- Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, P. R. China;
FANG Wentao,
Email: vwtfang@hotmail.com
Thymectomy is the main treatment for thymoma and other thymic diseases. But the incidence of non-therapeutic thymectomy is high due to the difficulty in the differential diagnosis of anterior mediastinum lesions. Formerly, it was believed that the thymus gradually degraded and lost function with aging, and the preservation of the thymus was not valued. Recent studies have found that the removal of the thymus at all ages has adverse effects on overall health and leads to a significant increase in the risk of autoimmune diseases, malignancy, and all-cause mortality. Therefore, unnecessary thymectomy should be avoided. This article reviews the influence of thymectomy, including the changes of immunological indexes and clinical prognosis, and further discusses the current situation and avoidance methods of non-therapeutic thymectomy.
| 1. | Miller JF. Immunological function of the thymus. Lancet, 1961, 2(7205): 748-749. |
| 2. | Ashby KM, Hogquist KA. A guide to thymic selection of T cells. Nat Rev Immunol. 2024, 24(2): 103-107. |
| 3. | Douek DC, McFarland RD, Keiser PH, et al. Changes in thymic function with age and during the treatment of HIV infection. Nature, 1998, 396(6712): 690-695. |
| 4. | Liang Z, Dong X, Zhang Z, et al. Age-related thymic involution: Mechanisms and functional impact. Aging Cell, 2022, 21(8): e13671. |
| 5. | Ackman JB, Verzosa S, Kovach AE, et al. High rate of unnecessary thymectomy and its cause. Can computed tomography distinguish thymoma, lymphoma, thymic hyperplasia, and thymic cysts. Eur J Radiol, 2015, 84(3): 524-533. |
| 6. | Kent MS, Wang T, Gangadharan SP, et al. What is the prevalence of a "nontherapeutic" thymectomy. Ann Thorac Surg, 2014, 97(1): 276-282. |
| 7. | Fang W, Xu N, Shen Y, et al. Management of incidentally detected small anterior mediastinal nodules: Which way to go? Lung Cancer, 2022, 168: 30-35. |
| 8. | Kooshesh KA, Foy BH, Sykes DB, et al. Health consequences of thymus removal in adults. NEJM, 2023, 389: 406-417. |
| 9. | Ettinger DS, Riely GJ, Akerley W, et al. NCCN clinical practice guidelines in oncology: Thymomas and thymic carcinomas. Version 1.2023-Dec 15, 2022. |
| 10. | Narayanaswami P, Sanders DB, Wolfe G, et al. International consensus guidance for management of myasthenia gravis: 2020 update. Neurology, 2021, 96(3): 114-122. |
| 11. | Wightman SC, Shrager JB. Non-myasthenia gravis immune syndromes and the thymus: Is there a role for thymectomy. Thorac Surg Clin, 2019, 29(2): 215-225. |
| 12. | Rampinelli C, Preda L, Maniglio M, et al. Extrapulmonary malignancies detected at lung cancer screening. Radiology, 2011, 261(1): 293-299. |
| 13. | Yoon SH, Choi SH, Kang CH, et al. Incidental anterior mediastinal nodular lesions on chest CT in asymptomatic subjects. J Thorac Oncol, 2018, 13(3): 359-366. |
| 14. | Roden AC, Fang W, Shen Y, et al. Distribution of mediastinal lesions across multi-institutional, international, radiology databases. J Thorac Oncol, 2020, 15(4): 568-579. |
| 15. | Wang S, Ao Y, Jiang J, et al. How can the rate of nontherapeutic thymectomy be reduced. Interact Cardiovasc Thorac Surg, 2022, 35(3): ivac132. |
| 16. | Brearley S, Gentle TA, Baynham MI, et al. Immunodeficiency following neonatal thymectomy in man. Clin Exp Immunol, 1987, 70(2): 322-327. |
| 17. | Cavalcanti NV, Palmeira P, Jatene MB, et al. Early thymectomy is associated with long-term impairment of the immune system: A systematic review. Front Immunol, 2021, 12: 774780. |
| 18. | Gu Z, Chen C, Wang Y, et al. Video-assisted thoracoscopic surgery versus open surgery for stage Ⅰ thymic epithelial tumours: A propensity score-matched study. Eur J Cardiothorac Surg, 2018, 54(6): 1037-1044. |
| 19. | Papadimas E, Tan YK, Luo H, et al. Partial versus complete thymectomy in non-myasthenic patients with thymoma: A systematic review and meta-analysis of clinical outcomes. Heart Lung Circ, 2022, 31(1): 59-68. |
| 20. | Bains I, Thiébaut R, Yates AJ, et al. Quantifying thymic export: Combining models of naive T cell proliferation and TCR excision circle dynamics gives an explicit measure of thymic output. J Immunol, 2009, 183(7): 4329-4336. |
| 21. | Granadier D, Iovino L, Kinsella S, et al. Dynamics of thymus function and T cell receptor repertoire breadth in health and disease. Semin Immunopathol, 2021, 43(1): 119-134. |
| 22. | Deya-Martinez A, Flinn AM, Gennery AR. Neonatal thymectomy in children-accelerating the immunologic clock. J Allergy Clin Immunol, 2020, 146(2): 236-243. |
| 23. | Schadenberg AW, van den Broek T, Siemelink MA, et al. Differential homeostatic dynamics of human regulatory T-cell subsets following neonatal thymectomy. J Allergy Clin Immunol, 2014, 133(1): 277-280. |
| 24. | Gudmundsdottir J, Óskarsdóttir S, Skogberg G, et al. Early thymectomy leads to premature immunologic ageing: An 18-year follow-up. J Allergy Clin Immunol, 2016, 138(5): 1439-1443. e10. |
| 25. | Sauce D, Larsen M, Fastenackels S, et al. Lymphopenia-driven homeostatic regulation of naive T cells in elderly and thymectomized young adults. J Immunol, 2012, 189(12): 5541-5548. |
| 26. | van Gent R, Schadenberg AW, Otto SA, et al. Long-term restoration of the human T-cell compartment after thymectomy during infancy: A role for thymic regeneration. Blood, 2011, 118(3): 627-634. |
| 27. | van den Broek T, Madi A, Delemarre EM, et al. Human neonatal thymectomy induces altered B-cell responses and autoreactivity. Eur J Immunol, 2017, 47(11): 1970-1981. |
| 28. | Gao S, Jiang J, Jin C, et al. Interleukin-8 as a candidate for thymoma identification and recurrence surveillance. Nat Commun, 2020, 11(1): 4881. |
| 29. | Gudmundsdottir J, Söderling J, Berggren H, et al. Long-term clinical effects of early thymectomy: Associations with autoimmune diseases, cancer, infections, and atopic diseases. J Allergy Clin Immunol, 2018, 141(6): 2294-2297. |
| 30. | Kurobe H, Tominaga T, Sugano M, et al. Complete but not partial thymectomy in early infancy reduces T-cell-mediated immune response: three-year tracing study after pediatric cardiac surgery. J Thorac Cardiovasc Surg, 2013, 145(3): 656-662. |
| 31. | Cao Q, Yin M, Zhou Y, et al. Effect of thymectomy on cellular immune function. Front Biosci, 2011, 16(8): 3036-3042. |
| 32. | Klein L, Robey EA, Hsieh CS. Central CD4+ T cell tolerance: Deletion versus regulatory T cell differentiation. Nat Rev Immunol, 2019, 19(1): 7-18. |
| 33. | Avdimiretz N, Seitz S, Kim T, et al. Allergies and autoimmune disorders in children after heart transplantation. Clin Transplant, 2018, 32(10): e13400. |
| 34. | Halnon NJ, Cooper P, Chen DY, et al. Immune dysregulation after cardiothoracic surgery and incidental thymectomy: Maintenance of regulatory T cells despite impaired thymopoiesis. Clin Dev Immunol, 2011: 915864. Epub 2011 Jul 6. |
| 35. | Prelog M, Wilk C, Keller M, et al. Diminished response to tick-borne encephalitis vaccination in thymectomized children. Vaccine, 2008, 26(5): 595-600. |
| 36. | Zlamy M, Würzner R, Holzmann H, et al. Antibody dynamics after tick-borne encephalitis and measles-mumps-rubella vaccination in children post early thymectomy. Vaccine, 2010, 28(51): 8053-8060. |
| 37. | Sun X, Nguyen T, Achour A, et al. Longitudinal analysis reveals age-related changes in the T cell receptor repertoire of human T cell subsets. J Clin Invest, 2022, 132(17): e158122. |
| 38. | Britanova OV, Putintseva EV, Shugay M, et al. Age-related decrease in TCR repertoire diversity measured with deep and normalized sequence profiling. J Immunol, 2014, 192(6): 2689-2698. |
| 39. | Sempowski G, Thomasch J, Gooding M, et al. Effect of thymectomy on human peripheral blood T cell pools in myasthenia gravis. J Immunol, 2001, 166(4): 2808-2817. |
| 40. | Coussens LM, Zitvogel L, Palucka AK. Neutralizing tumor-promoting chronic inflammation: A magic bullet. Science, 2013, 339(6117): 286-291. |
| 41. | Filosso PL, Galassi C, Ruffini E, et al. Thymoma and the increased risk of developing extrathymic malignancies: A multicentre study. Eur J Cardiothorac Surg, 2013, 44(2): 219-224. |
| 42. | Gadalla SM, Rajan A, Pfeiffer R, et al. A population-based assessment of mortality and morbidity patterns among patients with thymoma. Int J Cancer, 2011, 128(11): 2688-2694. |
| 43. | Masaoka A, Yamakawa Y, Niwa H, et al. Thymectomy and malignancy. Eur J Cardiothorac Surg, 1994, 8(5): 251-253. |
| 44. | Kim A, Choi SJ, Kang CH, et al. Risk factors for developing post-thymectomy myasthenia gravis in patients with thymoma. Muscle Nerve, 2021, 63(4): 531-537. |
| 45. | Yamada Y, Yoshida S, Iwata T, et al. Risk factors for developing postthymectomy myasthenia gravis in thymoma patients. Ann Thorac Surg, 2015, 99(3): 1013-1019. |
| 46. | Chen K, Li Y, Yang H. Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications. J Autoimmun, 2022, 132: 102895. |
| 47. | Marcuse F, Hochstenbag M, Hoeijmakers JGJ, et al. Subclinical myasthenia gravis in thymomas. Lung Cancer, 2021, 152: 143-148. |
| 48. | Huang Y, Su L, Zhang Y, et al. Risk factors for postoperative myasthenic crisis after thymectomy in patients with myasthenia gravis. J Surg Res, 2021, 262: 1-5. |
| 49. | Liu Z, Yao S, Zhou Q, et al. Predictors of extubation outcomes following myasthenic crisis. J Int Med Res, 2016, 44(6): 1524-1533. |
| 50. | Chang CC, Lin TM, Chang YS, et al. Thymectomy in patients with myasthenia gravis increases the risk of autoimmune rheumatic diseases: A nationwide cohort study. Rheumatology (Oxford), 2019, 58(1): 135-143. |
| 51. | Lin TM, Chang YS, Hou TY, et al. Risk of incident autoimmune diseases in patients with thymectomy. Ann Clin Transl Neurol, 2020, 7(7): 1072-1082. |
| 52. | Giebel S, Dziaczkowska J, Wysoczanska B, et al. Lymphocyte reconstitution after allogeneic bone marrow transplantation in a previously thymectomized patient—No evidence of extrathymic T-cell maturation. Bone Marrow Transplant, 2007, 40(7): 705-706. |
| 53. | Sannier A, Stroumza N, Caligiuri G, et al. Thymic function is a major determinant of onset of antibody-mediated rejection in heart transplantation. Am J Transplant, 2018, 18(4): 964-971. |
| 54. | Li W, Wang B, Jiang ZG, et al. The role of thymus preservation in parathyroid gland function and surgical completeness after bilateral central lymph node dissection for papillary thyroid cancer: A randomized controlled study. Int J Surg, 2019, 65: 1-6. |
| 55. | Boyd JD. Development of the thyroid and parathyroid glands and the thymus. Ann R Coll Surg Engl, 1950, 7(6): 455-471. |
| 56. | Sitges-Serra A, Gallego-Otaegui L, Suárez S, et al. Inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid carcinoma. Surg, 2017, 161(3): 712-719. |
| 57. | Strijbos E, van Ostaijen-Ten Dam MM, Vervat C, et al. The effect of immunosuppression or thymectomy on the response to tetanus revaccination in myasthenia gravis. J Neuroimmunol, 2022, 370: 577930. |
| 58. | Park JW, Jeong WG, Lee JE, et al. Pictorial review of mediastinal masses with an emphasis on magnetic resonance imaging. Korean J Radiol, 2021, 22(1): 139-154. |
| 59. | Ito T, Suzuki H, Sakairi Y, et al. 18F-FDG-PET/CT predicts grade of malignancy and invasive potential of thymic epithelial tumors. Gen Thorac Cardiovasc Surg, 2021, 69(2): 274-281. |
| 60. | Lococo F, Chiappetta M, Triumbari EKA, et al. Current roles of PET/CT in thymic epithelial tumours: Which evidences and which prospects? A pictorial review. Cancers (Basel), 2021, 13(23): 6091. |
| 61. | Lee SH, Yoon SH, Nam JG, et al. Distinguishing between thymic epithelial tumors and benign cysts via computed tomography. Korean J Radiol, 2019, 20(4): 671-682. |
| 62. | Wang S, Lin M, Yang X, et al. A novel predictive model for distinguishing mediastinal lymphomas from thymic epithelial tumours. Eur J Cardiothorac Surg, 2022, 62(6): ezac459. |
| 63. | Shiiya H, Ujiie H, Hida Y, et al. Elevated serum CYFRA 21-1 level as a diagnostic marker for thymic carcinoma. Thorac Cancer, 2021, 12(21): 2933-2942. |
| 64. | Munden RF, Carter BW, Chiles C, et al. Managing incidental findings on thoracic CT: Mediastinal and cardiovascular findings. A white paper of the ACR incidental findings committee. J Am Coll Radiol, 2018, 15(8): 1087-1096. |
- 1. Miller JF. Immunological function of the thymus. Lancet, 1961, 2(7205): 748-749.
- 2. Ashby KM, Hogquist KA. A guide to thymic selection of T cells. Nat Rev Immunol. 2024, 24(2): 103-107.
- 3. Douek DC, McFarland RD, Keiser PH, et al. Changes in thymic function with age and during the treatment of HIV infection. Nature, 1998, 396(6712): 690-695.
- 4. Liang Z, Dong X, Zhang Z, et al. Age-related thymic involution: Mechanisms and functional impact. Aging Cell, 2022, 21(8): e13671.
- 5. Ackman JB, Verzosa S, Kovach AE, et al. High rate of unnecessary thymectomy and its cause. Can computed tomography distinguish thymoma, lymphoma, thymic hyperplasia, and thymic cysts. Eur J Radiol, 2015, 84(3): 524-533.
- 6. Kent MS, Wang T, Gangadharan SP, et al. What is the prevalence of a "nontherapeutic" thymectomy. Ann Thorac Surg, 2014, 97(1): 276-282.
- 7. Fang W, Xu N, Shen Y, et al. Management of incidentally detected small anterior mediastinal nodules: Which way to go? Lung Cancer, 2022, 168: 30-35.
- 8. Kooshesh KA, Foy BH, Sykes DB, et al. Health consequences of thymus removal in adults. NEJM, 2023, 389: 406-417.
- 9. Ettinger DS, Riely GJ, Akerley W, et al. NCCN clinical practice guidelines in oncology: Thymomas and thymic carcinomas. Version 1.2023-Dec 15, 2022.
- 10. Narayanaswami P, Sanders DB, Wolfe G, et al. International consensus guidance for management of myasthenia gravis: 2020 update. Neurology, 2021, 96(3): 114-122.
- 11. Wightman SC, Shrager JB. Non-myasthenia gravis immune syndromes and the thymus: Is there a role for thymectomy. Thorac Surg Clin, 2019, 29(2): 215-225.
- 12. Rampinelli C, Preda L, Maniglio M, et al. Extrapulmonary malignancies detected at lung cancer screening. Radiology, 2011, 261(1): 293-299.
- 13. Yoon SH, Choi SH, Kang CH, et al. Incidental anterior mediastinal nodular lesions on chest CT in asymptomatic subjects. J Thorac Oncol, 2018, 13(3): 359-366.
- 14. Roden AC, Fang W, Shen Y, et al. Distribution of mediastinal lesions across multi-institutional, international, radiology databases. J Thorac Oncol, 2020, 15(4): 568-579.
- 15. Wang S, Ao Y, Jiang J, et al. How can the rate of nontherapeutic thymectomy be reduced. Interact Cardiovasc Thorac Surg, 2022, 35(3): ivac132.
- 16. Brearley S, Gentle TA, Baynham MI, et al. Immunodeficiency following neonatal thymectomy in man. Clin Exp Immunol, 1987, 70(2): 322-327.
- 17. Cavalcanti NV, Palmeira P, Jatene MB, et al. Early thymectomy is associated with long-term impairment of the immune system: A systematic review. Front Immunol, 2021, 12: 774780.
- 18. Gu Z, Chen C, Wang Y, et al. Video-assisted thoracoscopic surgery versus open surgery for stage Ⅰ thymic epithelial tumours: A propensity score-matched study. Eur J Cardiothorac Surg, 2018, 54(6): 1037-1044.
- 19. Papadimas E, Tan YK, Luo H, et al. Partial versus complete thymectomy in non-myasthenic patients with thymoma: A systematic review and meta-analysis of clinical outcomes. Heart Lung Circ, 2022, 31(1): 59-68.
- 20. Bains I, Thiébaut R, Yates AJ, et al. Quantifying thymic export: Combining models of naive T cell proliferation and TCR excision circle dynamics gives an explicit measure of thymic output. J Immunol, 2009, 183(7): 4329-4336.
- 21. Granadier D, Iovino L, Kinsella S, et al. Dynamics of thymus function and T cell receptor repertoire breadth in health and disease. Semin Immunopathol, 2021, 43(1): 119-134.
- 22. Deya-Martinez A, Flinn AM, Gennery AR. Neonatal thymectomy in children-accelerating the immunologic clock. J Allergy Clin Immunol, 2020, 146(2): 236-243.
- 23. Schadenberg AW, van den Broek T, Siemelink MA, et al. Differential homeostatic dynamics of human regulatory T-cell subsets following neonatal thymectomy. J Allergy Clin Immunol, 2014, 133(1): 277-280.
- 24. Gudmundsdottir J, Óskarsdóttir S, Skogberg G, et al. Early thymectomy leads to premature immunologic ageing: An 18-year follow-up. J Allergy Clin Immunol, 2016, 138(5): 1439-1443. e10.
- 25. Sauce D, Larsen M, Fastenackels S, et al. Lymphopenia-driven homeostatic regulation of naive T cells in elderly and thymectomized young adults. J Immunol, 2012, 189(12): 5541-5548.
- 26. van Gent R, Schadenberg AW, Otto SA, et al. Long-term restoration of the human T-cell compartment after thymectomy during infancy: A role for thymic regeneration. Blood, 2011, 118(3): 627-634.
- 27. van den Broek T, Madi A, Delemarre EM, et al. Human neonatal thymectomy induces altered B-cell responses and autoreactivity. Eur J Immunol, 2017, 47(11): 1970-1981.
- 28. Gao S, Jiang J, Jin C, et al. Interleukin-8 as a candidate for thymoma identification and recurrence surveillance. Nat Commun, 2020, 11(1): 4881.
- 29. Gudmundsdottir J, Söderling J, Berggren H, et al. Long-term clinical effects of early thymectomy: Associations with autoimmune diseases, cancer, infections, and atopic diseases. J Allergy Clin Immunol, 2018, 141(6): 2294-2297.
- 30. Kurobe H, Tominaga T, Sugano M, et al. Complete but not partial thymectomy in early infancy reduces T-cell-mediated immune response: three-year tracing study after pediatric cardiac surgery. J Thorac Cardiovasc Surg, 2013, 145(3): 656-662.
- 31. Cao Q, Yin M, Zhou Y, et al. Effect of thymectomy on cellular immune function. Front Biosci, 2011, 16(8): 3036-3042.
- 32. Klein L, Robey EA, Hsieh CS. Central CD4+ T cell tolerance: Deletion versus regulatory T cell differentiation. Nat Rev Immunol, 2019, 19(1): 7-18.
- 33. Avdimiretz N, Seitz S, Kim T, et al. Allergies and autoimmune disorders in children after heart transplantation. Clin Transplant, 2018, 32(10): e13400.
- 34. Halnon NJ, Cooper P, Chen DY, et al. Immune dysregulation after cardiothoracic surgery and incidental thymectomy: Maintenance of regulatory T cells despite impaired thymopoiesis. Clin Dev Immunol, 2011: 915864. Epub 2011 Jul 6.
- 35. Prelog M, Wilk C, Keller M, et al. Diminished response to tick-borne encephalitis vaccination in thymectomized children. Vaccine, 2008, 26(5): 595-600.
- 36. Zlamy M, Würzner R, Holzmann H, et al. Antibody dynamics after tick-borne encephalitis and measles-mumps-rubella vaccination in children post early thymectomy. Vaccine, 2010, 28(51): 8053-8060.
- 37. Sun X, Nguyen T, Achour A, et al. Longitudinal analysis reveals age-related changes in the T cell receptor repertoire of human T cell subsets. J Clin Invest, 2022, 132(17): e158122.
- 38. Britanova OV, Putintseva EV, Shugay M, et al. Age-related decrease in TCR repertoire diversity measured with deep and normalized sequence profiling. J Immunol, 2014, 192(6): 2689-2698.
- 39. Sempowski G, Thomasch J, Gooding M, et al. Effect of thymectomy on human peripheral blood T cell pools in myasthenia gravis. J Immunol, 2001, 166(4): 2808-2817.
- 40. Coussens LM, Zitvogel L, Palucka AK. Neutralizing tumor-promoting chronic inflammation: A magic bullet. Science, 2013, 339(6117): 286-291.
- 41. Filosso PL, Galassi C, Ruffini E, et al. Thymoma and the increased risk of developing extrathymic malignancies: A multicentre study. Eur J Cardiothorac Surg, 2013, 44(2): 219-224.
- 42. Gadalla SM, Rajan A, Pfeiffer R, et al. A population-based assessment of mortality and morbidity patterns among patients with thymoma. Int J Cancer, 2011, 128(11): 2688-2694.
- 43. Masaoka A, Yamakawa Y, Niwa H, et al. Thymectomy and malignancy. Eur J Cardiothorac Surg, 1994, 8(5): 251-253.
- 44. Kim A, Choi SJ, Kang CH, et al. Risk factors for developing post-thymectomy myasthenia gravis in patients with thymoma. Muscle Nerve, 2021, 63(4): 531-537.
- 45. Yamada Y, Yoshida S, Iwata T, et al. Risk factors for developing postthymectomy myasthenia gravis in thymoma patients. Ann Thorac Surg, 2015, 99(3): 1013-1019.
- 46. Chen K, Li Y, Yang H. Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications. J Autoimmun, 2022, 132: 102895.
- 47. Marcuse F, Hochstenbag M, Hoeijmakers JGJ, et al. Subclinical myasthenia gravis in thymomas. Lung Cancer, 2021, 152: 143-148.
- 48. Huang Y, Su L, Zhang Y, et al. Risk factors for postoperative myasthenic crisis after thymectomy in patients with myasthenia gravis. J Surg Res, 2021, 262: 1-5.
- 49. Liu Z, Yao S, Zhou Q, et al. Predictors of extubation outcomes following myasthenic crisis. J Int Med Res, 2016, 44(6): 1524-1533.
- 50. Chang CC, Lin TM, Chang YS, et al. Thymectomy in patients with myasthenia gravis increases the risk of autoimmune rheumatic diseases: A nationwide cohort study. Rheumatology (Oxford), 2019, 58(1): 135-143.
- 51. Lin TM, Chang YS, Hou TY, et al. Risk of incident autoimmune diseases in patients with thymectomy. Ann Clin Transl Neurol, 2020, 7(7): 1072-1082.
- 52. Giebel S, Dziaczkowska J, Wysoczanska B, et al. Lymphocyte reconstitution after allogeneic bone marrow transplantation in a previously thymectomized patient—No evidence of extrathymic T-cell maturation. Bone Marrow Transplant, 2007, 40(7): 705-706.
- 53. Sannier A, Stroumza N, Caligiuri G, et al. Thymic function is a major determinant of onset of antibody-mediated rejection in heart transplantation. Am J Transplant, 2018, 18(4): 964-971.
- 54. Li W, Wang B, Jiang ZG, et al. The role of thymus preservation in parathyroid gland function and surgical completeness after bilateral central lymph node dissection for papillary thyroid cancer: A randomized controlled study. Int J Surg, 2019, 65: 1-6.
- 55. Boyd JD. Development of the thyroid and parathyroid glands and the thymus. Ann R Coll Surg Engl, 1950, 7(6): 455-471.
- 56. Sitges-Serra A, Gallego-Otaegui L, Suárez S, et al. Inadvertent parathyroidectomy during total thyroidectomy and central neck dissection for papillary thyroid carcinoma. Surg, 2017, 161(3): 712-719.
- 57. Strijbos E, van Ostaijen-Ten Dam MM, Vervat C, et al. The effect of immunosuppression or thymectomy on the response to tetanus revaccination in myasthenia gravis. J Neuroimmunol, 2022, 370: 577930.
- 58. Park JW, Jeong WG, Lee JE, et al. Pictorial review of mediastinal masses with an emphasis on magnetic resonance imaging. Korean J Radiol, 2021, 22(1): 139-154.
- 59. Ito T, Suzuki H, Sakairi Y, et al. 18F-FDG-PET/CT predicts grade of malignancy and invasive potential of thymic epithelial tumors. Gen Thorac Cardiovasc Surg, 2021, 69(2): 274-281.
- 60. Lococo F, Chiappetta M, Triumbari EKA, et al. Current roles of PET/CT in thymic epithelial tumours: Which evidences and which prospects? A pictorial review. Cancers (Basel), 2021, 13(23): 6091.
- 61. Lee SH, Yoon SH, Nam JG, et al. Distinguishing between thymic epithelial tumors and benign cysts via computed tomography. Korean J Radiol, 2019, 20(4): 671-682.
- 62. Wang S, Lin M, Yang X, et al. A novel predictive model for distinguishing mediastinal lymphomas from thymic epithelial tumours. Eur J Cardiothorac Surg, 2022, 62(6): ezac459.
- 63. Shiiya H, Ujiie H, Hida Y, et al. Elevated serum CYFRA 21-1 level as a diagnostic marker for thymic carcinoma. Thorac Cancer, 2021, 12(21): 2933-2942.
- 64. Munden RF, Carter BW, Chiles C, et al. Managing incidental findings on thoracic CT: Mediastinal and cardiovascular findings. A white paper of the ACR incidental findings committee. J Am Coll Radiol, 2018, 15(8): 1087-1096.