Paraneoplastic Autoimmune Disorders Research Articles

What Have We Learned from Molecularly Informed Clinical Trials on Thymomas and Thymic Carcinomas-Current Status and Future Directions?

Thymic epithelial tumors (TETs), which include thymomas and thymic carcinomas, are a rare, heterogeneous group of malignancies that originate from the thymus gland. As an important organ of immune cell development, thymic tumors, particularly thymomas, are often associated with paraneoplastic autoimmune disorders. The advances in targeted therapies for both solid and hematologic malignancies have resulted in improved patient outcomes, including better and more durable efficacy and improved toxicity. Targeted therapies have also been investigated in the treatment of TETs, though the results have largely been modest. These have included somatostatin-receptor-targeting therapies, KIT- and EGFR-directed tyrosine kinase inhibitors, epigenetic modulators, anti-angiogenesis agents, and agents targeting the cell proliferation and survival pathways and cell cycle regulators. Numerous investigated treatments have failed or underperformed due to a lack of a strong biomarker of efficacy. Ongoing trials are attempting to expand on previous experiences, including the exploration of effective drugs in early-stage disease. Novel combination therapy strategies are also undergoing evaluation, with the goal of augmenting efficacy and understanding the toxicity while expanding the biomarkers of efficacy and safety. With advances in technology to improve target identification and drug delivery, old targets may become new opportunities, and the subsequently developed drugs may find their place in the treatment of thymic tumors.

Understanding the landscape of immunotherapy in thymic epithelial tumors.

Thymic epithelial tumors (TETs) are a rare group of malignancies arising from the thymus. Surgery remains the foundation of treatment for patients with early-stage disease. Limited treatment options are available for the treatment of unresectable, metastatic, or recurrent TETs and are associated with modest clinical efficacy. The emergence of immunotherapies in the treatment of solid tumors has generated significant interest in understanding their role in TET treatment. However, the high rates of comorbid paraneoplastic autoimmune disorders, particularly in thymoma, have tempered expectations regarding the role of immune-based therapies. Clinical studies of immune checkpoint blockade (ICB) in thymoma and thymic carcinoma have revealed higher frequencies of immune-related adverse events (IRAEs) and limited efficacy. Despite these setbacks, the growing understanding of the thymic tumor microenvironment and systemic immune system has advanced the understanding of these diseases and provided opportunities for novel immunotherapy modalities. Ongoing studies are evaluating numerous immune-based treatments in TETs with the goal of improving clinical efficacy and mitigating IRAE risk. This review will provide insight into the current understanding of the thymic immune microenvironment, outcomes of previous ICB studies, and review treatments currently being explored for the management of TET.

The role of [18F]FDG PET/CT in paraneoplastic autoimmune disorders: an umbrella review.

Paraneoplastic autoimmune disorders (PAD) are a group of autoimmune diseases associated with neoplasms. Several evidence-based articles (systematic reviews and meta-analyses) have reported data about the role of positron emission tomography (PET) and related hybrid modalities (e.g., PET/CT) using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in patients with PAD. We performed an umbrella review of published systematic reviews and meta-analyses in this setting to provide an evidence-based summary and suggestions for further studies. Several databases were searched to find systematic reviews and meta-analysis on [18F]FDG PET/CT in PAD. Evidence-based data support the use of [18F]FDG PET/CT in patients with suspected PAD for investigating an underlying malignancy even if it is still unclear whether [18F]FDG PET/CT should be performed after negative/inconclusive conventional imaging or as part of the initial workup of PAD.

Immunotherapy for Management of Thymic Epithelial Tumors: A Double-Edged Sword.

Simple SummaryImmunotherapy has a rapidly expanding role for the treatment of several cancers due to durable clinical activity and favorable tolerability. However, the unique biology of thymic epithelial tumors (TETs) increases the risk of immune-mediated toxicity. In this paper we review the biology of thymic cancers and its impact on the potential benefits and risks of immunotherapy. We describe the results of completed clinical trials of immune checkpoint inhibitors for advanced TETs and provide an overview of potential biomarkers of response or toxicity of immunotherapy that might influence future development of immunotherapeutic modalities for the treatment of advanced thymoma and thymic carcinoma.Thymic epithelial tumors (TETs) are rare thoracic cancers that are broadly classified as thymomas and thymic carcinomas. Surgery is the cornerstone of management for early-stage disease. There are a limited number of effective treatment options for patients with advanced or recurrent disease. The occurrence of paraneoplastic autoimmune disorders in patients with TETs, especially thymomas, creates significant challenges for the development of immunotherapy, including immune checkpoint inhibitors, as a feasible treatment option. In addition, patients with TETs are at increased risk for the development of immune-mediated toxicity with a predilection for musculoskeletal and neuromuscular adverse events upon treatment with immunotherapy. The identification of biomarkers of response and toxicity is expected to play a key role in harnessing the benefits of immunotherapy for patients with TETs. In this paper we review the biology of TETs and the potential effects on the tolerability of immunotherapy. The results of clinical trials of immune checkpoint inhibitors for the treatment of advanced TETs are described to understand the potential risks and benefits of immunotherapy. We also provide an overview of future avenues for treatment with novel immunotherapeutic modalities and opportunities to develop biomarkers to improve the safety and tolerability of immunomodulatory treatments in patients with TETs.

Isaacs\u2019 syndrome as the initial presentation of malignant thymoma and associated with double-positive voltage-gated potassium channel complex antibodies, a case report

BackgroundIsaacs’ syndrome is a peripheral nerve hyperexcitability (PNH) syndrome due to peripheral motor nerve instability. Acquired Isaacs’ syndrome is recognized as a paraneoplastic autoimmune disease with possible pathogenic voltage-gated potassium channel (VGKC) complex antibodies. However, the longitudinal correlation between clinical symptoms, VGKC antibodies level, and drug response is still unclear.Case presentationA 45-year-old man had progressive four limbs soreness, muscle twitching, cramps, and pain 4 months before admission. Electromyography (EMG) studies showed myokymic discharges, neuromyotonia, and an incremental response in the high-rate (50 Hz) repetitive nerve stimulation (RNS) test. Isaacs’ syndrome was diagnosed based on clinical presentations and EMG reports. Serum studies showed positive VGKC complex antibodies, including leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) antibodies. The acetylcholine receptor antibody was negative. Whole-body computed tomography (CT) and positron emission tomography revealed a mediastinal tumor with the great vessels encasement, right pleura, and diaphragm seeding. Biopsy confirmed a World Health Organization type B2 thymoma, with Masaoka stage IVa. His symptoms gradually improved and both LGI1 and CASPR2 antibodies titer became undetectable after concurrent chemoradiotherapy (CCRT) and high dose steroid treatment. However, his Isaacs’ syndrome recurred after the steroid was reduced 5 months later. Follow-up chest CT showed probable thymoma progression. LGI1 antibody turned positive again while CASPR2 antibody remained undetectable.ConclusionsOur patient demonstrates that Isaacs’ syndrome could be the initial and only neuromuscular manifestation of malignant thymoma. His Isaacs’ syndrome is correlated well with the LGI1 antibody level. With an unresectable thymoma, long-term immunosuppressant therapy may be necessary for the management of Isaacs’ syndrome in addition to CCRT for thymoma.

Tolerability of Coronavirus Disease 2019 Vaccines, BNT162b2 and mRNA-1273, in Patients With Thymic Epithelial Tumors

IntroductionDefects in immunologic self-tolerance result in an increased risk for development of paraneoplastic autoimmune diseases (ADs) and immune-mediated toxicity in response to immune stimulation in individuals with thymic epithelial tumors (TETs). We conducted a survey to evaluate the tolerability of coronavirus disease 2019 (COVID-19) mRNA vaccines in patients with TETs, including individuals with preexisting AD. MethodsAfter reviewing published data on adverse events associated with the BNT162b2 (Pfizer, Inc., and BioNTech) and mRNA-1273 (ModernaTX, Inc.) mRNA vaccines, we designed and administered a questionnaire to participants at the following three time points: after each dose of vaccination and 1 month after the final dose. Questions related to AD and use of immunosuppressive drugs were included. Descriptive statistics were used to analyze data, and results were compared with previously described results related to the BNT162b2 and mRNA-1273 vaccines. ResultsFrom February 26 to June 1, 2021, we administered the survey to 54 participants (median age = 58 y, thymoma = 33, preexisting AD = 19). Common adverse events included injection site pain, fatigue, and headaches. There were no vaccination-related hospitalizations or deaths. Autoimmune flares occurred in three patients (16%) after the first dose and three patients (17%) after the second dose. Most AD flares were mild and self-limited. One patient (2%) was diagnosed with having a new AD after vaccination. ConclusionsTolerability of COVID-19 mRNA vaccines in patients with TETs is comparable to the general population. Most patients with preexisting AD did not experience disease flares, and the development of new AD was rare. Patients with TETs should be encouraged to get vaccinated against COVID-19 owing to the documented benefits of vaccination and manageable risk profile.

Everolimus in the treatment of metastatic thymic epithelial tumors

IntroductionThere is emerging evidence to support the use of mTOR inhibitor everolimus in patients with advanced, relapsed-refractory thymic epithelial tumors (TETs). However, patient selection and identifying predictive biomarkers of response remains a challenge. Here, we describe a single-center experience with everolimus in patients with TETs and provide detailed molecular analysis of their thymic tumors. Materials and MethodsData on all patients with advanced TETs who were prescribed everolimus at Stanford University were retrospectively assessed. Time to treatment failure (TTF) and overall survival (OS) were calculated. STAMP, a 130-gene targeted next generation sequencing (NGS) panel, was performed on each tumor sample. ResultsTwelve patients with thymoma (T) and three with thymic carcinoma (TC) treated with everolimus were included. Patients had been heavily pre-treated with an average of three prior lines of therapy. Three patients discontinued treatment due to adverse events. The average TTF was 14.7 months in T and 2.6 months in TC with median OS of 27.6 months in the entire cohort (NR T and 5.3 months TC). Two patients with paraneoplastic autoimmune diseases had improvement in autoimmunity on everolimus. Pathogenic mutations were observed in 4/15 (27 %) of patients and includedTP53, KEAP1 and CDKN2A. Several variants of unknown significance in key genes responsible for modulating tumor response to mTOR inhibition were also found. ConclusionAs previously reported in a prospective trial, patients with previously treated advanced TETs appear to benefit from everolimus in this single institution cohort. Moreover, there was a manageable toxicity profile and no cases of everolimus-induced pneumonitis. A targeted NGS panel revealed several pathogenic mutations but there was no association between detectable tumor mutations and time to treatment failure in this cohort.

Downregulation of CYLD promotes IFN-γ mediated PD-L1 expression in thymic epithelial tumors

ObjectivesRecent genomic studies suggest the biological significance of the cylindromatosis (CYLD) gene in thymic epithelial tumors (TETs). CYLD is a crucial regulator of immune response, and we previously reported that CYLD mutation is associated with high PD-L1 expression in thymic carcinoma. Therefore, we wanted to explore the role and mechanism of CYLD in regulating PD-L1 expression in TETs. Materials and methodsThe role of CYLD in PD-L1 expression was assessed by knockdown of CYLD in TET cells upon stimulation with interferon gamma (IFN-γ), tumor necrosis factor-α (TNF-α) or polyinosinic-polycytidylic acid (poly I:C). The molecular mechanism was investigated through analysis of downstream molecules in the STAT1/IRF1 pathway. Moreover, the clinical correlation between low CYLD and high PD-L1 expression, and the clinical impact of CYLD expression were evaluated in tissue microarrays of 105 TET cases. ResultsCYLD knockdown significantly enhanced the expression of PD-L1 in presence of IFN-γ stimulation in most TET cell lines. However, this phenomenon was not observed in presence of TNF-α stimulation. CYLD knockdown upregulated IFN-γ mediated activation of the STAT1/IRF1 axis, which in turn induced PD-L1 expression. Interestingly, we found a significant association between low CYLD expression and ≥ 50 % PD-L1 expression (p = 0.001). In addition, the average proportion of tumor cells exhibiting PD-L1 staining was significantly higher in the low CYLD expression group (24.7 %) than in the high CYLD expression group (5.2 %) (p = 0.005). There was no correlation between CYLD expression and the frequency of pre-existing paraneoplastic auto-immune diseases. In advanced stages (III/IV), the low CYLD expressing group had numerically worse survival than the high CYLD group (log-rank p = 0.089). ConclusionsOur findings provide insight into the mechanism of regulation of PD-L1 expression by CYLD in TET cells. Tumors with low CYLD expression could be potential targets for PD-1/PD-L1 inhibitors.

Aetiology and pathogenesis of paraneoplastic autoimmune disorders.

Paraneoplastic autoimmune disorders (PAD) represent a group of autoimmune diseases associated with neoplasms. As a consequence of a remote autoimmunity-mediated effect, PAD are found in multiple organs or tissues, including the skin, blood and nervous system. Compared with non-paraneoplastic autoimmune diseases, PAD have different aetiologies, pathologies, disease symptoms and treatment responses. There are two main origins of autoimmunity in PAD: neoplasm-mediated dysregulated homeostasis in immune cells/organs and in autoantigens. Pathologically, PAD are mediated predominantly by either autoantibodies or autoreactive T-cells. In the past decade, significant progress has been achieved in increasing our understanding of the aetiology and pathology of PAD. In this review article, we aim to provide a comprehensive overview of the recent advances in this field.

Deciphering the biology of thymic epithelial tumors.

Thymic cancers arise from epithelial cells of the thymus and have a predilection for intrathoracic spread. Clinical behavior varies from relatively indolent to highly aggressive with a capacity to metastasize widely and adversely affect survival. Paraneoplastic autoimmune disorders are frequently observed in association with thymoma and have a significant impact on quality of life. Underlying immune deficits associated with thymic epithelial tumors (TETs) increase the risk for development of opportunistic infections and emergence of extrathymic malignancies. Advances in the molecular characterization of thymic tumors have revealed the lowest tumor mutation burden among all adult cancers and the occurrence of distinct molecular subtypes of these diseases. Mutations in general transcription factor IIi (GTF2I) are unique to TETs and are rarely observed in other malignancies. The infrequency of actionable mutations has created obstacles for the development of biologic therapies and has spurred research to uncover druggable genomic targets. Persistence of autoreactive T cells due to altered thymic function increases the risk for development of severe immune-related toxicity and limits opportunities for use of immune-based therapies, especially in patients with thymoma. In this paper we review emerging data on the molecular characterization and immunobiology of thymic tumors and highlight clinical implications of these discoveries.

Paraneoplastic Systemic Sclerosis in a Patient with Metastatic Thymic Carcinoma

Thymic malignancies cause alterations in the immune system. Thymomas are known to be associated with paraneoplastic syndrome and autoimmunity, including myasthenia gravis, systemic lupus erythematosus, inappropriate antidiuretic hormone secretion, pure red cell aplasia, pernicious anemia, pemphigus, and autoimmune thyroid diseases. However, paraneoplastic syndrome has rarely been observed in patients with thymic carcinoma. The management of patients with paraneoplastic autoimmune disease is difficult, and treatment of the underlying malignancy is important. Herein, we present a case of thymic carcinoma who developed systemic sclerosis 3 years after the initial diagnosis during disease progression.

Paraneoplastic autoimmune diseases in patients with thymic malignancies: a favorable, but not independent, prognostic factor

Thymomas and thymic carcinomas are rare epithelial tumors of thymus (TETs) associated with paraneoplastic autoimmune (PN/AI) disorders, including myasthenia gravis (MG), pure red cell aplasia, hypogammaglobulinemia, encephalitis, and acquired neuromyotonia (1,2). Patients affected by these disorders are usually screened for thymoma at diagnosis, and they frequently improve with thymoma treatment (2).

Pembrolizumab in patients with thymic carcinoma: a single-arm, single-centre, phase 2 study

Treatment options are limited for patients with thymic carcinoma. These aggressive tumours are not typically associated with paraneoplastic autoimmune disorders, and strong PD-L1 expression has been reported in thymic epithelial tumours. We aimed to assess the activity of pembrolizumab, a monoclonal antibody that targets PD-1, in patients with advanced thymic carcinoma. We completed a single-arm phase 2 study of pembrolizumab in patients with recurrent thymic carcinoma who had progressed after at least one line of chemotherapy. This was a single-centre study performed at Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA. Key inclusion criteria were an Eastern Cooperative Oncology Group performance status of 0-2, no history of autoimmune disease or other malignancy requiring treatment or laboratory abnormality, and adequate organ function. Patients received 200 mg of pembrolizumab every 3 weeks for up to 2 years. The primary objective of the study was the proportion of patients who had achieved a response assessed with Response Evaluation Criteria in Solid Tumors version 1.1. Analysis was per protocol, in all eligible patients. The study is registered with ClinicalTrials.gov, number NCT02364076, and is closed to accrual; we report the final analysis. 41 patients were enrolled from March 12, 2015, to Dec 16, 2016, of whom 40 were eligible and evaluable and one was excluded because of elevated liver enzymes at screening. The median follow-up was 20 months (IQR 14-26). The proportion of patients who achieved a response was 22·5% (95% CI 10·8-38·5); one (3%) patient achieved a complete response, eight (20%) patients achieved partial responses, and 21 (53%) patients achieved stable disease. The most common grade 3 or 4 adverse events were increased aspartate aminotransferase and alanine aminotransferase (five [13%] patients each). Six (15%) patients developed severe autoimmune toxicity, including two (5%) patients with myocarditis. There were 17 deaths at the time of analysis, but no deaths due to toxicity. Pembrolizumab is a promising treatment option in patients with thymic carcinoma. Because severe autoimmune disorders are more frequent in thymic carcinoma than in other tumour types, careful monitoring is essential. Merck & Co.

A case series of malignancies: mimics of Rheumatological disorders

Background: Malignancy and Autoimmunity interplay is full of complexities. We here, describe few cases of malignancies presented as mimics of autoimmune disorders. A case of acute myeloid leukaemia had leukocytoclastic vasculitis, positive ANA, positive SS-A, and few clinical features of autoimmune disease and it mimicked UCTD. Second case of signet ring cell type of adenocarcinoma of G.I tract mimicked CTD as it had ANA positivity and ILD. Third case was epitheloid sarcoma which mimicked pyomyositis while fourth case was multiple myeloma presented with leukocytoclastic vasculitis, positive ANA, malar rash and active urinary sediments and it had mimicry of SLE. Malignancies can present as autoimmune diseases or they can mimic flare of Rheumatological diseases. Cancer can present as vasculitides, CTDs, myositis or arthritides. Sometimes, it is difficult to ascertain whether autoimmune disorders have caused cancers or malignancies have caused autoimmune disturbances. ANA can be positive in upto 27% cancer patients. There is clearly increased risk of cancers amongst patients of autoimmune diseases compared to general population. Malignancies including metastasis can also present with true paraneoplastic autoimmune disorders. They usually present later in the course of the disease but sometimes surprise internists with sudden appearance in early course of the disease. High index of suspicion is required to detect malignancies in autoimmune diseases as both have invariably similar presentations. PET scan and tissue diagnosis are amongst the major investigations to treat patients with spectrum of malignancy and autoimmunity.

Paraneoplastic autoimmune movement disorders

Purpose of reviewTo provide an overview of paraneoplastic autoimmune disorders presenting with various movement disorders. Recent findingsThe spectrum of paraneoplastic autoimmune disorders has been expanding with the discovery of new antibodies against cell surface and intracellular antigens. Many of these paraneoplastic autoimmune disorders manifest as a form of movement disorder. With the discovery of new neuronal antibodies, an increasing number of idiopathic or neurodegenerative movement disorders are now being reclassified as immune-mediated movement disorders. These include anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis which may present with orolingual facial dyskinesia and stereotyped movements, CRMP-5 IgG presenting with chorea, anti-Yo paraneoplastic cerebellar degeneration presenting with ataxia, anti-VGKC complex (Caspr2 antibodies) neuromyotonia, opsoclonus-myoclonus-ataxia syndrome, and muscle rigidity and episodic spasms (amphiphysin, glutamic acid decarboxylase, glycine receptor, GABA(A)-receptor associated protein antibodies) in stiff-person syndrome. SummaryMovement disorders may be a presentation for paraneoplastic autoimmune disorders. Recognition of these disorders and their common phenomenology is important because it may lead to the discovery of an occult malignancy.

Morvan Syndrome Secondary to Thymic Carcinoma in a Patient with Systemic Lupus Erythematosus.

Morvan syndrome (MoS) is a rare paraneoplastic autoimmune disorder characterized by peripheral nerve hyperexcitability, autonomic dysfunction, and sleep disorders. Systemic lupus erythmatosus (SLE) cooccurs in 6–10% of patients with thymoma. It may occur before, concurrently with, or after thymoma diagnosis. This paper reports the first case of cooccurrence of SLE, thymic carcinoma, and MoS. The cooccurrence of SLE, thymoma, and MoS delineates the generalized autoimmunity process. Symptoms of both MoS and SLE abated upon tumor resection.

Association between autoimmune disease and cutaneous melanoma with regard to melanoma prognosis.

An association between autoimmune disease and malignant melanoma (MM) has often been reported in the literature as a positive prognostic factor for MM. Consequently, we evaluated the influence of different autoimmune diseases on the prognosis of MM. To evaluate the prognosis of patients with MM who also had an autoimmune disorder, whether tumour-associated, paraneoplastic or drug-induced. Autoimmune diseases were classified and analysed as tumour-associated, paraneoplastic or drug-induced. Patients were enrolled according to their clinicopathological features and matched with control groups. Kaplan-Meier analysis was used to estimate disease-free survival (DFS) and overall survival (OS), and log-rank test was used to evaluate differences between the survival curves. In total, 49 patients with MM and tumour-associated autoimmune disease were included in our analysis. No case of paraneoplastic autoimmune disease was detected. The survival analyses showed a range of results, from a worsening of DFS and OS to a lack of any difference. In a second analysis, we separately analysed patients who developed autoimmune disorders after starting adjuvant therapy with interferon-α; we did not find significant differences between these patients and the untreated patients. Autoimmune disease, whether tumour-associated or drug-induced, was not associated with better prognosis in patients with MM. The results suggest that the reported relationship between autoimmunity and MM may be a result of individual variation in sensitivity to the autoimmune disease, the tumour or the treatments.

Paraneoplastic inflammation in myelodysplastic syndrome or bone marrow failure: case series with focus on 5‐azacytidine and literature review

Myelodysplastic syndrome (MDS) comprises a heterogeneous group of clonal disorders of haematopoietic stem cells, characterised by dysplastic haematopoiesis and dysregulated apoptosis resulting in various degrees of cytopenia, whereas canonical cytologic, cytogenetic and histopathologic findings guiding the diagnosis MDS are widely accepted, the MDS-phenotype can be masked by coexisting/paraneoplastic immunologic disease. Autoimmune disorders have an estimated incidence of 10% among patients suffering from MDS and are causally related to increased morbidity and mortality, younger age at diagnosis and more complex genetics. Conversely, systemic inflammatory disorders may be an early manifestation of MDS, show good response to immunosuppressive therapy and frequently disappear during the course of specific haematologic therapy. Monocentric report on clinical phenotypes found in MDS or bone marrow failure with paraneoplastic inflammatory disease. Clinical case reports and systematic review about MDS pathophysiology and treatment. We report eight patients diagnosed with MDS or bone marrow failure, who presented with paraneoplastic autoimmune diseases. Six of eight patients were treated with the hypomethylating agent 5-azacytidine, three of which achieved meaningful response with regard to inflammation control and haematologic recovery. As paraneoplastic syndromes are often mistakenly diagnosed as idiopathic autoimmune disorders, we propose that coexistence of an underlying myelodysplastic syndrome should be considered early in the diagnostic work up. 5-Azacytidine is effective in controlling paraneoplastic inflammation.

Diminished regulatory T cells in cutaneous lesions of thymoma-associated multi-organ autoimmunity: a newly described paraneoplastic autoimmune disorder with fatal clinical course

Thymoma-associated multi-organ autoimmunity is a rare, autoimmune disease that causes colitis, liver dysfunction and cutaneous graft-versus-host (GVH)-like skin damage. This paraneoplastic autoimmune disorder may be due to inadequate T cell selection in the tumour environment of the thymus. Although sporadic case reports have revealed its clinical features, little is known about its pathological mechanism. By comparing the skin-infiltrating T cell subsets with those of GVH disease (GVHD) and other inflammatory skin diseases, we sought to elucidate the pathological mechanism of thymoma-associated multi-organ autoimmunity. Histopathological and immunohistochemical analysis of skin biopsies was performed for three patients with thymoma-associated multi-organ autoimmunity. Histopathological findings of thymoma-associated multi-organ autoimmunity were indistinguishable from those of patients with acute GVHD, although the aetiologies of these diseases are completely different. The frequency of regulatory T cells (T(regs)) is reduced in cutaneous lesions and CD8+ cytotoxic T lymphocytes that massively infiltrate into the epidermis of patients with thymoma-associated multi-organ autoimmunity. Additionally, the ratio of T helper type 17 (Th17) cells to CD4+ cells in patients with thymoma-associated multi-organ autoimmunity and acute GVHD was higher than that in healthy controls, but similar to that in psoriasis vulgaris patients. Similarity of the skin-infiltrating T cell subsets with those of acute GVHD suggested that skin damage in patients with thymoma-associated multi-organ autoimmunity might be induced by self-reactive cytotoxic T lymphocytes under the diminished suppressive capacity of T(regs).

Multiple paraneoplastic syndromes: Myasthenia gravis, vitiligo, alopecia areata, and oral lichen planus associated with thymoma

Thymomas are associated with paraneoplastic autoimmune diseases at a high frequency. It is rare that four paraneoplastic autoimmune disorders co-occur in a single patient. We describe a thymoma patient with diagnoses of myasthenia gravis, vitiligo, alopecia areata, and oral lichen planus associated with a thymoma. After thymectomy, the weakness, vitiligo, alopecia and mucocutaneous lesions were improving progressively, possibly implicating the thymoma in initiating these autoimmune conditions. We believe that this is the first report of this particular combination of multiple paraneoplastic syndromes associated with thymoma.