaches. Subsequently, the VATS approach should be encouraged as more surgeons are adopting the minimally invasive practice as routine.

Behind and Beyond the Masaoka Staging: A 25-Year Follow-up Study of Tumor Recurrence in Completely Resected Thymic Epithelial Tumors in a Single Institution

We analyzed prognosticators for recurrence and post-recurrence survival in completely resected thymic epithelial tumors for the past 25 years in a single institution.Between June 1988 and December 2013, 238 patients undergoing intent-to-treat surgery for thymic epithelial tumors were reviewed. Sex, age, myasthenia gravis (MG), tumor histology, Masaoka staging, characteristic of locoregional invasion and recurrence, and the treatment for recurrence were collected. Comparison between groups was conducted using the Student t test and χ test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox proportional hazards model was used for univariate and multivariate analyses of prognostic factors.One hundred sixteen of 135 patients with completely resected thymoma and 35 of 56 patients with thymic carcinoma remained free of recurrence. In patients with completely resected thymoma, Masaoka staging, MG, tumor invasion into the lung, pericardium, and innominate vein or superior vena cava (SVC) invasion were associated with recurrence-free survival in univariate analysis (P = 0.004, 0.003, 0.001, 0.007, and 0.039, respectively). In multivariate analysis, MG was the positive independent prognosticator (P = 0.039). In patients with completely resected thymic carcinoma, Masaoka staging and innominate vein or SVC invasion were associated with recurrence-free survival in univariate analysis (P = 0.045 and 0.005, respectively), whereas innominate vein or SVC invasion was the negative independent prognosticator (P = 0.012). In patients with recurrent thymoma, those treated with surgery followed by chemotherapy had a significantly better post-recurrence survival than those undergoing chemoradiotherapy (P = 0.029) and those without treatment (P = 0.007). Patients with recurrent thymic carcinoma undergoing surgery followed by chemotherapy had a significantly better post-recurrence survival than those without treatment (P = 0.004), but not significantly better than those undergoing chemoradiotherapy (P = 0.252).In patients with completely resected thymoma, MG was the positive independent prognosticators of recurrence-free survival. Surgery should be attempted for recurrent disease for better post-recurrence survival. In patients with completely resected thymic carcinoma, innominate vein or SVC invasion was the negative independent prognosticator. Surgery for recurrence could be considered since it provided benefit for post-recurrence survival as chemoradiotherapy did.

Outcomes of Thymoma Treated with Multimodality Approach: A Tertiary Cancer Center Experience of 71 Patients

Aims

To explore the demographics and clinical outcome of patients with thymoma treated with a multimodality approach at our institute.

Methods

A total of 71 patients with thymoma (Masaoka stage II-IV and WHO subtype AB-B3) treated from 1999-2013 were included in this retrospective analysis. Age, stage, WHO subtypes, details of surgery, radiotherapy, and chemotherapy were noted. Progression-free survival (PFS) was estimated using Kaplan-Meier method and SPSS (version 21.0) was used for statistical analysis.

Results

Male:female ratio was 56:15 with median age at presentation of 41 years. Stage-wise distribution was 6:46:19 for stage II, stage III, and stage IV, respectively. A total of 31 patients (44%) had associated myasthenia gravis and 3 had pure red cell aplasia. A total of 57 patients (80%) underwent radical thymectomy and all of these patients received adjuvant radiotherapy. A total of 15 patients and 7 patients received adjuvant chemotherapy and neoadjuvant chemotherapy, respectively. At median follow-up of 19.3 months (range 7.9-72.3 months), 2-year and 3-year PFS rate for the entire cohort was 78.3% and 57.1%, respectively. On univariate analysis, surgery (hazard ratio [HR] 3.881; 95% confidence interval [CI] 1.784-19.220; p = 0.006) and stage (HR 5.457; 95% CI 1.567-18.996; p = 0.0001) were significant prognostic factors and association with myasthenia gravis (HR 0.404; 95% CI 0.151-1.078; p = 0.078) trended towards better PFS. Stage retained its prognostic significance (HR 5.501; 95% CI 2.076-14.573; p = 0.0006) on multivariate analysis.

Conclusions

Multimodality management of locally advanced thymoma yields decent survival outcomes. Masaoka stage is an independent prognostic factor for survival and radical surgery should be contemplated in all cases of locoregionally limited thymoma.

Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001-2012)

Background

Acquired myasthenia gravis (MG) in cats most commonly causes generalized weakness without megaesophagus and is more often associated with a cranial mediastinal mass, compared to dogs.

Hypothesis/Objectives

To extend the clinical findings described in the report of 2000 on MG in cats (J Am Vet Med Assoc 215:55–57).

Animals

Two hundred and thirty‐five cats with MG.

Methods

Retrospective case study to evaluate the long‐term outcome and incidence of spontaneous remission in myasthenic cats. Information including signalment, clinical presentation, presence of and type of cranial mediastinal mass, treatment including surgical versus medical, survival time, and outcome including spontaneous remissions was collected and analyzed in cats diagnosed at the Comparative Neuromuscular Laboratory, University of California San Diego by detection of acetylcholine receptor antibody titers >0.3 nmol/L by immunoprecipitation radioimmunosassay.

Results

Acquired MG in cats is associated with a euthanasia rate of 58%. Abyssinian and Somali cats had an increased incidence of MG compared to mixed breed cats or cats of other breeds. A cranial mediastinal mass, most commonly thymoma, was observed in 52% of the cats, which is higher than in the previous report. Spontaneous remission is not a characteristic of MG in cats.

Conclusions and clinical importance

Myasthenia gravis in cats is a chronic disease associated with a high incidence of a cranial mediastinal mass. Spontaneous remission is not common and clinicians should warn owners of the necessity for long‐term treatment. The clinical outcome with a cranial mediastinal mass did not differ between surgical or medical treatment.

Prevalence of factors associated with poor outcomes of hospitalized myasthenia gravis patients in Thailand

OBJECTIVE

To examine the prevalence of hospitalized myasthenia gravis (MG), and to determine the factors associated with poor outcomes of hospitalized MG patients at a national level.

METHODS

This study was based on a retrospective design. We collected data of hospitalized MG adults recorded by the National Health Security Office, Bangkok, Thailand between October 2009 and September 2010. Clinical data and treatment outcomes were examined.

RESULTS

The total number of hospitalized MG patients was 936 cases. The prevalence rate of hospitalized MG patients was 2.17/100,000 population. The average age (SD) was 44.93 (14.16) years. Regarding the discharge status of MG patients, 845 cases (90.3%) had improved. The total hospital charge of MG patients was 64,332,806 baht (USD 2,144,426.87) or an average of 68,731.63 baht/admission (USD 2,291.05), with an average length of stay of 10.45 days. There were 3 significant factors associated with poor outcomes in hospitalized MG patients; namely, hospital category, pneumonia, and respiratory failure.

CONCLUSION

The prevalence of admission in MG patients was 2.17 persons/100,000 population. Hospital category, pneumonia, and respiratory failure were significant factors associated with poor outcomes.

Neuro-Ophthalmology Annual Review

The aim of this study was to update the practicing ophthalmologist on the English-language neuro-ophthalmology literature from the prior year. This study is a review of English-language literature from August 1, 2012, to August 1, 2013. The authors searched PubMed articles published from August 1, 2012, to August 1, 2013, limited to English-language publications including original articles, review articles, and case reports and excluding letters to the editor, unpublished work, and abstracts. We researched the following topics: pupillary abnormalities, eye movement dysfunction, neuromuscular diseases, optic neuropathies, optic neuritis and demyelinating disease including multiple sclerosis, lesions of the chiasm and posterior primary visual pathways, elevated intracranial pressure, tumors and aneurysms affecting the visual pathways, vascular diseases, higher visual functions, and neuroimaging advances. We intend to share clinically relevant literature of the past year with the practicing ophthalmologist. We aimed to highlight remarkable and interesting literature rather than exhaustively including all new neuro-ophthalmological publications of the year. We reviewed literature in the past year with a focus on relevance and novelty. This review updates the comprehensive ophthalmologist on neuro-ophthalmic topics.

Myasthenia gravis and pregnancy

Myasthenia gravis is an autoimmune disease of the neuromuscular junction characterized by painless fluctuating skeletal muscle weakness. Disease exacerbations are more likely to occur in the first trimester or puerperium. A number of medications commonly used in obstetric practice can exacerbate the disease. The effect of pregnancy on myasthenia varies substantially from woman to woman and also from pregnancy to pregnancy in the same woman. Mainstay treatments involve acetylcholine esterase inhibitors, corticosteroids and other immunosuppressants, and adequate rest. Newborns may suffer in utero or neonatal consequences, usually transient, of transplacental antibody exposure.