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Background and Objectives: To investigate intrathymic B lymphopoiesis in patients with myasthenia gravis (MG) and explore thymus pathology associated with clinical impact., Methods: Thymic lymphocytes from 15 young patients without MG, 22 adult patients without MG, 14 patients with MG without thymoma, and 11 patients with MG with thymoma were subjected to flow cytometry analysis of T follicular helper (Tfh), naive B, memory B, plasmablasts, CD19 + B220 high thymic B cells, B-cell activating factor receptor, and C-X-C chemokine receptor 5 (CXCR5). Peripheral blood mononuclear cells of 16 healthy subjects and 21 untreated patients with MG were also analyzed. Immunologic values were compared, and correlations between relevant values and clinical parameters were evaluated., Results: The frequencies of circulating and intrathymic plasmablasts were significantly higher in patients with MG than controls. On the other hand, the frequency of CD19 + B220 high thymic B cells was not increased in MG thymus. We observed a significant increase in CXCR5 expression on plasmablasts in MG thymus and an increased frequency of intrathymic plasmablasts that was correlated with preoperative disease activity. The frequency of intrathymic Tfh cells was significantly lower in patients who received immunosuppressive (IS) therapy than those without IS therapy. However, there was no significant difference in the frequency of intrathymic plasmablasts irrespective of IS therapy., Discussion: Our findings confirmed a correlation between increased frequency of intrathymic plasmablasts and disease activity before thymectomy. We postulate that activated intrathymic plasmablasts endow pathogenic capacity in MG., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Thymic adenocarcinoma is an extremely rare neoplasm, and little is known about its pathogenesis and clinical characteristics. A 52-year-old man presented to our clinic with severe dyspnea. At initial presentation, massive carcinomatous pleuritis and pericarditis were observed, and a lobulated mass in the anterior mediastinum was found on computed tomography. Cytological examination revealed adenocarcinoma accompanied by signet ring cells; however, his tumor showed aggressive growth without any possibility of treatment, and he died as a result of cancer progression within one month of admission. An autopsy confirmed thymic adenocarcinoma showing various histological features including mucinous, signet ring cell-like, and trabecular features. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) (AE1/AE3) but negative for TTF-1. In addition, some tumor cells were positive for CD5 and KIT. Further examination revealed that tumor cells of the nonmucinous type were positive for CK7, and negative for CK20 and caudal-type homeobox 2 (CDX2). The tumor cells with mucinous and signet ring-like features were positive for CK20 and CDX2 and negative for CK7, indicating enteric differentiation. In particular, tumor cells with signet ring cell-like features indicated widespread lymphangitic carcinomatosis and pulmonary tumor thrombotic microangiopathy (PTTM). The presence of signet ring cell-like features with enteric differentiation is suggestive of a fulminant clinical course due to widespread lymphangiosis carcinomatosa and PTTM in patients with thymic adenocarcinoma. KEY POINTS: Thymic adenocarcinoma is an extremely rare neoplasm. Histological features of thymic adenocarcinoma include mucinous, signet ring cell-like, and trabecular features. Tumor cells with signet ring cell-like features indicate widespread lymphangitic carcinomatosis and pulmonary tumor thrombotic microangiopathy. The presence of signet ring cell-like features with enteric differentiation is associated with a fulminant clinical course., (© 2020 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Purpose: To report a patient with thymoma-associated retinopathy presenting as having a good visual prognosis., Methods: Case report and literature review., Case Report: A 42-year-old female patient was referred to our hospital for complaints of sudden visual-field defects bilaterally. Decimal corrected visual acuity (VA) was 1.5 and 1.2 in the right (RE) and left eyes (LE), respectively. Fundus autofluorescence revealed hyper-autofluorescence from the posterior pole to mid-peripheral retina in both eyes. Full-field electroretinography (ERG) amplitudes were reduced to 20-50% and 30-50% of our controls for the scotopic and photopic conditions, respectively. A systemic examination revealed the presence of thymoma, and the patient underwent thymectomy and immunosuppression therapies. Immunohistochemical analysis using the patient's serum showed immunolabeling on the photoreceptor inner segment and outer plexiform layer in the monkey retina. Two years later, VA remained at 1.5 and 1.2 in RE and LE. ERG amplitudes improved to 30-60% of the controls for the scotopic conditions. However, photopic ERG showed no remarkable change., Conclusions: To our knowledge, improvement of reduced rod-mediated ERG responses has not been described in seven previously reported patients with thymoma-associated retinopathy. The good visual prognosis of our patient may be associated with well-timed intervention.

Pure red cell aplasia (PRCA) is a rare disease characterised by anaemia and low reticulocyte count, caused by absence of erythropoiesis in the bone marrow. This report describes a case of a ring-calcified thymoma that led to the development of PRCA. Moreover, we provide an overview on the classification of thymoma and the pathophysiology and treatment of PRCA.

Objectives: The management of patients with locally advanced thymic malignancies remains controversial. Differing combinations of surgical resection, chemotherapy and radiation are used in the management of initial and relapsed disease. Treatment-related toxicities and quality of life could inform therapeutic options. This study describes health utility scores (HUS) in survivors with locally advanced thymic malignancies and investigates the impact of multimodality regimens on HUS., Methods: In a cross-sectional study (2014-2017), patients with Masaoka Stage II-IVa thymic malignancies completed various self-reported questionnaires, including EuroQol-5-Dimensions with visual analogue scale (VAS), Eastern Cooperative Oncology Group (ECOG) and Edmonton Symptom Assessment Scale tools. Trimodality versus uni- or bimodality regimens and aggressive versus non-aggressive management of recurrent disease were compared using regression analyses., Results: Of the 72 patients, 43 (60%) were male with a median age of 58 years, 65 (90%) had thymoma while 7 (10%) had thymic carcinomas; and median time since diagnosis was 50.5 months (range: 3-266). Median HUS and VAS did not differ between groups (trimodality n = 24 vs uni- or bimodality n = 48: HUS = 0.77 vs 0.80, P = 0.29; VAS = 80 vs 75, P = 0.79, respectively). The distributions of patient-reported ECOG were also similar (P = 0.86). Edmonton Symptom Assessment Scale scores for every assessed symptom were similar for different modalities of therapy. Median scores on these tools were also similar regardless of recurrence status or management of relapsed disease (aggressive versus non-aggressive)., Conclusion: Survivors with Stage II-IVa thymic malignancies report favourable HUS, VAS and self-reported ECOG with minimal symptom burden. These outcomes may be independent of number and type of initial treatment modalities or management of recurrence.

Purpose: To report on the implementation, validation and results of the first two proton therapy PBS treatments of limited amplitudes moving targets performed at our center., Methods and Materials: A real time optical tracking system was used to monitor the patient surface during the CT scan and treatment. This system is also able to trigger the beam during the treatment. A 4DCT (10 phases) and a Free-Breathing CT (FBCT) were used for the planning. The physician used the 4DCT for ITV delineation, while planning was performed on the FBCT. The approved plan was evaluated in two ways:The largest breathing amplitude recorded during 4DCT scan was used as gating safety threshold during treatment delivery. This planning and treatment workflow was then applied for two patients affected by thoracic thymoma., Results: The dosimetric evaluation of the plan showed no interplay effect. The second patient showed an overdosage to the coronary and Left Anterior Descending area in the worst case scenario but it was below the constraints. Duty Cycle together with number of beam interruptions gave information about the patient compliance to the treatment: the first patient breath is stable and within thresholds, whilst the second patient had more variations, causing multiple beam interruptions., Conclusion: We defined and used for two patients a protocol for the treatment of small amplitude moving targets. The planning and delivery of the treatments gave very good results in terms of coverage, OARs sparing, 4D dose evaluation of the plan and interplay effect assessment., (Copyright © 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Routine imaging for mediastinal malignancies includes chest X-ray, CT or MRI. T1 and T2 mapping are novel MRI techniques which may have a role in expanding the assessment of internal tumour characteristics. This case report details two middle-aged women who had similar clinical presentations of mediastinal masses of comparable size and appearance when assessed with routine imaging. T1 and T2 maps were acquired on MRI to investigate whether these tumours could be further differentiated prior to surgery. T1 and T2 mapping supported suspicion for which tumour components were solid and cystic, as subsequently confirmed histologically. Furthermore, comparison between the two tumours showed native T1 values differed within the solid components by 37%, correlating to differences in proteinaceous material within the tumour types. This radiological-pathological correlation provides evidence that T1 and T2 mapping has clinical utility in the assessment and differentiation of mediastinal masses., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Rationale: Sclerosing thymoma is an extremely rare mediastinal neoplasm; it was recognized for the first time in 1994 and to date only 15 cases have been reported., Patient Concerns: The present study report a case of a 65-year-old man who was incidentally found to have an anterior mediastinal nodule, without clinical symptoms including fever, chest pain, and myasthenia gravis., Diagnoses: The chest computed tomography (CT) revealed the nodule was 4.9 × 4.2 × 3.0 cm in size. And the microscopic and immunohistochemical findings indicated that the final diagnosis was sclerosing thymoma., Interventions: The anterior mediastinal nodule was completely removed., Outcomes: No evidence of recurrence or complication was found in the second year after surgery., Lessons: The biologic behavior of the rare sclerosing thymoma is still largely mysterious; it is utmost importance to classify the sclerosing thymoma from other mediastinal tumors. Its prognosis is favorable and thymectomy is currently the mainstay of treatment.

Tumours show an increased interstitial fluid pressure, which correlates with various pathophysiological features. Moreover, interstitial fluid pressure is a prognostic factor for cervical and lung cancer. However, there have been no reports on the usefulness of measuring interstitial fluid pressure in thymic epithelial tumours. Therefore, this study aimed to examine the relationship between interstitial fluid pressure and the clinicopathological characteristics of thymic epithelial tumours. Interstitial fluid pressure was prospectively measured at the centre of the tumour using a 1-Fr Mikro-Tip sensor catheter in 44 patients with thymic epithelial tumours, 40 with thymomas and 4 with thymic carcinomas. Data from these 44 patients were analysed for correlations between interstitial fluid pressure and clinicopathological and demographic factors including sex, age, tumour size, World Health Organization histological subtypes, myasthenia gravis, capsular invasion, mediastinal pleura invasion, lung invasion, pericardium invasion, dissemination, Masaoka-Koga stage, maximal standardized uptake value and recurrence-free survival (RFS). The mean interstitial fluid pressure was 11.3 mmHg; interstitial fluid pressure was significantly correlated with maximal standardized uptake value, lung invasion, dissemination and Masaoka-Koga stage. Low interstitial fluid pressure (≤14 mmHg) showed a tendency for better RFS compared with high interstitial pressure (P = 0.053). Lung invasion, dissemination and Masaoka-Koga stage were correlated with RFS in univariable analysis; lung invasion was selected as an independent prognostic factor in multivariable analysis. On the basis of these results, interstitial fluid pressure of thymic epithelial tumours has been shown to correlate with their clinicopathological features., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Neuroendocrine tumors are a large group of tumors with a wide spectrum of behavior, affecting mainly the digestive system and the lung. The thymus is very rarely affected., Case Presentation: A 28-year-old Arab woman presented with chronic chest pain and dyspnea. A computed tomography scan showed a huge anterior mediastinal mass invading neighboring structures. A mediastinotomy was performed with biopsies of the mass. Pathological findings were consistent with a thymic large cell neuroendocrine carcinoma., Conclusions: The occurrence of a large cell neuroendocrine carcinoma in the thymus, especially in young people, is extremely rare. In this current report, we discuss the clinicopathological issues of this rare tumor according to recent literature data.

Thymic neuroendocrine neoplasms are rare tumours, but their management can often be highly problematic. While previously assumed to be essentially variants of bronchopulmonary (lung) carcinoids, they are generally more aggressive and more difficult to treat. Some 25% are associated with multiple endocrine neoplasia-1, while a higher proportion are associated with the ectopic ACTH syndrome, and occasionally both. We discuss the classification of these tumours, their biology as far as is known, and their clinical, biochemical and imaging features. We also review possible management options and suggest stratagems to optimise their treatment, which even today is far from optimal., (© 2017 S. Karger AG, Basel.)

A 48-year-old woman was admitted to our hospital to undergo evaluation for fatigue, severe weight loss, and nephrotic range proteinuria. Light microscopy of a renal biopsy specimen revealed class III (A) lupus nephritis, while immunofluorescence and electron microscopy only showed sparse immune deposits with findings that were not typical of lupus nephritis. Computed tomography revealed a mass in the anterior mediastinum, which was resected. The examination of the surgical specimen revealed type A noninvasive thymoma. In combination with thymomectomy, postoperative steroid therapy achieved the prompt remission of lupus nephritis. In this patient, thymoma-related autoimmunity may have contributed to the exacerbation of lupus nephritis.

Chromosomal instability is a hallmark of cancer, but mitotic regulators are rarely mutated in tumors. Mutations in the condensin complexes, which restructure chromosomes to facilitate segregation during mitosis, are significantly enriched in cancer genomes, but experimental evidence implicating condensin dysfunction in tumorigenesis is lacking. We report that mice inheriting missense mutations in a condensin II subunit (Caph2 nes ) develop T-cell lymphoma. Before tumors develop, we found that the same Caph2 mutation impairs ploidy maintenance to a different extent in different hematopoietic cell types, with ploidy most severely perturbed at the CD4 + CD8 + T-cell stage from which tumors initiate. Premalignant CD4 + CD8 + T cells show persistent catenations during chromosome segregation, triggering DNA damage in diploid daughter cells and elevated ploidy. Genome sequencing revealed that Caph2 single-mutant tumors are near diploid but carry deletions spanning tumor suppressor genes, whereas P53 inactivation allowed Caph2 mutant cells with whole-chromosome gains and structural rearrangements to form highly aggressive disease. Together, our data challenge the view that mitotic chromosome formation is an invariant process during development and provide evidence that defective mitotic chromosome structure can promote tumorigenesis., (© 2016 Woodward et al.; Published by Cold Spring Harbor Laboratory Press.)

The human thymus supports the production of self-tolerant T cells with competent and regulatory functions. Various cellular components of the thymic microenvironment such as thymic epithelial cells (TEC) and dendritic cells play essential roles in thymic T cell differentiation. The multiple cellular events occurring during thymic T cell and TEC differentiation involve proteins regulating cell cycle and apoptosis. Dysregulation of the cell cycle and apoptosis networks is involved in the pathogenesis of thymic epithelial tumors (TET) which are divided into two broad categories, thymomas and thymic carcinomas. The present review focuses on the usefulness of the analysis of the expression patterns of major cell cycle and apoptosis regulators in order to gain insight in the histophysiology of thymus and the histopathology, the clinical behavior and the biology of TET.

A 50-year-old man presented to our hospital in 1995. Invasive thymoma was diagnosed and extended thymectomy and left upper lobe partial resection were performed. In 2013, he complained of dyspnea. Chest computed tomography showed postoperative recurrence of invasive thymoma. Several chemotherapies were administered. Severe anemia and an increase in the total bilirubin level were observed with chemotherapies. In additional, an examination showed that the direct Coombs test was positive. Cold agglutinin was also high. We herein experienced a rare case of postoperative recurrence of invasive thymoma with cold agglutinin disease and autoimmune hemolytic anemia.

Purpose: The aim of this study was to investigate the value of morphologic, functional, and metabolic biomarkers acquired concurrently at PET/MRI in patients with thymic epithelial tumors., Patients and Methods: During 1 year, 9 patients with suspected thymic epithelial tumors at contrast-enhanced chest CT were prospectively enrolled and underwent preoperative 18F-FDG PET/MRI. Two chest radiologists prospectively reviewed the CT and MRI scans of PET/MRI in consensus, and 2 nuclear physicians reviewed the PET images. Visual assessment of the tumor morphology, functional biomarkers such as apparent diffusion coefficient from diffusion-weighted images, and metabolic biomarkers (including SUVmax, metabolic tumor volume, total lesion glycolysis, and heterogeneity index) were recorded. All patients underwent operation, and their pathologic reports served as the reference standard., Results: Thymic epithelial tumors were demonstrated in all 9 patients at pathologic examination. Tumor contour (P = 0.012) and shape (P = 0.033) had an association with the World Health Organization subtype, and the presence of septum (P = 0.048) on MRI scans had an association with the Masaoka stage. In terms of functional and metabolic biomarkers, SUVmax (ρ = 0.683, P = 0.042) and SUV/apparent diffusion coefficient (ρ = 0.703, P = 0.035) correlated with the Masaoka stage. Metabolic tumor volume (P = 0.024), heterogeneity index (P = 0.024), and total lesion glycolysis (P = 0.048) were useful for classification between low- and high-risk thymic epithelial tumors., Conclusions: Although limited by the small number of patients enrolled, morphologic, functional, and metabolic biomarkers derived from PET/MRI scans were useful for the stratification of thymic epithelial tumors.

The hypothesis that mitochondrial dysfunction and increased superoxide levels in thymocytes over expressing Bax (Lck-Bax1 and Lck-Bax38&1) contributes to lymphomagenesis after low-dose radiation was tested. Lck-Bax1 single-transgenic and Lck-Bax38&1 double-transgenic mice were exposed to single whole-body doses of 10 or 100 cGy of (137)Cs or iron ions (1,000 MeV/n, 150 keV/μm) or silicon ions (300 MeV/n, 67 keV/μm). A 10 cGy dose of (137)Cs significantly increased the incidence and onset of thymic lymphomas in female Lck-Bax1 mice. In Lck-Bax38&1 mice, a 100 cGy dose of high-LET iron ions caused a significant dose dependent acceleration of lymphomagenesis in both males and females that was not seen with silicon ions. To determine the contribution of mitochondrial oxidative metabolism, Lck-Bax38&1 over expressing mice were crossed with knockouts of the mitochondrial protein deacetylase, Sirtuin 3 (Sirt3), which regulates superoxide metabolism. Sirt3(-/-)/Lck-Bax38&1 mice demonstrated significant increases in thymocyte superoxide levels and acceleration of lymphomagenesis (P < 0.001). These results show that lymphomagenesis in Bax over expressing animals is enhanced by radiation exposure in both an LET and gender dependent fashion. These findings support the hypothesis that mitochondrial dysfunction leads to increased superoxide levels and accelerates lymphomagenesis in Lck-Bax transgenic mice.

Background: Thymic carcinoma is a rare, malignant mediastinal tumor that is definitively distinguished from thymoma by its wide extensiveness and poor prognosis. At present, cisplatin-based triplet or quartet chemotherapy with the second generation antitumor agents, referred to as Einhorn's protocol for germ cell tumors, is used as first-line chemotherapy for advanced thymic carcinoma, though an optimal chemotherapeutic regimen has not yet been established. In this retrospective study, the effectiveness and toxicity of cisplatin and irinotecan combination chemotherapy were evaluated over a nine-year period., Patients and Methods: Patients with advanced thymic carcinoma who were treated with cisplatin and irinotecan combination chemotherapy between January 1, 2002 and December 31, 2010, were retrospectively identified from our database and medical records. The endpoints in this study were disease control, response rate, progression-free survival (PFS), and overall survival (OS). Significant hematological and non-hematological toxicities were also assessed., Results: Among identified nine patients, disease control was achieved in 8 patients (88.9%), and a clinical response was achieved in 5 (55.6%). The median PFS was 7.9 months, and the median OS was 33.8 months. One- and two-year OS were 77.7% and 55.6%, respectively. Grade 3/4 hematological toxicities were observed in 2 patients (22.2%), and Grade 3/4 non-hematological toxicities were seen in 2 patients (22.2%). No febrile neutropenia or toxic death was recorded., Conclusion: Cisplatin and irinotecan combination chemotherapy appears to be acceptable for advanced thymic carcinoma as first-line chemotherapy with respect to efficacy, toxicity, and usage in the clinical setting., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: The purpose of this study was to clarify the relationship between the tumor infiltrating lymphocytes and clinical outcome in patients with thymic carcinoma., Methods: Tissue specimens from 32 patients who underwent surgical resection for thymic carcinoma were immunohistochemically analyzed for CD4, CD8 and CD20 expression., Results: Tumor-infiltrating lymphocytes were generally more abundant in the stroma. The patients with low CD4+ lymphocytes (p=0.037) and low CD20+ lymphocytes (p=0.045) within tumor stroma showed poor survival. Furthermore, concurrent low levels of CD4+ and CD20+ (p=0.014), CD8+ and CD20+ (p=0.025), and, CD4+, CD8+, and CD20+ (p=0.025) in tumor stroma were significantly associated with poor prognosis when compared to the others group., Conclusion: Our results indicate that infiltrating CD4+, CD8+, and CD20+ lymphocytes in cancer stroma may cooperate to suppress cancer progression and their presence together appear to be prognostic factor in thymic carcinoma., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: To assess the usefulness of (18)fluorine-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for differentiating the grade of malignancy of thymic epithelial neoplasm, and to determine whether (18)F-FDG PET/CT can have a role in pretreatment evaluation and possibly modify treatment strategy., Materials and Methods: The data of 26 consecutive patients (14 males and 12 females) diagnosed with a thymic epithelial neoplasm were prospectively collected and analyzed retrospectively. All patients underwent standard clinical assessment and (18)F-FDG PET/CT. The patients were divided into two subgroups according to a simplified histologic classification: low-risk thymoma (types A, AB and B1) and high-risk thymoma (types B2, B3 and C). The maximum standardized uptake value (SUV(max)) of the tumor, the mean SUV of mediastinum, and the tumor/mediastinum (T/M) ratio (ratio of peak SUV of the tumor to mean SUV of mediastinum) were compared to determine whether the two subgroups (low-risk versus high-risk tumors) could be distinguished by (18)F-FDG PET/CT, and to test for possible correlations between (18)F-FDG uptake and disease stage., Results: There was a strong statistical correlation between SUV(max) and patient subgroup and between SUV(max) and disease stage, and an even stronger correlation between SUV(max) and patient subgroup and the T/M ratio; a T/M ratio of 2.75 emerged as the cut-off value for differentiating between low-risk and high-risk thymomas., Conclusions: (18)F-FDG PET/CT can be used a "metabolic biopsy" to divide thymic epithelial neoplasm into two subgroups of high and low risk and is useful in pretreatment staging., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Spindle cell thymomas are an uncommon subset of thymomas that have been regarded as benign by some. There are no comprehensive immunohistochemical studies focusing on this histological variant of thymoma. Therefore, our knowledge on the variability of its immunohistochemical profile is limited. Thirty cases of spindle cell thymomas were reviewed and immunohistochemical studies performed using antibodies against pancytokeratin, cytokeratin 5/6 (CK5/6), CK7, CK20, thyroid transcription factor-1 (TTF-1), S-100, CD34, chromogranin, synaptophysin, epithelial membrane antigen (EMA), calretinin, desmin, smooth muscle actin (SMA), and Bcl-2. The percentage and intensity of staining were evaluated and scored. The neoplastic thymic epithelial cells were diffusely positive for CK and CK5/6 and negative for CK20, S-100, chromogranin, and desmin in all 30 cases. Eighty three percent of cases showed variable reactivity for CK7 and Bcl-2. Although 97% of cases showed focal staining for calretinin, 23% for synaptophysin, and 13% for SMA, only a single case was TTF-1 positive. An interesting staining pattern was observed for CD34 and EMA, which stained the fibrous bands in some of the cases. EMA only reacted with the epithelial cells of 1 case. Spindle cell thymomas display a strong epithelial immunohistochemical phenotype as demonstrated by their reactivity for CK and CK5/6. However, tumor cells may also show positive staining for calretinin, Bcl-2, and synaptophysin and rarely for SMA and TTF-1, which can pose a problem in the evaluation of small mediastinoscopic biopsies in separating these tumors from other more aggressive neoplasms of either epithelial or mesenchymal origin.

Background: Thymic carcinoma is a rare intrathoracic malignant tumor, and the prognosis for patients with advanced stage of the disease is poor. However, no definitive chemotherapeutic regimen has been established for advanced thymic carcinoma in front-line settings. The efficacy and benefit of second-line or salvage chemotherapy are also unknown, as few cases or case series have been reported., Patients and Methods: We evaluated the efficacy and toxicity of S-1 monotherapy with S-1, a novel oral fluoropyrimidine agent, as salvage therapy in four consecutive patients with previously treated advanced thymic carcinoma from January, 2008 to May, 2010., Results: Two patients achieved stable disease, and two achieved partial response. Median progression-free survival was 8.1 months. Hematological toxicity was mild, but gastrointestinal toxicity led to discontinuation in two of four patients., Conclusions: We concluded that oral S-1 monotherapy is useful as second-line or later chemotherapy in previously treated patients with advanced thymic carcinoma and is a potential alternative choice for patients who cannot tolerate platinum-containing treatments., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Importance of the Field: Since first reported just over 30 years ago, some progress has been made in our understanding of thymic cancer - an extremely rare cancer - and how to treat it. However, we are far from the ultimate goal of cure for most patients., Areas Covered in This Review: This review provides an overview of the thymic gland's development; features of thymic carcinoma, including its molecular characterization, current staging, and treatment guidelines; and progress made to date for treating advanced disease, concluding with future directions and prospects., What the Reader Will Gain: As scientists apply new molecular tools to learn more about cancer, we find that even among common cancers, there exist heterogeneous subtypes necessitating different treatment paradigms. Thus, a one-size-fits-all approach to cancer treatment is being displaced with precision medicine to target the 'Achilles heel' of thymic tumors., Take Home Message: When approaching thymic carcinoma, we must identify the key driving forces to target its context(s) of vulnerability to ensure the greatest impact of treatment for patients with this extremely rare cancer.

Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in gamma-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from gamma-irradiation-induced death, because their glucocorticoid-mediated decimation in Puma-deficient mice activated cycling of stem/progenitor cells and restored thymic lymphomagenesis. Our demonstration that cycles of cell attrition and repopulation by stem/progenitor cells can drive tumorigenesis has parallels in human cancers, such as therapy-induced malignancies.

Cough is one of the most common symptom for which patients seek medical attention from primary care physicians and pulmonologists. Although tuberculosis and other lung infections are common throughout the developing world, they are not among the most common causes of chronic cough. We report a case of a 23 years old male who presenting to the outpatient clinic with chronic cough not responding to regular and symptomatic treatment that was diagnosed to have thymoma. After all the common causes for chronic cough have been ruled out, unusual causes should also be considered in the differential diagnosis.

Objectives: To report a case of multifocal cortical encephalitis associated with thymoma and to establish an association of this thymoma-related paraneoplastic syndrome with voltage-gated potassium channel antibodies., Design: Case report., Setting: University hospital., Patient: A 43-year-old woman with a history of seropositive myasthenia gravis and successfully treated invasive thymoma. Four years after thymectomy, she presented with seizure and rapidly progressive confusion and aphasia. Myasthenia gravis remained in pharmacological remission. Magnetic resonance imaging of the brain showed innumerable cortically based signal abnormalities as well as extensive left mesial temporal lobe abnormality with minimal enhancement., Results: Chest computed tomography showed abnormal pleural thickening of the left lung, which proved to be recurrent metastatic thymoma. Results of serological evaluation were positive for acetylcholine receptor, striational, and voltage-gated potassium channel antibodies. She showed partial improvement in response to immunotherapy and chemotherapy but ultimately died 2 months later of tumor complications., Conclusions: Thymoma and myasthenia gravis may be associated with other autoimmune neurological disorders including paraneoplastic encephalitis. This second case of thymoma-associated multifocal cortical encephalitis demonstrates that autoimmune encephalitis can extend to cortical regions outside the limbic system. Autoimmune encephalitis should be considered in the differential diagnosis of patients with myasthenia gravis or thymoma who develop new cognitive symptoms.

Growth hormone (GH) is important for cell growth and differentiation, has multiple effects on lymphoid tissue and may promote blast cell proliferation and cancer development. We studied the effect of GH on longevity and tumour formation in Atm-deficient mice, an established model of the human cancer prone syndrome ataxia telangiectasia (AT). AT is a devastating recessive disorder that is characterized by progressive cerebellar ataxia, immunodeficiency, chromosomal instability and cancer susceptibility. Since AT patients also show endocrinological abnormalities the question has been raised as to whether GH therapy could be beneficial and/or increase the cancer risk in AT. We found that treatment with GH significantly increased longevity of Atm-deficient mice. In addition, GH ameliorated locomotoric behaviour and improved T-cell immunity. Thus, our data demonstrated that GH treatment is not necessarily accompanied by increased cancer development in diseases with chromosomal instability and cancer susceptibility and might be beneficial for AT patients.

Purpose: Thymectomy has been widely employed in the treatment of myasthenia gravis (MG). However, little data exist in Iran demonstrating the efficacy and morbidity of thymectomy. The aim of this study was to determine the clinical features, diagnostic approach, and therapeutic outcome in patients with MG who underwent thymectomy., Methods: This historical cohort study was conducted in 3 university hospitals in Tehran. Preoperative and operative indices of 61 patients with MG who had been treated with thymectomy in these hospitals from September 2000 to July 2005 were reviewed. Among them, 20 patients were followed during one year after operation for determination of postoperative complications and one year mortality rate., Results: The most common manifestations of MG were ptosis (77.0%) and upper limbs weakness (70.4%). CT scans of the thymus showed thymus enlargement, thymoma and thymus hyperplasia in 51.5% (22/43), 11.6% (5/43) and 2.32% (1/43) of patients, respectively. The postoperative complications were found in 13.1% of patients and one year mortality rate of thymectomy was 6.6%., Conclusion: Regarding to high one year mortality rate of thymectomy in patients of MG in this study, the assessment of the factors related to the mortality and outcome of patients who underwent thymectomy in Iran are necessary.

Polymyositis revealing myasthenia gravis and malignant thymoma: a case report. The increased frequency of thymoma associated with autoimmune diseases has been well documented in the literature. However the association of polymyositis (PM) and myasthenia gravis (MG) revealing a malignant thymoma is rare. We report a case of a gentleman whose presenting symptoms were those of polymyositis.

Objective: To investigate the clinical and electrophysiological characteristics of myasthenia gravis with thymoma (MGT)., Methods: The clinical and repetitive nerve stimulation (RNS) data of 72 patients with MGT, 36 males and 36 females, and 63 patients with myasthenia gravis without thymoma (NMGT) were analyzed retrospectively., Results: The onset age of 52 of the 72 MGT patients (72.2%) was 35-59. The average onset age of the MGT patients was 39.5, older than that of the NMGT patients (29.4 yrs), and the course of the MGT patients was 13.1 months, shorter than that of the NMGT patients (29.1 months)The attack rate of the males was not significantly different than that of the females. The proportion of generalized presentation type among the MGT patients was 72.8%, higher than that among the NMGT patients (66.7%), particularly concerning the respiratory muscle (20.8% vs. 9.5%). The average time interval between the onset of symptoms and respiratory or bulbar muscle involvement of the NMGT patients were 12 and 7 months respectively, both remarkably shorter than those of the NMGT patients (26.4 and 11.6 months respectively). The abnormal RNS test yield rate of the MGT patients was 86.9%, higher than, however, not significantly that of the NMGT patients (75.0%). 97.2% of the thymoma and mediastinal abnormality could be detected through computed tomography (CT) scan on thymus. The positive rate of AchRab titer of the MGT patients was 50.0%, not significantly different from that of the NMGT patients (52.4%)., Conclusion: MGT is common in middle-aged people, both male and female. The Course is quickly progressive and generalized skeletal muscles, particularly respiratory muscles, are more involved in the MGT patients than in the NMGT patients. RNS study is a sensitive tool to identify MGT. AchRab may not be the specific antibody for recognizing MGT. CT scan is useful in differentiating thymoma preoperatively.

Aim: Infiltration of the superior vena cava (SVC) due to advanced non small cell lung cancer (NSCLC) or thymoma can be treated by prosthetic replacement or tangential resection. These two technical procedures and their results are described., Methods: From 1988 to 2002, we performed 37 SVC resections: 21 replacements with polytetrafluoroethylene (PTFE) prostheses and 16 tangential exereses. Sixteen patients affected by locally advanced NSCLC (12 T4; 4 extracapsular N2) and 5 subjects with thymoma (Stage III Masaoka) underwent prosthetic replacement of the SVC. After neoadjuvant polychemotherapy, tangential resection was performed on 12 patients with extracapsular N2 NSCLC, and in 1 patient with T4 and in 3 patients with T3a disease. We performed prosthetic replacement in 18 cases using a straight prosthesis (?18-20 mm). A bridge (10-14 cm) between the innominate vein and the right atrium was created in 3 patients. The main indication for a prosthetic replacement was infiltration of more than 30% of the circumference of the SVC. There were 4 thromboembolic complications (19%), with one intraoperative death (4.8%). Tangential resection of the SVC for infiltration <20% was performed both manually and with staplers (double clamping) without any major complications., Results: Mean survival was 23 months in those patients who had undergone PTFE replacement for T4 lung cancer and for thymoma. Mean survival was 15 months in those who had undergone tangential resections for NSCLC with extracapsular N2. We performed restaging of the tumor using chest angio-CT scan in 11 patients, one year after the operation. We found 80% patency in 7 SVC prostheses and 50% patency in 4 others: the two bridges between the left innominate vein and the right atrium appeared to be partially closed but were compensated by important collateral circles., Conclusion: SVC replacement, associated with pulmonary resection or removal of mediastinal masses, can be performed in selected cases. It should not be considered as palliative treatment because of the important perioperative risks. SVC tangential resection involves fewer surgical problems. However, since this procedure is used mostly for N2 NSCLC subjects, patients have a low mean survival in spite of adjuvant therapy.

Background: Thymoma is frequently associated with paraneoplastic diseases (PDs), most commonly with myasthenia gravis (MG). This association is thought to depend on thymoma's capacity to produce and export T lymphocytes., Objective: (1) To determine the frequency and characteristics of thymoma-associated PDs other than MG; (2) to evaluate T cell maturation in thymomas with and without PDs., Methods: We studied 260 patients with thymoma (associated with MG in 228). The occurrence of PDs was monitored together with the tumor outcome. Phenotypic characterization of thymocyte subsets in 14 thymoma samples (7 with and 7 without MG) was performed by FACS., Results: A total of 47 PDs was diagnosed in 41/260 patients (15.8 %). Neurological PDs included neuromyotonia, limbic encephalitis, polymyositis, subacute hearing loss, psychosis and sleep disorders. A broad spectrum of nonneurological PDs were observed, among these, hematological and cutaneous diseases prevailed. Like MG, these disorders occurred either in the presence of the thymoma or at different times after thymomectomy; their onset often heralded a tumor recurrence. In thymomas from MG subjects, we found an increased proportion of fully mature CD4 single positive (SP) thymocytes and a reduced frequency of CD4SPCD25(+) cells; the latter finding may reflect a deficient generation of T regulatory cells, a reduced intratumorous activation of T cells, or both., Conclusions: We confirm the strong association of thymoma with PDs. These disorders often occurred in MG patients and their course in relation to thymoma was similar to that of MG. In accordance with previous observations, we found some alterations in the intratumorous production of mature CD4(+) T cells that could be involved in the pathogenesis of paraneoplastic autoimmunity.

Objective: To investigate whether excitation-contraction (E-C) coupling of muscle is impaired in patients with myasthenia gravis (MG)., Methods: In 51 patients with generalized MG and 35 normal subjects, compound muscle action potentials (CMAPs) of the abductor pollicis brevis, and movement-related potentials using an accelerometer placed at the thumb tip were simultaneously recorded after median nerve stimulation at the wrist. The E-C coupling time (ECCT) was estimated by a latency difference between CMAP and movement-related potential. Antibodies against acetylcholine receptor (AChR), ryanodine receptor (RyR), and muscle specific receptor tyrosine kinase (MuSK) were measured by immunoassays., Results: The mean ECCT was significantly longer in patients with MG (mean+/-SEM; 2.79+/-0.1 ms; p=0.002) than in normal controls (2.52+/-0.1 ms). Among MG patients, the mean ECCT was longer for patients with thymoma than for those without it (P=0.04), and was shorter for patients treated with FK506 (an immunosuppressant and also an enhancer of RyR related Ca(2+) release) than for those not receiving this treatment (p=0.04). ECCT had no significant correlation with anti-AChR, anti-RyR, or anti-MuSK antibodies., Conclusions: In MG, E-C coupling appears to be impaired, particularly in patients with thymoma, and FK506 possibly facilitates E-C coupling., Significance: The functional implication of impaired E-C coupling is not established, but it may contribute to muscle weakness in patients with MG.

Endocrine oncology is a complex area that must determine the site of a neoplastic process and the hormonal dysregulation that ensues. Patients with endocrine tumors often have delayed diagnosis because of the nonspecific and often subtle signs and symptoms. In patients with multiple endocrine neoplasia syndromes, diagnosis and clinicopathologic correlations can be even more challenging. We report a patient with multiple endocrine neoplasia type 1 (MEN-1) and a highly complex clinical story associated with multiple atypical lesions including two pituitary adenomas, a gonadotroph macroadenoma and a corticotroph microadenoma with Crooke's hyaline change and ectopic production of corticotropin-releasing hormone (CRH) from a thymic endocrine carcinoma. These lesions resulted in a highly complex clinical story, difficult diagnoses and questions about management. This case illustrates a number of clinically relevant challenges, including the diagnosis of pituitary adenomas in MEN-1, the difficulty in diagnosing Cushing's disease, and the large differential of pituitary pathologies in this disorder, double pituitary adenomas and other decoy lesions in Cushing's disease, the pathophysiology of Crooke's hyaline change in the pituitary, and the various causes of Cushing's syndrome associated with MEN-1.

Myasthenia gravis is characterized by weakness and easy fatiguability of voluntary muscles. Myasthenic patients are sensitive to non-depolarizing relaxants. Sevoflurane, as an alternative, can be used to achieve good tracheal intubation. In this report, we present our experiences.

Objective: Myasthenia gravis (MG) may be associated with the presence of acetylcholine receptor antibodies (AChRAb) [seropositive MG (SPMG)] or their absence [seronegative MG (SNMG)]. Along with features of MG, the presence of the AChRAb may relate to the existence of other immune-mediated diseases. We sought to determine the association of SPMG with other potential autoimmune diseases., Methods: A retrospective evaluation of prospectively identified MG patients at a tertiary care center was performed, with patients separated into SPMG and SNMG. Prevalence of other immune-mediated disorders, as well as the epidemiology, sensitivity of diagnostic testing, and thymic pathology, was contrasted between both patient groups., Results: Of the 109 MG patients identified, 66% were SPMG. SPMG was associated with a greater likelihood of significant repetitive stimulation decrement, the presence of either thymoma or thymic hyperplasia, and the presence of thyroid disease. In addition, all patients with a diagnosis of diabetes, concurrent with MG, were found to be SPMG., Conclusions: AChRAb and SPMG impart not only a distinctive clinical and electrophysiological phenotype of MG, but are also associated with the heightened presence of endocrinological disease.

A patient with thymoma-associated neuromyotonia and voltage-gated potassium channel (Kv1.2 and Kv1.6) antibodies by immunoprecipitation and rat brain immunolabeling was treated successfully with immunoadsorption and cyclophosphamide. Curiously, glutamic acid decarboxylase antibodies, absent at onset, appeared later. Stiff-person syndrome was absent, but fast blink reflex recovery suggested enhanced brainstem excitability. The range of antibodies produced in thymoma-associated neuromyotonia is richer, and the timing of antibody appearance more complex, than previously suspected.

FeLV-945 is a representative isolate of the natural feline leukemia virus (FeLV) variant predominant in non-T-cell malignant, proliferative, and degenerative diseases in a geographic cohort. The FeLV-945 surface glycoprotein (SU) is closely related to natural horizontally transmissible FeLV subgroup A (FeLV-A) but was found to differ from a prototype to a larger extent than the members of FeLV-A differ among themselves. The sequence differences included point mutations restricted largely to the functional domains of SU, i.e., VRA, VRB, and PRR. Despite the sequence differences in these critical domains, measurements of receptor utilization, including host range and superinfection interference, confirmed the assignment of FeLV-945 to subgroup A. Other proviruses isolated from the cohort contained similar sequence hallmarks and were assigned to FeLV subgroup A. A provirus from cat 1046 contained a histidine-to-proline change at SU residue 6 within an SPHQ motif that was previously identified as a critical mediator of fusion events during virus entry. The 1046 pseudotype virus entered cells only in the presence of the soluble cofactor FeLIX provided in trans, but it retained an ecotropic host range even in the presence of FeLIX. The mutational changes in FeLV-945 were shown to confer significant functional differences compared to prototype FeLV-A viruses. The substitution of FeLV-945 envelope gene sequences for FeLV-A/61E sequences conferred a small but statistically significant replicative advantage in some feline cells. Moreover, substitution of the unique FeLV-945 long terminal repeat and envelope gene for those of FeLV-A/61E altered the disease spectrum entirely, from a thymic lymphoma of a T-cell origin to an as yet uncharacterized multicentric lymphoma that did not contain T cells.

Chronic intestinal pseudo-obstruction can occur as a paraneoplastic disorder, and several cases have been reported in association with thymoma or small-cell lung cancer. Autoantibodies against voltage-gated potassium channels (VGKCs) are found in acquired neuromyotonia (Isaac's syndrome), and have been reported in one case of slow transit constipation without apparent neurological disease. We describe a patient with VGKC antibodies, acquired neuromyotonia and thymoma, who first presented with a severe slow-transit constipation and in whom the gastrointestinal symptoms responded well to plasmapheresis. We suggest that VGKC antibodies might be helpful in patients with possible paraneoplastic chronic intestinal pseudo-obstruction, and a positive result should stimulate the search for a thymoma or other tumour and raise the possibility of immunotherapy., (Copyright 2005 S. Karger AG, Basel.)

Aims: To study 19 cases of primary thymic carcinoma in order to define the clinicopathological features and the precise histochemical profile of this rare and heterogeneous group of tumours of the anterior mediastinum., Methods and Results: The study group consisted of 13 males and six females, with a mean age of 58.5 years (range 29-75 years). Superior vena cava syndrome and chest pain were the main presenting symptoms. Three patients were asymptomatic. No patient had myasthenia gravis. Six different histological types were identified: neuroendocrine tumours (six patients), epidermoid carcinoma (five patients), sarcomatoid carcinoma (three patients), lymphoepithelioma-like carcinoma (two patients), mucoepidermoid carcinoma, clear cell carcinoma, and undifferentiated carcinoma (one patient each). The clear cell carcinoma was associated with a thymic cyst. No association with thymoma was observed. Surgical resection, performed in 10 cases, was complete in two. Sixteen patients received thoracic radiation, and 11 received systemic chemotherapy. Follow-up information was available in 16 cases; 12 patients presented with local or metastatic relapse, and 10 patients died of their tumour. The overall 5-year survival was 14.5%., Conclusion: Primary thymic carcinoma is a very heterogeneous group of tumours of the anterior mediastinum with an aggressive clinical behaviour, and a poor overall prognosis.

Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre-T-cell antigen receptor. Although alpha beta T-cell development is observed in IL-7- and IL-7R alpha-deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7R alpha that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7R alpha was revealed by surface staining, and increased IL-7R alpha mRNA was documented by using reverse transcriptase-polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL(+) (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]-fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.

A variety of chemicals can adversely affect the immune system and influence tumor development. The modifying potential of chemical carcinogens on the lymphoid organs and cytokine production of rats submitted to a medium-term initiation-promotion bioassay for carcinogenesis was investigated. Male Wistar rats were sequentially initiated with N-nitrosodiethylamine (DEN), N-methyl-N-nitrosourea (MNU), N-butyl-N-(4hydroxybutyl)nitrosamine (BBN), dihydroxy-di-n-propylnitrosamine (DHPN), and 1,2-dimethylhydrazine (DMH) during 4 weeks. Two initiated groups received phenobarbital (PB) or 2-acetylaminofluorene (2-AAF) for 25 weeks and two noninitiated groups received only PB or 2-AAF. A nontreated group was used as control. Lymphohematopoietic organs, liver, kidneys, lung, intestines, and Zymbal's gland were removed for histological analysis. Interleukin (IL)-2, IL-12, interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), IL-10, and transforming growth factor beta1 (TGF-beta1) levels were determined by ELISA in spleen cell culture supernatants. At the fourth week, exposure to the initiating carcinogens resulted in cell depletion of the thymus, spleen and bone marrow, and impairment of IL-2, IL-12, and IFN-gamma production. However, at the 30th week, no important alterations were observed both in lymphoid organs and cytokine production in the different groups. The results indicate that the initiating carcinogens used in the present protocol exert toxic effects on the lymphoid organs and affect the production of cytokines at the initiation step of carcinogenesis. This early and reversible depression of the immune surveillance may contribute to the survival of initiated cells facilitating the development of future neoplasia.