Unilocular and multilocular thymic cysts: A study on the possible histomorphological and/or clinical differences

Objective: Thymic cysts are rare mediastinal cystic pathologies and have two subtypes namely unilocular and multilocular. This study aims to investigate the clinicopathological characteristics of thymic cysts and to compare the clinical and histopathologic features of multilocular thymic cysts (MTCs) and unilocular thymic cysts (UTCs). Patients and Methods: Twenty-three patients with the diagnosis of thymic cyst between 2012 and 2020 were included. We compared the clinicopathological characteristics of unilocular and multilocular thymic cysts. Results: The mean age of patients was 43 years, ranging from 6 to 80 years. Fourteen cases were UTCs and 9 cases were MTCs. MTCs were found to be statistically more common in younger patients, and have much more histomorphological changes pointing to the complicated cysts (p<0.05). Moreover, we noted that patients with MTCs were found to be more symptomatic before diagnosis. Furthermore, in our study when we compared MTCs and UTCs, UTCs were slightly (64.2%) more frequent in female patients. Conclusion: According to our results, thymic cysts may also be seen at younger ages. MTC and UTC can have different histomorphological characteristics, such as in foreign body reaction and hemorrhage. Moreover, there can be different clinical features, such as age, gender, and symptoms, between these two subtypes.

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  • Suster S, Rosai J. Multilocular thymic cyst: an acquired reactive process. Study of 18 cases. Am J Surg Pathol 1991;15:388-98. PubMed PMID: 2006719.
  • Indeglia RA, Shea MA, Grage TB. Congenital cysts of the thymus gland. Arch Surg 1967;94:149-52. doi: 10.1001/archsurg.1967.01330070151030. PubMed PMID: 6017453.
  • Jamovi. The jamovi project. 1.6 ed2021. Accessed on December 11,2021, from http://www.jamovi.org.
  • Almofada HS, Almedemgh NI, Othman EO. Adult Cervical Thymic Cysts: A Narrative Review. Ear Nose Throat J 2022:1455613221111490. doi: 10.1177/01455613221111490. PubMed PMID: 35763329.
  • Cigliano B, Baltogiannis N, De Marco M, et al. Cervical thymic cysts. Pediatr Surg Int 2007;23:1219-25. doi: 10.1007/s00383-006-1822-5.
  • Chang A, Nataraja RM, Pudel E, Stunden R, Baré S, Pacilli M. Diagnosis and management of ectopic cervical thymus in children: Systematic review of the literature. J Pediatr Surg 2021;56:2062-8. doi: 10.1016/j.jpedsurg.2021.03.003.
  • Sturm JJ, Dedhia K, Chi DH. Diagnosis and management of cervical thymic cysts in children. Cureus 2017;9:e973. doi: 10.7759/cureus.973.
  • Michalopoulos N, Papavramidis TS, Karayannopoulou G, et al. Cervical thymic cysts in adults. Thyroid 2011;21:987-92. doi: 10.1089/thy.2010.0142.
  • Oramas DM, Moran CA. Micronodular thymomas with prominent cystic changes: A clinicopathological and immunohistochemical study of 25 cases. Int J Surg Pathol 2021;29:352-7. doi: 10.1177/1066896920963803.
  • Yasuda K, Kidokoro Y, Makishima K, et al. A rare case of combined thymoma and a multilocular thymic cyst discovered due to chest pain. Surg Case Rep 2021;7:158. doi: 10.1186/s40792-021-01243-2.
  • Syred K, Weissferdt A. non-neoplastic mediastinal cysts. Adv Anat Pathol 2020;27:294-302. doi: 10.1097/pap.0000000000000261.
  • Roden AC, Fang W, Shen Y, et al. Distribution of Mediastinal Lesions Across Multi-Institutional, International, Radiology Databases. J Thorac Oncol 2020;15:568-79. doi: 10.1016/j.jtho.2019.12.108.
  • Kim H, Yoon SH, Kim J, et al. Growth of thymic epithelial tumors and thymic cysts: Differential radiological points. Thorac Cancer 2019;10:864-71. doi: 10.1111/1759-7714.13016.
  • Zhonggao J, YiJiao W, Yongfeng W, et al. Multislice computed tomography performance in differential diagnosis of high-density thymic cyst and thymoma in lesions less than 3 cm. Thorac Cancer 2018;9:1300-4. doi: 10.1111/1759-7714.12840.
  • Nam JG, Goo JM, Park CM, Lee HJ, Lee CH, Yoon SH. Age- and gender-specific disease distribution and the diagnostic accuracy of CT for resected anterior mediastinal lesions. Thorac Cancer 2019;10:1378-87. doi: 10.1111/1759-7714.13081.
  • Minato H, Kinoshita E, Nakada S, et al. Thymic lymphoid hyperplasia with multilocular thymic cysts diagnosed before the Sjögren syndrome diagnosis. Diagn Pathol 2015;10:103. doi: 10.1186/s13000-015-0332-y.
  • Scharifker D. True thymic hyperplasia associated with a unilocular thymic cyst: an unusual combination not previously reported. Ann Diagn Pathol 2006;10:32-5. doi: 10.1016/j.anndiagpath.2005.04.005.
  • Izumi H, Nobukawa B, Takahashi K, et al. Multilocular thymic cyst associated with follicular hyperplasia: clinicopathologic study of 4 resected cases. Hum Pathol 2005;36:841-4. doi: 10.1016/j.humpath.2005.05.004.
  • Furuya T, Kato D, Yamazaki S, et al. Microthymoma and microscopic thymomas associated with a thymic cyst without solid component. Gen Thorac Cardiovasc Surg 2018;66:303-6. doi: 10.1007/s11748-017-0808-7
  • Moran CA, Suster S. Mediastinal seminomas with prominent cystic changes. A clinicopathologic study of 10 cases. Am J Surg Pathol 1995;19:1047-53. doi: 10.1097/00000478-199509000-00008
  • Moran CA, Suster S, El-Naggar A, Luna MA. Carcinomas arising in multilocular thymic cysts of the neck: a clinicopathological study of three cases. Histopathology 2004;44:64-8. doi: 10.1111/j.1365-2559.2004.01767.x.
  • Moran CA, Suster S, Silva EG. Low-grade serous carcinoma of the ovary metastatic to the anterior mediastinum simulating multilocular thymic cysts: a clinicopathologic and immunohistochemical study of 3 cases. Am J Surg Pathol 2005;29:496-9. doi: 10.1097/01.pas.0000155147.37800.e1.
  • Shen X, Jin Y, Shen L, Sun Y, Chen H, Li Y. Thymoma and thymic carcinoma associated with multilocular thymic cyst: a clinicopathologic analysis of 18 cases. Diagn Pathol 2018;13:41. doi: 10.1186/s13000-018-0719-7.
  • Kondo K, Miyoshi T, Sakiyama S, Shimosato Y, Monden Y. Multilocular thymic cyst associated with Sjögren's syndrome. Ann Thorac Surg 2001;72:1367-9. doi: 10.1016/s0003-4975(00] 02706-5.
  • Gorospe L, García-Villanueva MJ, García-Cosío-Piqueras M, García-Gómez-Muriel I. Multilocular thymic cyst in a patient with Sjögren syndrome. Rheumatology (Oxford] 2019;58:369. doi: 10.1093/rheumatology/key221.
  • Matsumoto S, Mori Y, Takiya H, Iwata H, Shirahashi K. Multilocular thymic cyst associated with rheumatoid arthritis. Kyobu Geka 2012;65:205-8.