Autoimmune disorders and paraneoplastic syndromes in thymoma

Anticancer therapy-induced peripheral neuropathy in solid tumors: diagnosis, mechanisms, and treatment strategies

Anticancer therapy-induced peripheral neuropathy (PN) is a common adverse event during the diagnosis and treatment of solid tumors. The drug class, cumulative dose, and individual susceptibility affect the incidence and severity of PN. Owing to the lack of specific biomarkers and imaging tests, the diagnostic criteria for PN remain unclear. Moreover, the available and effective clinical treatment strategies are very limited, and most of the current drugs focus on symptom management rather than fundamental reversal of the disease course. The morbidity mechanisms of PN are diverse, including direct neurotoxicity, mitochondrial dysfunction, and disruption of axonal transport. Here, we summarize the diagnosis, mechanisms, and neuroprotective strategies of PN and discuss potential intervention treatments.

Development of thymoma without myasthenia gravis in a patient with radiographic axial spondyloarthritis treated with tumor necrosis factor-α inhibitors

Thymic tumors are rare in the general population, and to the best of our knowledge, no cases of thymoma have been described in patients with rheumatic diseases treated with tumor necrosis factor (TNF)-α inhibitors, except the case of a patient receiving infliximab for Crohn's disease (CD) who developed a B2 thymoma. We describe a 60-year-old Caucasian male with radiographic axial spondyloarthritis (r-axSpA) and CD who developed an AB-type thymoma without myasthenia gravis after 18 years of treatment with TNF-α inhibitors. The patient had received the same molecule since the r-axSpA/CD diagnosis and changed it 6 months before the diagnosis of thymoma due to a disease flare. At the time of the drug switch, no mediastinal mass was present on the chest X-ray. The thymoma was surgically removed, and no additional therapy was needed. Treatment with TNF-α inhibitors was reintroduced after surgery. This case raises some important questions that remain open and deserve to be addressed in the future, such as the association between immunosuppressive therapy and thymoma and the controversial relationship between TNF-α inhibitors and myasthenia gravis.

Intestinal failure from thymoma-associated autoimmune enteropathy: a rare case report

We describe a case of altered bowel habit, early satiety, anorexia and weight loss caused by autoimmune enteropathy. This diagnosis was confirmed by biopsies obtained from upper gastrointestinal endoscopy and ileocolonoscopy. Further investigations revealed multiple pulmonary nodules which were metastases from a malignant thymoma. The patient was commenced on oral budesonide and Mesalazine, in addition to oral and enteral supplementation driven by the specialist nutrition support team, but she did not achieve histological remission, nor did she demonstrate improvement in her nutritional status. She received 3-weeks of in-patient parenteral nutrition, but then subsequently deteriorated as she declined home parenteral nutrition. The patient died eight months later from complications of her disease. This case highlights the rare manifestation of metastatic thymoma presenting with autoimmune enteropathy that led to intestinal failure and death.

Rising Threat: Long-Term Trends in the Incidence and Mortality of Thymic Epithelial Tumor

INTRODUCTION

An upward trend in the incidence of thymic epithelial tumors (TETs) has been reported over the past few decades, but because of its rarity, little is currently known about its epidemiological trends. This study examined temporal trends in the incidence and mortality of TETs in the US and explored these trends in population subgroups while investigating important factors that influence their prognosis.

METHODS

A retrospective, population-based study was conducted using nationally representative data from the Surveillance, Epidemiology, and End Results program, and 4979 patients diagnosed with TETs from 2000 to 2020 were evaluated. Associated population data were used to determine age-adjusted incidence and mortality, and 5-year TET-specific mortality (SM). Trends were assessed for the entire cohort, as well as for particular subgroups, including thymoma and thymic carcinoma.

RESULTS

From 2000 to 2020, the overall incidence and mortality of TETs were 2.769 and 1.203 per million person-years, respectively. Both the age-adjusted incidence and mortality of TETs increased over the study period, with increases occurring across almost all ethnic groups, histological subtypes, and stages. Multivariate analysis revealed that age, World Health Organization histological type (B1, B2, and B3 thymoma and thymic carcinoma), Masaoka-Koga stage (IIB and III/IV), maximum tumor diameter (5-10 and > 10 cm), surgery, and chemotherapy were independently associated with TET-SM.

CONCLUSIONS

The incidence and mortality of TETs have steadily increased over time, and these trends might be related to the widespread use of computed tomography for lung cancer screening and the increasing number of TETs found incidentally. The study also identified several important factors independently associated with TET-SM, suggesting that early diagnosis and surgical intervention are critical to achieving good prognoses.

Identification and characteristics of a novel CD8αα T cell subset in a refractory myasthenia gravis patient

Myasthenia gravis (MG) is an autoimmune disease that impairs neuromuscular transmission. Autoantibodies and cellular immunity mediate the immunopathology of MG, yet the mechanism of CD8+ T cells in this process remains elucidated. In this study, we discovered a novel subset of CD8αα+ T cells in the peripheral blood of an 18-year-old Chinese man diagnosed as MG, who has undergone thymectomy and persistent myasthenia crisis. Designated as CD161neg T cell, this subset was characterized by TCRαβ+CD8αα+PLZF+Vα7.2+ but notably lacked CD161, distinct from mucosal-associated invariant T (MAIT) cells known for high CD161. The patient exhibited unusually high levels of CD161neg T cells compared to other MG patients, which fluctuated with infections but not MG severity. RNA sequencing revealed that CD161neg T cells lacked the genes characteristic of mature MAIT cells including CCR6, CXCR6, ZBTB16, and IL18RAP, but expressed cytotoxic T cell-related genes GZMH and IFNG. This study shed new light on the heterogeneity and complexity of CD8αα+ T cells in MG patients with thymoma.

Thymoma-Induced Severe Biventricular Failure without Myasthenia Gravis: Investigating Tachycardia-Induced Cardiomyopathy

BACKGROUND Cardiomyopathy associated with thymoma is thought to be a cardiac manifestations of myasthenia gravis (MG). However, there are case reports of newly diagnosed thymoma presenting with cardiomyopathy without MG, and the mechanism remains unclear. The purpose of this report is to explore tachycardia-induced cardiomyopathy (TIC) as a potential mechanism for cardiomyopathy in thymoma without features of MG. CASE REPORT A 31-year-old man presented with atrial flutter with right bundle branch block and severe biventricular heart failure. Echocardiogram revealed severe left ventricle ejection fraction (LVEF) of 15% with biventricular dilation with impaired systolic function. Computer tomography coronary angiography demonstrated normal coronary artery disease. Cardiac magnetic resonance imaging showed normal T1 and T2 mapping, without inflammation or edema. A large anterior mediastinal mass was found on computer tomography chest. Mediastinal mass biopsy identified type B3 thymoma (WHO classification) with dual population of large, uniform epithelial thymic cells and immature T cell phenotype. Acetylcholine receptor antibody was positive without clinical features of MG and hypogammaglobulinemia indicating Good syndrome. He was treated with antiarrhythmic and heart failure pharmacotherapy, carboplatin and paclitaxel, and intravenous immunoglobulin. He demonstrated reversible heart failure following abolishment of tachyarrhythmia, consistent with tachycardia-induced cardiomyopathy. CONCLUSIONS We report a rare case of a newly diagnosed thymoma and Good syndrome without clinical features of MG presenting with tachyarrhythmia and severe biventricular failure. The reversibility of the cardiomyopathy following abortion of tachyarrhythmia with treatment highlights TIC as a potential cause.

Incidence, characteristics, and comorbidities of a complete unselected Danish cohort of patients with thymic epithelial tumors

BACKGROUND AND PURPOSE

We report the incidence, characteristics, and comorbidities of the complete unselected Danish cohort of patients with thymic epitheliums (TETs), which may serve as evidence for guiding treatment, surveillance, and counselling of TET patients.

PATIENTS AND METHODS

All patients diagnosed with TETs from January 1st, 2015, to December 31st, 2020, were identified using the Danish Pathology Data Registry. Data on patient characteristics, comorbidities, and tumor histology were collected from electronic medical records available for all patients.

RESULTS

The cohort consisted of 283 patients with a mean age of 64 years (SD: 12). The crude rate was 8.2/1,000,000 TETs annually, thus higher than the age-standardized rates of 4.8/1,000,000 in the WHO World Standard Population and 6.1/1,000,000 in the European Standard Population. Thymomas were diagnosed in 240 patients (85%) (9% type A, 31% AB, 18% B1, 26% B2, 6% B3, 5% micronodular, 0.4% metaplastic, and 5% of unspecified subtype), thymic carcinomas in 39 patients (14%), and thymic neuroendocrine tumors in 4 patients (1.4%). Tumors in Tumour, Node, Metastasis (TNM) stage I were diagnosed in 181 patients (64%) and were mostly thymomas (72%). Prior to TET diagnosis, 91 (32%) patients presented with autoimmune disorders (19% myasthenia gravis) and 82 patients (29%) had at least one cancer diagnosis.

INTERPRETATION

We found a higher incidence of TETs in Denmark than in previous European population-based studies, while reporting a similar distribution of histological types and tumor stages. Furthermore, we found an increased prevalence of autoimmune disorders and cancers in the cohort before TET diagnosis compared to the general population.

A Clinical Case of Thymoma Presenting With Pure Erythroid Aplasia

Thymic tumors are a rare condition that affects both genders equally, typically presenting between the ages of 40 and 70. Although often asymptomatic, they can give rise to paraneoplastic syndromes, with myasthenia gravis being the most common. The presentation of pure red cell aplasia, however, remains an uncommon manifestation. Thymectomy is the primary treatment, but it may not always be sufficient for managing associated syndromes, and immunosuppressive therapy may be necessary. This case involves a 50-year-old, otherwise healthy man, who presented to the emergency department with progressive dyspnea and asthenia over the course of one month. A mediastinal mass and hypoproliferative normocytic, normochromic anemia were identified, and after a diagnostic work-up, it was concluded to be a case of thymoma with associated pure red cell aplasia. The patient underwent surgery and radiotherapy and received immunosuppressive therapy. This case highlights a rare manifestation of an uncommon pathology, underscoring the need for a multidisciplinary approach and the challenges in treatment.

Cardiovascular disease in thymic cancer patients

Introduction

Cancer patients may have increased risk for adverse cardiac events, but our understanding of cardiovascular risk in thymic cancer patients is not clear. We sought to characterize baseline cardiometabolic risk factors before thymic cancer diagnosis and the potential association between cancer treatment and subsequent cardiac events.

Methods

This was a retrospective cohort study evaluating patients with thymic cancer from 2003 to 2020 compared to age- and sex-matched controls without cancer. Baseline cardiovascular risk factors, cancer characteristics, and incidence of cardiac events were collected from the health information exchange. Multivariable regression was used to examine the impact of cardiovascular risk factors and cancer therapies.

Results

We compared 296 patients with pathology-confirmed thymic cancer to 2,960 noncancer controls. Prior to cancer diagnosis, thymic cancer patients (TCPs) had lower prevalence of hypertension, dyslipidemia, and diabetes mellitus and similar rates of obesity, tobacco use, and pre-existing cardiovascular disease (CVD) compared to controls. After diagnosis, high-risk TCPs (>2 cardiovascular risk factors or pre-existing CVD) had higher risk for cardiac events (HR 3.73, 95% CI 2.88-4.83, p < 0.001). In the first 3 years after diagnosis, TCPs had higher incidence of cardiac events (HR 1.38, 95% CI 1.01-1.87, p = 0.042). High-risk TCPs who received radiotherapy or chemotherapy had higher risk of cardiac events (HR 4.99, 95% CI 2.30-10.81, p < 0.001; HR 6.24, 95% CI 2.84-13.72, p < 0.001).

Discussion/conclusion

Compared to noncancer controls, TCPs experienced more cardiac events when adjusted for risk factors. Patients with multiple cardiovascular risk factors receiving radiotherapy or chemotherapy had higher incidence of cardiac events.

Research progress of malignant peritoneal mesothelioma with paraneoplastic syndrome: A review

Malignant peritoneal mesothelioma (MPM) is a rare and invasive tumor, and some patients will develop paraneoplastic syndrome (PS) during the course of the disease. This review summarizes PS associated with MPM, focusing on the clinical characteristics and treatment progress in hematological, endocrine, rheumatic, neurological, urinary, and other systems to decrease missed diagnosis and misdiagnosis, help early diagnosis and prompt treatment, and provide guidance for the clinical decision-making of this kind of patients.

Peripheral nervous system immune-related adverse events due to checkpoint inhibition

Immune checkpoint inhibitors have revolutionized cancer therapy and are increasingly used to treat a wide range of oncological conditions, with dramatic benefits for many patients. Unfortunately, the resulting increase in T cell effector function often results in immune-related adverse events (irAEs), which can involve any organ system, including the central nervous system (CNS) and peripheral nervous system (PNS). Neurological irAEs involve the PNS in two-thirds of affected patients. Muscle involvement (immune-related myopathy) is the most common PNS irAE and can be associated with neuromuscular junction involvement. Immune-related peripheral neuropathy most commonly takes the form of polyradiculoneuropathy or cranial neuropathies. Immune-related myopathy (with or without neuromuscular junction involvement) often occurs along with immune-related myocarditis, and this overlap syndrome is associated with substantially increased mortality. This Review focuses on PNS adverse events associated with immune checkpoint inhibition. Underlying pathophysiological mechanisms are discussed, including antigen homology between self and tumour, epitope spreading and activation of pre-existing autoreactive T cells. An overview of current approaches to clinical management is provided, including cytokine-directed therapies that aim to decouple anticancer immunity from autoimmunity and emerging treatments for patients with severe (life-threatening) presentations.

[Pure white cell aplasia combined with thymoma and lung cancer: a case report and literature review]

Pure white cell aplasia (PWCA) is a rare hematologic disorder. In this case study, a 67-year-old man presented with severe neutropenia along with thymoma and lung cancer. A comprehensive diagnostic approach was done which included routine blood test, bone marrow cytology, bone marrow pathology, flow cytometry, and thymic pathology. Other potential causes, such as pure red blood cell aplasia and myelodysplastic syndrome, were ruled out. The final diagnosis was determined to be thymoma-related PWCA. Continuous treatment with human granulocyte colony-stimulating factor (G-CSF) was ineffective for treating PWCA in this patient. The patient's white blood cell and neutrophil count increased following treatment with cyclosporine and subsequently returned to normal levels by the 8th day after thymectomy. A recurrence of PWCA was identified 40 days after the operation and coincided with COVID-19 infection. The patient eventually succumbed to a severe infection. Therefore, in cases of severe neutropenia with an unclear etiology, prompt evaluation of mediastinal and bone marrow status is imperative.

Coexistence of myasthenia gravis and lichen planus: A case report and systematic review of related case reports from 1971 to 2024

Key Clinical Message

The co-occurrence of myasthenia gravis (MG) and lichen planus (LP) is a rare phenomenon, with only 13 cases reported in the English literature between 1971 and 2024. Patients with MG or LP, regardless of the thymoma status, require close monitoring for other autoimmune diseases.

Abstract

Myasthenia gravis (MG) is an uncommon autoimmune disease, resulting in fatigable muscle weakness in the ocular, bulbar, and respiratory muscles, as well as muscles of the extremities. Lichen planus (LP) is an autoimmune mucocutaneous disease, presenting with pruritic and violaceous plaques on the skin and mucosal surfaces. So far, MG and LP co-occurrence is only reported in anecdotal individuals. This study reports a patient with MG and LP and systematically reviews the English literature on this rare co-occurrence from 1971 to 2024, indicating only 13 cases with similar conditions. A 67-year-old man presented with ocular and progressive bulbar symptoms, a year after being diagnosed with generalized LP. Laboratory evaluations were normal except for the high anti-AchR-Ab titer and a positive ANA titer. Neurologic examinations revealed asymmetric bilateral ptosis, weakness and fatigability in proximal muscles, and a severe reduction in the gag reflex. He was diagnosed with late-onset, seropositive MG. The treatment included pyridostigmine (60 mg, three times daily), intravenous immunoglobulin (25 g daily for 5 days), and oral prednisolone. There was no evidence of thymoma in the chest x-ray and CT scan without contrast. However, a CT scan with contrast was not performed due to the patient's unstable condition. A common autoimmune mechanism may underlie the unclear pathophysiology of MG and LP co-occurrence, with or without thymoma. Patients with MG, LP, or thymoma require close monitoring and assessment for other possible autoimmune diseases.

Immune tolerance and the prevention of autoimmune diseases essentially depend on thymic tissue homeostasis

The intricate balance of immune reactions towards invading pathogens and immune tolerance towards self is pivotal in preventing autoimmune diseases, with the thymus playing a central role in establishing and maintaining this equilibrium. The induction of central immune tolerance in the thymus involves the elimination of self-reactive T cells, a mechanism essential for averting autoimmunity. Disruption of the thymic T cell selection mechanisms can lead to the development of autoimmune diseases. In the dynamic microenvironment of the thymus, T cell migration and interactions with thymic stromal cells are critical for the selection processes that ensure self-tolerance. Thymic epithelial cells are particularly significant in this context, presenting self-antigens and inducing the negative selection of autoreactive T cells. Further, the synergistic roles of thymic fibroblasts, B cells, and dendritic cells in antigen presentation, selection and the development of regulatory T cells are pivotal in maintaining immune responses tightly regulated. This review article collates these insights, offering a comprehensive examination of the multifaceted role of thymic tissue homeostasis in the establishment of immune tolerance and its implications in the prevention of autoimmune diseases. Additionally, the developmental pathways of the thymus are explored, highlighting how genetic aberrations can disrupt thymic architecture and function, leading to autoimmune conditions. The impact of infections on immune tolerance is another critical area, with pathogens potentially triggering autoimmunity by altering thymic homeostasis. Overall, this review underscores the integral role of thymic tissue homeostasis in the prevention of autoimmune diseases, discussing insights into potential therapeutic strategies and examining putative avenues for future research on developing thymic-based therapies in treating and preventing autoimmune conditions.

Evaluation of Genetic or Cellular Impairments in Type I IFN Immunity in a Cohort of Young Adults with Critical COVID-19

Several genetic and immunological risk factors for severe COVID-19 have been identified, with monogenic conditions relating to 13 genes of type I interferon (IFN) immunity proposed to explain 4.8% of critical cases. However, previous cohorts have been clinically heterogeneous and were not subjected to thorough genetic and immunological analyses. We therefore aimed to systematically investigate the prevalence of rare genetic variants causing inborn errors of immunity (IEI) and functionally interrogate the type I IFN pathway in young adults that suffered from critical COVID-19 yet lacked comorbidities. We selected and clinically characterized a cohort of 38 previously healthy individuals under 50 years of age who were treated in intensive care units due to critical COVID-19. Blood samples were collected after convalescence. Two patients had IFN-α autoantibodies. Genome sequencing revealed very rare variants in the type I IFN pathway in 31.6% of the patients, which was similar to controls. Analyses of cryopreserved leukocytes did not indicate any defect in plasmacytoid dendritic cell sensing of TLR7 and TLR9 agonists in patients carrying variants in these pathways. However, lymphocyte STAT phosphorylation and protein upregulation upon IFN-α stimulation revealed three possible cases of impaired type I IFN signaling in carriers of rare variants. Together, our results suggest a strategy of functional screening followed by genome analyses and biochemical validation to uncover undiagnosed causes of critical COVID-19.

Thymus as Incontrovertible Target of Future Immune Modulatory Therapeutics

Thymus plays a crucial role in cellular immunity by acting as a warehouse for proliferating and differentiating lymphocytes. Thymic stromal cells educate T-cells to differentiate self from non-self antigens while nurse cells and thymoproteasome play a major role in the maturation and differentiation of T-cells. The thymic conditions dictate T-cells to cope with the risk of cancer development. A study was designed to demonstrate potential mechanisms behind the failure to eliminate tumors and impaired immune surveillance as well as the impact of delay in thymus regression on cancer and autoimmune disorders. Scientific literature from Pubmed; Scopus; WOS; JSTOR; National Library of Medicine Bethesda, Maryland; The New York Academy of Medicine; Library of Speech Rehabilitation, NY; St. Thomas' Hospital Library; The Wills Library of Guys Hospital; Repository of Kings College London; and Oxford Academic repository was explored for pathological, physiological, immunological and toxicological studies of thymus. Studies have shown that systemic chemotherapy may lead to micro inflammatory environment within thymus where conventionally and dynamically metastasized dormant cells seek refuge. The malfunctioning of the thymus and defective T and Treg cells, bypassing negative selection, contributes to autoimmune disorders, while AIRE and Fezf2 play significant roles in thymic epithelial cell solidity. Different vitamins, TCM, and live cell therapy are effective therapeutics. Vitamin A, C, D, and E, selenium and zinc, cinobufagin and dietary polysaccharides, and glandular extracts and live cell injections have strong potential to restore immune system function and thymus health. Moreover, the relationship between different ages/ stages of thymus and their corresponding T-cell mediated anti-tumor immune response needs further exploration.

Thymic Epithelial Tumor and Immune System: The Role of Immunotherapy

Thymic epithelial tumors (TETs) comprise a rare group of thoracic cancers, classified as thymomas and thymic carcinomas (TC). To date, chemotherapy is still the standard treatment for advanced disease. Unfortunately, few therapeutic options are available for relapsed/refractory tumors. Unlike other solid cancers, the development of targeted biologic and/or immunologic therapies in TETs remains in its nascent stages. Moreover, since the thymus plays a key role in the development of immune tolerance, thymic tumors have a unique biology, which can confer susceptibility to autoimmune diseases and ultimately influence the risk-benefit balance of immunotherapy, especially for patients with thymoma. Indeed, early results from single-arm studies have shown interesting clinical activity, albeit at a cost of a higher incidence of immune-related side effects. The lack of knowledge of the immune mechanisms associated with TETs and the absence of biomarkers predictive of response or toxicity to immunotherapy risk limiting the evolution of immunotherapeutic strategies for managing these rare tumors. The aim of this review is to summarize the existing literature about the thymus's immune biology and its association with autoimmune paraneoplastic diseases, as well as the results of the available studies with immune checkpoint inhibitors and cancer vaccines.

Thymoma-associated autoimmune encephalitis: Analysis of factors determining prognosis

INTRODUCTION

Autoimmune encephalitis (AE) is a heterogeneous group of inflammatory central nervous system disorders caused by a misdirected immune response against self-antigens expressed in the central nervous system. The thymus is a central organ in the immune system and thymic tumors are thought to be possible initiators of many neurological disorders. Recently, there is growing evidence that thymomas are associated with autoimmune encephalitis.

AIMS

Our study initially explored the characteristics of patients with autoimmune encephalitis combined with thymoma.

METHODS

We used patient data from January 1, 2011 to October 1, 2021 from the PubMed, Web of Science, Ovid, and CNKI platforms to analyze overall demographics, frequency of symptoms and associations, and treatment prognosis outcomes.

RESULTS

A total of 68 patients were included. There were 39 female cases (57.4%). The mean age was 50 years (IQR 40-66 years). All had acute and subacute onset. The clinical manifestations were mostly cognitive changes (70.6%), mental disorders (57.4%), and epilepsy (50.0%). The most common neuronal antibody was alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Magnetic resonance imaging (MRI) abnormalities were present in 81.0% of patients, mostly in the hippocampus, temporal lobe, and some in cortical and subcortical areas. Abnormalities in the electroencephalogram (EEG) in 69.8% of patients. Treatment involved immunotherapy and thymoma treatment, with 79.7% of patients improving after treatment. While 20.3% of patients had a poor prognosis. Further, 14.8% of patients relapsed. Mental disorders, autonomic dysfunction, sleep disturbances, anti-Ma2, and thymoma untreated were more frequent in patients with poor prognosis.

CONCLUSION

Thymoma-associated autoimmune encephalitis is a unique disease entity. Long-term follow-up of chest CT findings is recommended for patients with autoimmune encephalitis.

COVID-19-associated AMPA-R and CRMP-5 autoimmune encephalitis in a patient with thymoma and myasthenia gravis

Thymomas are associated with autoimmune disease, most commonly myasthenia gravis, and rarely with autoimmune encephalitis. More recently, viral triggers including COVID-19 have also been implicated in autoimmunity. We present a case of antibody-positive autoimmune encephalitis that developed in the setting of COVID-19 in a patient with thymomatous myasthenia gravis.

Anti-titin antibodies are associated with myocarditis in patients with myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) can affect cardiac muscles with variable presentations. Myocarditis is a rare but potentially serious cardiac manifestation of MG. Although thymomas and anti-titin antibodies have been suggested as risk factors for myocarditis in patients with MG, their independent influence on myocarditis has rarely been assessed.

METHODS

A retrospective chart review was conducted on 247 patients diagnosed with MG who were tested for anti-titin antibodies. Myocarditis was diagnosed on the basis of the European Society of Cardiology 2013 Task Force criteria for clinically suspected myocarditis. Patients were classified into myocarditis-positive and myocarditis-negative groups. Multivariate analysis was performed to analyze the risk factors for myocarditis.

RESULTS

Of the 247 patients, 25 (10.1%) were myocarditis-positive and 222 (89.9%) were myocarditis-negative. Anti-titin antibody positivity was higher in the myocarditis-positive group than in the myocarditis-negative group (68.0% vs. 28.4%, p < 0.001). A history of MG crisis was more frequent in the myocarditis-positive group than in the myocarditis-negative group (64.0% vs. 10.4%, p < 0.001). The presence of anti-titin antibodies (odds ratio [OR] 7.906; confidence interval [CI] 2.460-25.401) and MG crisis (OR 24.807; CI 7.476-82.311) was significantly associated with myocarditis. The Cox regression model showed that the anti-titin antibody levels (hazard ratio [HR] 3.639; 95% CI 1.557-8.505) and MG crisis (HR 6.137; 95% CI 2.639-14.272) were significant risk factors for the development of myocarditis.

CONCLUSION

The presence of anti-titin antibody was associated with myocarditis in patients with MG, whereas thymoma was not. Although rare, early suspicion of myocarditis could be required, especially in patients with MG having anti-titin antibodies.

Concurrent de novo Thymoma-associated Paraneoplastic Type 1 Autoimmune Hepatitis and Pure Red Cell Aplasia after Thymectomy: A Case Report and Literature Review

The precise manipulation of immune tolerance is the holy grail of immunotherapies for both autoimmunity and cancer immunity. Thymomas are well known to be associated with autoimmune diseases. The exact mechanism by which autoreactivity is induced after thymectomy remains to be elucidated. We herein present the case of a 50-year-old lady with concurrent de novo type 1 autoimmune hepatitis (AIH) and pure red cell aplasia (PRCA), 1 month after undergoing a successful total thymectomy for combined squamous cell carcinoma and thymoma (Masaoka stage II). Corticosteroids yielded short-term effects for both AIH and PRCA. Literature on thymoma-associated AIH, an extremely rare immune-related comorbidity, was also reviewed.

Two Very Rare Cases of Metastatic Thymic Carcinoma with Sjogren's Syndrome: A Case Series

Thymic tumours are rare thoracic malignancies with thymic carcinoma accounting for approximately 12% of all thymic tumours compared to thymomas which account for approximately 86%. Unlike thymomas, it is very rare for thymic carcinomas to be associated with autoimmune disorders or paraneoplastic syndromes. When these phenomena do occur, the vast majority are myasthenia gravis, pure red cell aplasia, or systemic lupus erythematous. Paraneoplastic Sjogren's syndrome is a rare complication of thymic carcinoma, with only two cases previously reported. Here we present 2 cases of patients with metastatic thymic carcinoma who developed autoimmune phenomena consistent with Sjogren's syndrome without classical symptoms prior to treatment. One patient opted for surveillance of their malignancy, while the other underwent chemoimmunotherapy with favourable results. These case reports describe two distinctive clinical presentations of a rare paraneoplastic phenomenon.

Thymoma With Triple Threat: Pure Red Cell Aplasia, Autoimmune Hemolytic Anemia, and T-Cell Large Granular Lymphocytic Leukemia

Thymomas are a rare neoplasm of the anterior mediastinum and often associated with paraneoplastic syndromes. Though myasthenia gravis is the most common and well-known, the list of reported paraneoplastic syndromes occurring with thymoma is extensive and ever-growing. Paraneoplastic syndromes can involve nearly every organ system, including hematologic abnormalities affecting any or all cell lines. This can present challenges to the clinician in terms of diagnosis, prognostic impact, and management. We present the case of a previously healthy 41-year-old female who was diagnosed with thymoma and three rare hematologic paraneoplastic syndromes: pure red cell aplasia (PRCA), autoimmune hemolytic anemia (AIHA), and T-cell large granular lymphocytic leukemia (T-LGLL). To the best of our knowledge, there have been only four other reported cases of PRCA and AIHA in a single patient with thymoma, all of which were treated with thymectomy. Upfront surgical resection was not possible in the present case and thus the patient was alternatively treated with corticosteroids and octreotide, which proved successful in resolving the anemia. The authors present this case to share these findings of an alternative treatment strategy for thymoma-associated PRCA and AIHA and to highlight the importance of careful monitoring with routine blood work for these complex patients.

Hypofractionated Radiation Therapy Combined With Weekly Chemotherapy in Patients With Unresectable or Recurrent Thymic Epithelial Tumor: A Prospective, Single-Arm Phase 2 Study (GASTO-1042)

PURPOSE

This prospective phase 2 study aimed to evaluate the efficacy and safety of hypofractionated radiation therapy (HRT) combined with concurrent weekly chemotherapy in patients with unresectable or recurrent thymic epithelial tumors (TETs).

METHODS AND MATERIALS

Patients with unresectable or recurrent intrathoracic TETs that could be encompassed within the radiation fields were enrolled. HRT using intensity modulated radiation therapy (IMRT) technique was administered with 3 different levels of radiation doses (51 Gy/17 fractions (fx), 48 Gy/12 fx, and 45 Gy/9 fx; biologically effective dose of 66.3-67.5Gy), combined with weekly docetaxel (25 mg/m²) and nedaplatin (25 mg/m²). Weekly thymosin α1 (1.6 mg) was administered from the start to 2 months after radiation therapy. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), health-related quality of life (QOL), and toxicity were recorded.

RESULTS

Fifty eligible patients enrolled from August 1, 2018, to July 1, 2020, were analyzed. Most patients (82.0%) had stage IVB tumors. Patients had IMRT-HRT (36-51 Gy in 9-17 fx, median biologically effective dose of 67.2 Gy) and concurrent weekly docetaxel/nedaplatin (2-4 cycles). During a median follow-up of 25.0 months (14.0-40.0), the ORR was 83.7%, the 2-year PFS was 59.1%, and the 2-year OS was 90.0%. There was 1 (2.0%) in-field recurrence while 19 (38.0%) patients developed out-of-field recurrence. Grade 3 pneumonitis was observed in 1 patient (2.0%). The ORR, 2-year PFS, 2-year OS, and toxicity were similar among 3 dose levels. Fourteen (28.0%) patients had 2 to 4 courses of radiation therapy because of recurrent diseases. Only 1 suffered from grade 1 pulmonary fibrosis during follow-up. Most patients (88%) maintained a stable QOL within 1 year after radiation therapy.

CONCLUSIONS

IMRT-HRT and concurrent weekly docetaxel/nedaplatin was effective and well tolerated in unresectable or recurrent TETs. Considering the common out-of-field recurrence, this combined regimen could be an option for repeated radiation therapy. Thymosin α1 might help lower the incidence of pneumonitis and maintain the QOL.

Identification of Immune-Related Hub Genes in Thymoma: Defects in CD247 and Characteristics of Paraneoplastic Syndrome

Background: Thymomas (Ts) and thymic carcinomas (TCs) are rare primary tumors of the mediastinum. Paraneoplastic syndrome (PNS) is an important feature of thymoma, which presents great challenges to clinicians.

Methods: The present study uses the weighted gene co-expression network analysis (WGCNA) to identify possible immunologic mechanisms of thymoma. RNA sequencing data from thymoma samples were downloaded from the TCGA. Core genes were taken from the module that is closely related to the WHO’s stage of classification. Enhanced analysis using the online database “Metascape” and an overall survival (OS) analysis were carried out via the Kaplan–Meier method. The hub genes were obtained from the protein–protein interaction (PPI) network. In addition, we jointly analyzed multiple sets of PNS data related to thymomas from other sources to verify the correlation between thymomas and PNS. The impact of hub genes on the prognosis of PNS was evaluated via the ROC curve, with simultaneous analysis of immune infiltration by CIBERSORT.

Findings: The 14 immune hub genes closely related to thymomas were found to be jointly involved in the T-cell receptor signaling pathway. Compared to the normal thymus and type B1/B2 thymoma, there is a lower number of T-cells in type A/B3 thymoma and thymic carcinoma. The expression of genes related to the T-cell receptor signaling pathway appeared defective. The low expression of CD247 and the decrease in the number of mature T-cells are common features among thymomas, specific pulmonary fibrosis, rheumatoid arthritis, and systemic lupus erythematosus.

Diagnostic Challenges in the Cytology of Thymic Epithelial Neoplasms

Simple Summary

Thymic epithelial neoplasms, including thymoma, thymic carcinoma, and thymic neuroendocrine neoplasms, constitute the majority of anterior mediastinal masses. Fine needle aspirations (FNA) of mediastinal masses are infrequently encountered and are highly challenging to interpret. Thymic neoplasms display a significant degree of histologic diversity and have overlapping morphologic features with tumors from other sites. However, when properly interpreted alongside ancillary studies and radiologic findings, FNAs can yield clinically actionable results. This review aims to illustrate the usefulness and diagnostic pitfalls of thymic FNAs to assist pathologists in analyzing these specimens.

Abstract

Thymic epithelial neoplasms are rare tumors that constitute the majority of anterior mediastinal masses. They are classified as thymomas, thymic carcinomas, and thymic neuroendocrine neoplasms. Biopsy diagnosis is not common, and most tumors are surgically resected. Biopsy, including cytology, is indicated when a non-surgical entity is suspected or in cases of locally advanced disease. Smears of thymomas consist of round or spindle epithelial cells admixed with varying amounts of lymphocytes depending on the type of thymoma. Smears of thymic carcinoma and thymic neuroendocrine neoplasms are often indistinguishable from corresponding tumor types from other organs. Accurate cytological diagnosis can be difficult due to the histological diversity of thymomas, as well as the morphological features that certain thymic tumors share with similar tumors from other organs. However, fine needle aspiration (FNA) of anterior mediastinal masses can provide clinically actionable information and can be used to determine whether lesions require surgical, systemic, or local noninvasive treatments. Ancillary studies, namely, immunocytochemical stains, flow cytometry, and radiology, are important tools in the evaluation of thymic aspirates. This review discusses the utility and limitations of thymic FNAs and illustrates the diagnostic features and pitfalls of these specimens.

An unusual presentation of thymoma: dysgeusia, ulcerative colitis, keratoconjunctivitis sicca, autoimmune retinopathy and myasthenia gravis

A 41-year-old female presented with dysgeusia, dry eyes, nyctalopia with progressive visual field constriction (due to autoimmune retinopathy) and gastrointestinal symptoms (due to ulcerative colitis). She was subsequently admitted to intensive care with a myasthenic crisis, and CT of the thorax demonstrated a thymoma.Following thymectomy and adjuvant radiotherapy, she has remained in complete remission from her ulcerative colitis and myasthenia gravis, her retinopathy has stabilised and there has been no thymoma recurrence over a 10-year postoperative period. There was a brief relapse of her dysgeusia (causing weight loss) and dry eye symptoms 3 years after her surgery, which resolved 8 months later. While the association of thymomas with paraneoplastic syndromes (PNS) is well established, it is unusual to present with multiple PNS, and some of these have only been documented in sparse case reports to date. Thymectomy played a crucial role in improvement and stabilisation of her PNS.

Thymic tumours: a single center surgical experience and literature review on the current diagnosis and management of thymic malignancies

OBJECTIVE

This study aimed to provide an extensive overview of clinical and pathological findings along with various therapeutic options analyzing in addiction, retrospectively, the surgical outcomes of a single center cohort.

BACKGROUND

Thymic neoplasms are rare thoracic tumors which commonly are located in the anterior mediastinum and are associated with a wide spectrum of clinical presentations. They may run an indolent course or could present a very aggressive biologic progression with infiltration of mediastinal structures and presence of distant metastases. The pathogenesis of these tumors is so far not completely clear. Several treatment modalities in a multidisciplinary setting have to be considered in order to provide the best treatment for patients affected by thymic tumors.

METHODS

We conducted a retrospective cohort analysis of all patients who underwent surgery due to thymic tumor in a university hospital located in Switzerland (Bern University Hospital) and then we performed a narrative review of the English literature using PubMed, Embase, Cochrane Database of Systematic Reviews and Scopus.

CONCLUSIONS

Minimally invasive techniques play an important role in the treatment of thymic tumors. A careful patients selection in a multidisciplinary setting is mandatory in order to offer the best treatment for patients affected by thymic tumors.

Heterogeneity in myasthenia gravis: considerations for disease management

Introduction: Myasthenia gravis is a rare disease of the neuromuscular junction and a prototype of B cell-driven immunopathology. Pathogenic antibodies target post-synaptic transmembrane proteins, most commonly the nicotinic acetylcholine receptor and the muscle-specific tyrosine kinase, inducing end-plate alterations and neuromuscular transmission impairment. Several clinical subtypes are distinct on the basis of associated antibodies, age at symptom onset, thymus pathology, genetic factors, and weakness distribution. These subtypes have distinct pathogenesis that can account for different responses to treatment. Conventional therapy is based on the use of symptomatic agents, steroids, immunosuppressants and thymectomy. Of late, biologics have emerged as effective therapeutic options.Areas covered: In this review, we will discuss the management of myasthenia gravis in relation to its phenotypic and biological heterogeneity, in the light of recent advances in the disease immunopathology, new diagnostic tools, and results of clinical trialsExpert opinion: Clinical management is shaped on serological subtype, and patient age at onset, lifestyle and comorbidities, balancing therapeutic needs and safety. Although reliable biomarkers predictive of clinical and biologic outcome are still lacking, recent developments promise a more effective and safe treatment. Disease subtyping according to serological testing and immunopathology is crucial to the appropriateness of clinical management.

Molecular pathology of thymomas: implications for diagnosis and therapy

Thymomas exhibit a unique genomic landscape, comprising the lowest on average total mutational burden among adult human cancers; a unique point mutation in the GTF2I gene in WHO type A and AB thymomas (and rarely others); almost unique KMT2A-MAML2 translocations in rare WHO type B2 and B3 thymomas; a unique YAP1-MAML2 translocation in almost all metaplastic thymomas; and unique miRNA profiles in relation to GTF2I mutational status and WHO histotypes. While most thymomas can be diagnosed solely on the basis of morphological features, mutational analyses can solve challenging differential diagnostic problems. No molecular biomarkers have been identified that predict the response of unresectable thymomas to chemotherapy or agents with known molecular targets. Despite the common and strong expression of PDL1 in thymomas, immune checkpoint inhibitors are rarely applicable due to the poor predictability of common, life-threatening autoimmune side effects that are related to the unrivaled propensity of thymomas towards autoimmunity.