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[Thymic hyperplasia: A study of 46 cases]. Ann Pathol 2021; 41:544-548. [PMID: 34674894 DOI: 10.1016/j.annpat.2021.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Thymic hyperplasia presents as an anterior mediastinal mass and poses important diagnostic and therapeutic challenge. Two types of thymic hyperplasia are described: true hyperplasia and follicular hyperplasie. Literature data are peculiar concerning both entities. We aimed to describe the clinical and microscopic characteristics of thymic hyperplasia through a single institution experience during an 11-year-period. METHODS Thymic hyperplasia diagnosed during the period between 2009 and 2020 were included. RESULTS In all, 46 thymic hyperplasias were diagnosed. The 46 patients consisted in 33 women and 13 men with a mean age of 30 years. Microscopic diagnosis concluded to a follicular hyperplasia in 12 cases and a true thymic hyperplasia in 34 cases. The diagnosis of true thymic hyperplasia posed a diagnostic challenge with an involuted thymus in 1 case and a thymolipoma in 1 case. The confrontation with the clinical data allowed retaining the diagnosis. CONCLUSION The diagnosis of thymic hyperplasia is based on microscopic features. The confrontation with clinical data and the measurements of the thymus according to the age allow to retain the diagnosis in most challenging cases.
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Weis CA, Schalke B, Ströbel P, Marx A. Challenging the current model of early-onset myasthenia gravis pathogenesis in the light of the MGTX trial and histological heterogeneity of thymectomy specimens. Ann N Y Acad Sci 2018; 1413:82-91. [DOI: 10.1111/nyas.13563] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 10/23/2017] [Accepted: 10/26/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim; University of Heidelberg; Mannheim Germany
| | - Berthold Schalke
- Department of Neurology, University Hospital Regensburg; University of Regensburg; Regensburg Germany
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center Göttingen; University of Göttingen; Göttingen Germany
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim; University of Heidelberg; Mannheim Germany
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3
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Evoli A, Minicuci GM, Vitaliani R, Battaglia A, Della Marca G, Lauriola L, Fattorossi A. Paraneoplastic diseases associated with thymoma. J Neurol 2007; 254:756-62. [PMID: 17325820 DOI: 10.1007/s00415-006-0429-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/16/2006] [Accepted: 09/28/2006] [Indexed: 12/12/2022]
Abstract
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.
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Affiliation(s)
- Amelia Evoli
- Dept. of Neurosciences, Catholic University, Largo F. Vito, 00168 Rome, Italy.
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Gilboa-Geffen A, Lacoste PP, Soreq L, Cizeron-Clairac G, Le Panse R, Truffault F, Shaked I, Soreq H, Berrih-Aknin S. The thymic theme of acetylcholinesterase splice variants in myasthenia gravis. Blood 2007; 109:4383-91. [PMID: 17272501 DOI: 10.1182/blood-2006-07-033373] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholinergic signaling and acetylcholinesterase (AChE) influence immune response and inflammation. Autoimmune myasthenia gravis (MG) is mediated by antibodies to the acetylcholine receptor and current therapy is based on anti-AChE drugs. MG is associated with thymic hyperplasia, showing signs of inflammation. The objectives of this study were to analyze the involvement of AChE variants in thymic hyperplasia. We found lower hydrolytic activities in the MG thymus compared with adult controls, accompanied by translocation of AChE-R from the cytoplasm to the membrane and increased expression of the signaling protein kinase PKC-betaII. To explore possible causal association of AChE-R changes with thymic composition and function, we used an AChE-R transgenic model and showed smaller thymic medulla compared with strain-matched controls, indicating that AChE-R overexpression interferes with thymic differentiation mechanisms. Interestingly, AChE-R transgenic mice showed increased numbers of CD4(+)CD8(+) cells that were considerably more resistant in vitro to apoptosis than normal thymocytes, suggesting possibly altered positive selection. We further analyzed microarray data of MG thymic hyperplasia compared with healthy controls and found continuous and discrete changes in AChE-annotated GO categories. Together, these findings show that modified AChE gene expression and properties are causally involved in thymic function and development.
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Roxanis I, Micklem K, Willcox N. True epithelial hyperplasia in the thymus of early-onset myasthenia gravis patients: implications for immunopathogenesis. J Neuroimmunol 2001; 112:163-73. [PMID: 11108945 DOI: 10.1016/s0165-5728(00)00415-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The early-onset myasthenia gravis (EOMG) thymus shows characteristic medullary epithelial bands (MEB), greatly expanded perivascular infiltrates and fenestrations of the intervening basement membranes. We now compare epithelial expression of epidermal growth factor receptor (EGFR) and many integrins in EOMG and control samples. The main differences are striking/consistent thickening (in MEB) of what is normally a monolayer of perivascular epithelium, with focal protrusion into the infiltrates. This evidently hyperplastic epithelial subpopulation also strongly expresses EGFR and certain integrins. We suggest that its enhanced interactions with the locally increased extracellular matrix protein deposits may play an important role in autosensitization.
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Affiliation(s)
- I Roxanis
- Neurosciences Group, Institute of Molecular Medicine, John Radcliffe Hospital, Headington, OX3 9DS, Oxford, UK
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6
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Inoue M, Okumura M, Miyoshi S, Shiono H, Fukuhara K, Kadota Y, Shirakura R, Matsuda H. Impaired expression of MHC class II molecules in response to interferon-gamma (IFN-gamma) on human thymoma neoplastic epithelial cells. Clin Exp Immunol 1999; 117:1-7. [PMID: 10403908 PMCID: PMC1905478 DOI: 10.1046/j.1365-2249.1999.00933.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A human thymoma is a neoplasm derived from the thymic epithelial cell, and is well known for its association with autoimmune diseases, especially myasthenia gravis. The neoplastic epithelial cells of thymoma clearly retain thymic epithelial functions, but the development of T cells in thymoma is somewhat impaired. In this study, we quantified by flow cytometry the in vitro expression of MHC molecules on neoplastic epithelial cells precultured with IFN-gamma. While MHC class I expression was comparable with that on normal thymic epithelial cells, the level of MHC class II molecules on neoplastic epithelial cells was lower than in controls, and also varied greatly from case to case. Additionally, there was a significant positive correlation between the expression level of MHC class II and the proportion of mature CD3+ cells in the CD4+CD8- subset. Thus, accumulation of CD3-CD4+CD8- cells in thymoma may result from impaired expression of the MHC class II molecules, suggesting that the function of the neoplastic epithelial cells might determine the maturation and the positively selected repertoire of T cells in thymomas.
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Affiliation(s)
- M Inoue
- First Department of Surgery, Division of Organ Transplantation Biomedical Research Centre, Osaka University Medical School, Osaka, Japan
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Navaneetham D, Penn AS, Howard JF, Conti-Fine BM. TCR-Vbeta usage in the thymus and blood of myasthenia gravis patients. J Autoimmun 1998; 11:621-33. [PMID: 9878084 DOI: 10.1006/jaut.1998.0246] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In myasthenia gravis (MG) the muscle acetylcholine receptor (AChR) is the target of an autoimmune response. The anti-AChR response may originate in the thymus, which is abnormal in most MG patients and contains anti-AChR T and B cells. Microbial superantigens (sAg) may trigger autoimmune responses and in this study we sought clues as to whether sAg play a role in the pathogenesis of MG. We investigated the frequency of use of the different TCR Vbeta families by the thymus and blood T cells in MG patients and in control subjects, using a multi-primer PCR assay. Identical TCR-Vbeta usage was found in the thymi of MG patients and controls, except Vbeta2, which showed a small increase in MG patients' thymi. Blood T cells of MG patients used Vbeta4, Vbeta6, Vbeta15, Vbeta16 and Vbeta24 significantly more than those of the controls. Vbeta4 and Vbeta6 are the gene families most frequently used by anti-AChR CD4(+) cells in MG patients. Blood T cells from MG patients used Vbeta12, Vbeta14, Vbeta17 and Vbeta18 significantly less than controls. MG patients used Vbeta4 and Vbeta6 significantly more in the blood than in the thymus, while the opposite occurred for Vbeta7, Vbeta12 and Vbeta14. Controls used Vbeta17 more and Vbeta24 less in the blood than in the thymus. The preferential expansion of Vbeta4 and Vbeta6 in MG patients might reflect the immunodominance of certain AChR epitopes, or the action of a sAg outside the thymus. The minimal differences in the TCR-Vbeta usage in the blood and thymus of control subjects might be due to expansion of T cell clones specific for common antigens. Identical Vbeta usage in the thymi of MG patients and controls does not support an important role of the thymus as the location of anti-AChR sensitization when MG is clinically evident. The differences observed in the Vbeta usage in blood and thymi of MG patients are likely to be due to preferential Vbeta usage by the anti-AChR T cells in the blood.
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Affiliation(s)
- D Navaneetham
- College of Biological Sciences, University of Minnesota, St. Paul, MN, 55108, USA
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8
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Nagvekar N, Moody AM, Moss P, Roxanis I, Curnow J, Beeson D, Pantic N, Newsom-Davis J, Vincent A, Willcox N. A pathogenetic role for the thymoma in myasthenia gravis. Autosensitization of IL-4- producing T cell clones recognizing extracellular acetylcholine receptor epitopes presented by minority class II isotypes. J Clin Invest 1998; 101:2268-77. [PMID: 9593783 PMCID: PMC508815 DOI: 10.1172/jci2068] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Myasthenia gravis (MG) is caused by helper T cell-dependent autoantibodies against the muscle acetylcholine receptor (AChR). Thymic epithelial tumors (thymomas) occur in 10% of MG patients, but their autoimmunizing potential is unclear. They express mRNAs encoding AChR alpha and epsilon subunits, and might aberrantly select or sensitize developing thymocytes or recirculating peripheral T cells against AChR epitopes. Alternatively, there could be defective self-tolerance induction in the abundant maturing thymocytes that they usually generate. For the first time, we have isolated and characterized AChR-specific T cell clones from two MG thymomas. They recognize extracellular epitopes (alpha75-90 and alpha149-158) which are processed very efficiently from muscle AChR. Both clones express CD4 and CD8alpha, and have a Th-0 cytokine profile, producing IL-4 as well as IFN-gamma. They are restricted to HLA-DP14 and DR52a; expression of these minority isotypes was strong on professional antigen-presenting cells in the donors' tumors, although it is generally weak in the periphery. The two clones' T cell receptor beta chains are different, but their alpha chain sequences are very similar. These resemblances, and the striking contrasts with T cells previously cloned from non-thymoma patients, show that thymomas generate and actively induce specific T cells rather than merely failing to tolerize them against self antigens.
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Affiliation(s)
- N Nagvekar
- Neuroscience Group, Institute for Molecular Medicine, University of Oxford, OX3 9DS, United Kingdom
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Beeson D, Bond AP, Corlett L, Curnow SJ, Hill ME, Jacobson LW, MacLennan C, Meager A, Moody AM, Moss P, Nagvekar N, Newsom-Davis J, Pantic N, Roxanis I, Spack EG, Vincent A, Willcox N. Thymus, thymoma, and specific T cells in myasthenia gravis. Ann N Y Acad Sci 1998; 841:371-87. [PMID: 9668262 DOI: 10.1111/j.1749-6632.1998.tb10950.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D Beeson
- Institute of Molecular Medicine, University of Oxford, United Kingdom
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10
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Chilosi M, Mariuzzi G. Ormond's disease: Aspetti anatomo-patologici: Ormond's disease: Histopathological features. Urologia 1998. [DOI: 10.1177/039156039806500214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Histopathological studies have significantly contributed to clarifing the pathogenetic mechanisms of idiopathic retroperitoneal fibrosis (Ormond's disease), confirming in most cases its inflammatory nature. In this review we describe the principal pathologic features of the lesion, describing the different inflammatory and fibrogenic cell components. In addition, the differential diagnosis of Ormond's disease and the clinical role of histopathology and immunophenotypical analysis are briefly discussed.
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Affiliation(s)
- M. Chilosi
- Istituto di Anatomia Patologica - Policlinico Borgo Roma - Università degli Studi - Verona
- Istituto di Anatomia Patologica, Policlinico Borgo Roma - 37134 Verona - Italy
| | - G. Mariuzzi
- Istituto di Anatomia Patologica - Policlinico Borgo Roma - Università degli Studi - Verona
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11
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Yoshitake T, Masunaga A, Sugawara I, Nakamura H, Itoyama S, Oka T. A comparative histological and immunohistochemical study of thymomas with and without myasthenia gravis. Surg Today 1994; 24:1044-9. [PMID: 7780226 DOI: 10.1007/bf01367454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Because myasthenia gravis (MG) is frequently associated with thymoma, in this study the histological patterns of thymomas from 11 patients with MG (group A) were compared with those from 8 patients without MG (group B). An immunohistochemical examination was also conducted to determine whether the thymoma associated with MG is the site where autoantibodies are produced or secreted. Lymphoid follicles (LFs) and medullary differentiation (MD) were histologically evident only in group A in 4 and 5 patients, respectively, but were completely absent in group B. Moreover, an elevated serum antiacetylcholine receptor antibody titer was found in group A. Typical LFs were histologically and phenotypically similar to the lymph follicles seen in reactive lymph nodes. The number of cells expressing the B-cell antigen differed between groups A and B in terms of IgM- or IgD-bearing cells in the mantle zones and LN1-positive cells in the germinal centers of LFs. Thus, it is thought that LFs consist of B cells under stimulatory conditions and that these B cells may have the potential to produce autoantibodies in MG; however, since the differentiation of these Ig-bearing cells to plasma cells was hardly evident, the thymoma itself is possibly not the site of autoantibody production or secretion in patients with MG.
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Affiliation(s)
- T Yoshitake
- Department of Surgery, Saitama Medical Center, Saitama Medical School, Japan
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12
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Fend F, Kirchner T, Marx A, Müller-Hermelink HK. B-cells in thymic epithelial tumours. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf02899268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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Mihovilovic M, Hulette C, Mittelstaedt J, Austin C, Roses AD. Nicotinic neuronal acetylcholine receptor alpha-3 subunit transcription in normal and myasthenic thymus. Ann N Y Acad Sci 1993; 681:83-96. [PMID: 8357212 DOI: 10.1111/j.1749-6632.1993.tb22872.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Thymic transcription of the alpha-3 subunit of the AChR was studied through sequencing and PCR analysis of thymic cDNA clones, Northern blotting, and ribonuclease protection assays. This analysis revealed at least three, 3' end sequence variants for the alpha-3 subunit as well as a variant that results from the alternative splicing of an antisense 122 bp Alu sequence between exons 5 and 6 of the normal transcript. The spliced Alu sequence not only shifts the exon 6 reading frame but also carries an in-frame stop codon. If translated, this variant transcript would produce a truncated peptide lacking the fourth transmembrane domain of the subunit and carrying a carboxy terminus dodecapeptide not found in any other known AChR subunit sequence. The putative variant subunit may lack biological activity and should differ antigenically from its normal counterpart. In comparing the normal, the MG hypertrophic, and the MG thymoma for transcription of the alpha-3 subunit and its 122 bp variant, it was found that there were no qualitative or quantitative changes in alpha-3 transcript expression in the MG hypertrophic thymi. Thymomas, however, showed an overall decrease in alpha-3 transcription and a comparative increase in beta-amyloid precursor transcription. The decrease in the levels of alpha-3 transcription in thymomas may be related to the proliferation of thymic epithelial cells.
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Affiliation(s)
- M Mihovilovic
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
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Matsui M, Wada H, Ohta M, Kuroda Y. Potential role of thymoma and other mediastinal tumors in the pathogenesis of myasthenia gravis. J Neuroimmunol 1993; 44:171-6. [PMID: 8505406 DOI: 10.1016/0165-5728(93)90039-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ten non-myasthenic thymoma patients and 12 patients with other mediastinal tumors were compared with 19 myasthenic thymoma patients with regard to an increase in circulating CD4+CD8+ cells and the presence of anti-acetylcholine receptor and anti-skeletal muscle antibodies. Although seven non-myasthenic thymoma patients showed positive results, the proportion of myasthenic thymoma patients who were positive for more than one parameter was significantly larger than that of non-myasthenic thymoma patients (89% vs. 40%). Moreover, one patient with a non-thymomatous mediastinal tumor showing a high CD4+CD8+ cell level had a recent history of seronegative myasthenia gravis. The results indicate that measurements of these parameters may predict the risk of the development of MG in patients with thymoma and other mediastinal tumors.
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Affiliation(s)
- M Matsui
- Department of Internal Medicine, Saga Medical School, Japan
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Fukai I, Masaoka A, Hashimoto T, Yamakawa Y, Mizuno T, Tanamura O, Hirokawa K, Ueda R. An immunohistologic study of the epithelial components of 81 cases of thymoma. Cancer 1992; 69:2463-8. [PMID: 1373667 DOI: 10.1002/1097-0142(19920515)69:10<2463::aid-cncr2820691014>3.0.co;2-g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Eighty-one cases of thymoma were studied immunohistologically with the use of three mouse monoclonal antibodies: one was specific for subcapsular-cortical, one for intra-cortical, and one for medullary epithelial cells. Twenty-eight (60.9%) of 46 polygonal cell thymomas were of the cortical type and 1 (2.2%) was of the medullary type. Ten (55.6%) of 18 spindle cell thymomas and 7 (41.2%) of 17 mixed cell thymomas were of the medullary type, and 1 (5.6%) of 18 spindle cell thymomas was of the cortical type. Fourteen (17.3%) of 81 thymomas were composed of epithelial cells that were triple positive immunologically; although these are unusual, they also may be present in the normal thymus. Based on these findings, triple-positive epithelium in the normal thymus consists of common stem cells that can differentiate into subcapsular-cortical, intra-cortical, and medullary epithelium; these cells may be the target cells for tumorigenesis. Epithelium in polygonal cell thymoma tends to differentiate into cortical epithelium, whereas epithelium in spindle and mixed cell thymomas differentiates into medullary epithelium.
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Affiliation(s)
- I Fukai
- Second Department of Surgery, Nagoya City University Medical School, Japan
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16
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Ferrio MF, Durelli L, Massazza U, Cavallo R, Poccardi G, Maggi G, Casadio C, Di Summa M, Bergamini L. Intrathymic lymphoid cell differentiation in myasthenia gravis: an immunophenotypic study. ITALIAN JOURNAL OF NEUROLOGICAL SCIENCES 1991; 12:569-73. [PMID: 1783535 DOI: 10.1007/bf02336953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Thymocytes express multiple different surface antigens according to their stage of maturation. We studied lymphocyte surface differentiation antigens using direct immunofluorescence technique in the thymus of 20 patients with myasthenia gravis (MG) and 10 controls undergoing cardiac surgery. Fluorescein isothiocyanate-conjugated monoclonal antibodies were used to stain thymic cell surface antigens. We found a decrease in the percent expression of CD1, CD5, and CD7 surface antigens and a significant increase of CD20+ cells in myasthenic thymus compared with the controls. The changes in the percent expression of CD3, CD4, and CD8 antigens were not significant. These data suggest both the decrease in the immunophenotypes corresponding to cortical thymocytes (probably reflecting the cortical atrophy of the MG thymus) and the increase of mature B Cells (CD20+), which may participate in an active immune response.
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Affiliation(s)
- M F Ferrio
- Clinica Neurologica, Università di Torino
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17
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Popeskovic L, Apostolski S, Isakovic K. Epithelial cells and macrophages in myasthenia gravis thymus culture. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1990; 56:323-33. [PMID: 2390810 DOI: 10.1016/0090-1229(90)90153-h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Monolayer culture of thymic nonlymphoid cells derived from female patients with myasthenia gravis (MG) and individuals who underwent heart surgery was established to investigate the cellular composition of the thymic microenvironment and the interaction of nonlymphoid cells with autologous thymocytes. Thymic epithelial cells were identified by immunoperoxidase staining using monoclonal antibodies (mAbs) specific for cytokeratin and MR6 and MR19 antigens expressed on cortical and medullary epithelial cells, respectively. Macrophages were characterized by determination of alpha-naphthyl acetate esterase activity and detection of M1 antigen by mAb. It was demonstrated that in MG thymus cultures the number of cortical MR6+ epithelial cells is significantly reduced, and the ability of the remaining MR6+ cells to bind autologous thymocytes is markedly affected. On the other hand, the number of macrophages and the interaction of those cells with thymocytes were similar in MG and control thymus cultures. Since MR6+ epithelial cells are numerically and functionally affected in MG, maturational events of T cells occurring in the inner cortex may be altered. The mechanisms underlying the induction and expansion of T helper clones in MG are discussed.
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Affiliation(s)
- L Popeskovic
- Immunology Research Center, University Clinical Center, Belgrade, Yugoslavia
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Scarpa A, Chilosi M, Capelli P, Bonetti F, Menestrina F, Zamboni G, Pizzolo G, Palestro G, Fiore Donati L, Tridente G. Expression and gene rearrangement of the T-cell receptor in human thymomas. VIRCHOWS ARCHIV. B, CELL PATHOLOGY INCLUDING MOLECULAR PATHOLOGY 1989; 58:235-9. [PMID: 1970686 DOI: 10.1007/bf02890077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Human thymomas are epithelial neoplasms frequently associated with an exuberant lymphoid component. This mixture of epithelial cells and lymphocytes closely mimicks the organization of normal thymic cortex. However, it is not known whether thymocytes in thymoma express the T-cell receptor (TCR) for the antigen. We have analyzed the molecular configuration of TCR genes and their phenotypic expression in eight thymomas. In all we detected polyclonal rearrangements of TCR genes and cytoplasmic expression of TCR molecules in most thymocytes, thus indicating that rearranged TCR genes in thymomas are functioning genes. In addition, these findings suggest that the epithelial component of thymomas, even if neoplastic, is still capable of directing thymocyte differentiation.
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Affiliation(s)
- A Scarpa
- Istituto di Anatomia Patologica, University of Verona, Italy
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19
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Affiliation(s)
- K Henry
- Department of Histopathology, Charing Cross and Westminster Medical School, London, UK
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20
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Janossy G, Campana D, Akbar A. Kinetics of T lymphocyte development. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1989; 79:59-99. [PMID: 2644087 DOI: 10.1007/978-3-642-73855-5_4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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21
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Schluep M, Willcox N, Ritter MA, Newsom-Davis J, Larché M, Brown AN. Myasthenia gravis thymus: clinical, histological and culture correlations. J Autoimmun 1988; 1:445-67. [PMID: 3254184 DOI: 10.1016/0896-8411(88)90067-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This paper attempts to quantitate immunohistological changes in the myasthenia gravis (MG) thymus and to correlate them with clinical and culture parameters in 40 untreated young onset patients covering a wide range of durations and serum anti-acetylcholine receptor (AChR) antibody titers. Total cellularities of both the thymic cortex and the medulla declined significantly with age. There was some hyperplasia of subcapsular and of medullary epithelial cells, often at the expense of cortex. A combined index of all hyperplastic changes correlated significantly with serum anti-AChR titre. Otherwise histological indices, e.g. of germinal centres (GC) were largely unrelated to any clinical parameters, especially duration of symptoms. Specific anti-AChR synthesis in culture (very closely related to serum titer) correlated better with the medullary lymph node-type T-cell areas; these were more widely prevalent and MG-specific. In contrast, basal and mitogen-stimulated total IgG productivity followed the GC indices more closely. We propose that the variability of GC is due to their dependence on extraneous immune complexes, and we discuss whether they or the T-cell areas are primary or secondary abnormalities. Finally, we conclude that autosensitization in MG with thymic hyperplasia and neoplasia probably arises through separate mechanisms.
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Affiliation(s)
- M Schluep
- Department of Neurological Science, Royal Free Hospital School of Medicine, London
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22
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Rouse RV, Weiss LM. Human thymomas: evidence of immunohistologically defined normal and abnormal microenvironmental differentiation. Cell Immunol 1988; 111:94-106. [PMID: 2448046 DOI: 10.1016/0008-8749(88)90054-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Fifteen human thymomas were analyzed by immunoperoxidase studies on frozen and paraffin-embedded tissue sections in an attempt to identify the existence of immunologically defined microenvironments. All nine lymphocyte predominant thymomas contained a predominance of lymphocytes bearing the phenotype of cortical thymocytes and dendritic Class II major histocompatibility complex antigen-positive epithelial cells, thus defining cortical-like microenvironments. Medullary-like foci were also seen in all of these cases. Minor phenotypic abnormalities in Leu-2 and -3 antigen expression were seen in three cases. In contrast, the two epithelial predominant thymomas and four mixed thymomas all exhibited features of aberrant microenvironmental differentiation, with only two cases showing demarcation into cortical and medullary foci. A lack of Class II major histocompatibility complex antigens was associated with a decrease in the lymphoid populations and an increase in Leu-1 antigen expression by T cells of otherwise normal cortical phenotype when lymphocytes were present. In contrast, lack of Class I antigen on epithelial cells was not associated with any abnormality in lymphocyte phenotype or microenvironmental organization. We document for the first time abnormal microenvironments in thymomas that may offer insights into understanding normal thymic differentiation.
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Affiliation(s)
- R V Rouse
- Department of Pathology, Stanford University, California 94305
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23
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Levinson AI, Zweiman B, Lisak RP. Immunopathogenesis and treatment of myasthenia gravis. J Clin Immunol 1987; 7:187-97. [PMID: 3036906 DOI: 10.1007/bf00915723] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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24
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Janossy G, Bofill M, Trejdosiewicz LK, Willcox HN, Chilosi M. Cellular differentiation of lymphoid subpopulations and their microenvironments in the human thymus. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1986; 75:89-125. [PMID: 3514162 DOI: 10.1007/978-3-642-82480-7_3] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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25
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Willcox N. The cellular immunology of myasthenia gravis. LA RICERCA IN CLINICA E IN LABORATORIO 1985; 15:199-204. [PMID: 3878566 DOI: 10.1007/bf03029191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The possible role of the thymus in autosensitization to the acetylcholine receptor (AChR) in myasthenia gravis is briefly discussed, and work on autoantibody synthesis in vitro is reviewed. Whereas blood lymphocytes sometimes make anti-AChR in response to mitogens, spontaneous production is more regularly observed in cells from lymph nodes, bone marrow and, above all, thymus, where it is selectively activated. Cell separation studies imply a dominant contribution by the germinal centre cells and plasma cells there, many of which are autonomous (i.e. no longer require T cell help). The need for germinal centre-directed immunosuppressive regimes is discussed.
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