Metastatic Ectopic Thymoma of the Neck without Mediastinal Involvement

Document Type : Case Report

Authors

1 Department of Radiation Oncology, Government Medical College and Hospital Chandigarh, Chandigarh, India.

2 Department of ENT & Head and Neck Surgery, Government Medical College and Hospital Chandigarh, Chandigarh, India.

Abstract

Introduction:
Thymoma is a rare malignancy with usual location in the antero-superior mediastinum. Occurrence of an extra-mediastinal thymic malignancy in the neck with lung metastasis and without involvement of the mediastinum is an extremely rare condition. Staging systems and treatment guidelines are defined for mediastinal thymomas but not for ectopically located thymomas.
Case Report:
38-year-old female presented with the chief complaint of a progressive neck swelling, located predominantly in the right lateral neck, extending to the midline. Computed Tomography showed a heterogenous peripherally enhancing mass with likely origin from the thyroid gland. The mass measured 12 x 6 x 3.5 cm in size and extended from the hyoid bone superiorly to the suprasternal location inferiorly. Additionally, there were multiple, variable sized subpleural nodules scattered in both lungs, suggestive of lung metastases. Histopathology and immunohistochemistry findings from neck mass confirmed the diagnosis of Thymoma Type A. 
Conclusions:
Thymoma is a rare tumor that typically does not show aggressive behaviour. Extra-mediastinal neck thymoma with bilateral lung metastasis is an extremely rare presentation. Thymoma presenting as neck swelling without mediastinal extension on radiology, poses a diagnostic dilemma. Histopathology with immunohistochemistry helps to confirm the final diagnosis. Surgery is the mainstay for the management of localized tumors with adjuvant treatment reserved for incompletely resected tumors or advanced stage. Systemic metastasis are rare in this indolent tumor and chemotherapy regimens are investigational. Clinical presentation, prognostic factors, staging and management guidelines are still not well defined for this rare tumor with atypical location.

Keywords

References

  1. Mullen B, Richardson JD. Primary anterior mediastinal tumors in children and adults. Ann Thorac Surg. 1986;42(3):338-345.
  2. Lewis JE, Wick MR, Scheithauer BW, Bernatz PE, Taylor WF. Thymoma. A clinicopathologic review. Cancer. 1987;60(11):2727–2743.
  3. Regnard JF,          Fourquier P, Levasseur P. Results and prognostic factors in resections of primary tracheal tumors: a multicenter retrospectivestudy. The French Society of Cardiovascular Surgery. J Thorac Cardiovasc Surg. 1996;111(4):808–813.
  4. Maggi G, Casadio C, Cavallo A, Cianci R, Molinatti M, Ruffini E. Thymoma: results of 241 operated cases. Ann Thorac Surg. 1991;51(1):
    152–156.
  5. Pan CC, Wu HP, Yang CF, Chen WY, Chiang H. The clinicopathological correlation of epithelial subtyping in thymoma: a study of 112 consecutive cases. Hum Pathol. 1994;25(9):893–899.
  6. Okumura M, Miyoshi S, Takeuchi Y, Yoon HE, Minami M, Takeda SI, et al. Results of surgical treatment of thymomas with special reference to the involved organs. J Thorac Cardiovasc Surg. 1999; 117(3):605–613.
  7. Nakahara K, Ohno K, Hashimoto J, Maeda H, Miyoshi S, Sakurai M, et al. Thymoma: results with complete resection and adjuvant postoperative irradiation in 141 consecutive patients. J Thorac Cardiovas Surg. 1988;95(6):1041–1047.
  8. Engels EA. Epidemiology of thymoma and associated malignancies. J Thorac Oncol. 2010; 5(10 Suppl 4):S260–65.
  9. Wu X, Guo J, Zhou X, Li Y, Huang Y, Wu L. Ectopic thymoma: report of 2 cases and review of the literature. Int J Clin Exp Pathol. 2019; 12(12): 4297-4302.
  10. Hino H, Nitadori JI, Ohno K, Kishimoto S, Takahashi M, Kakizaki M, et al. An Unusual Invasive Ectopic Thymoma in the Thyroid and Anterior Mediastinum. Ann Thorac Surg. 2018; 106: e65-e67.
  11. Zhu H, Lei Y, Zou J, Su C, Zeng B, Li Y, et al. Ectopic right parietal pleural thymic carcinoma: a rare case and review of the literature. J Thorac Dis. 2017;9(7):E609-E613.
  12. Wu SL, Gupta D, Connelly J. Adult Ectopic Thymus Adjacent to Thyroid and Parathyroid. Arch Pathol Lab Med. 2001;125(6):842–843.
  13. Bale PM, Sotelo-Avila C. Maldescent of the thymus: 34 necropsy and 10 surgical cases, including 7 thymuses medial to the mandible. Pediatr Pathol. 1993;13(2):181–190.
  14. Embryology, pathology, and clinical implications. Am J Surg. 1978;136(5):631–637.
  15. Halperin EC, Wazer DE, Perez CA, Brady LW. Perez & Brady’s Principles of Radiation Oncology. 7th ed. Philadelphia:Wolters Kluwer; 2018. p.
    3666-70.
  16. Chan JK, Rosai J. Tumors of the neck showing thymic or related branchial pouch differentiation: a unifying concept. Hum Pathol. 1991;22(4):349-67.
  17. Pearse G. Histopathology of the thymus. Toxicol Pathol. 2006;34(5):515-47.
  18. Alexiev BA, Drachenberg CB, Burke AP. Thymomas: a cytological and immunohistochemical study, with emphasis on lymphoid and neuroendocrine markers. Diagn Pathol. 2007;2:13.
  19. Weissferdt A, Moran CA. Immuno- histochemistry in the diagnosis of thymic epithelial neoplasms. Appl Immunohistochem Mol Morphol. 2014; 22(7):479-87.
  20. Miyamoto K, Acoba JD. Thymomas and Thymic carcinomas: A review on pathology, presentation, staging, treatment and novel systemic therapies. EMJ Respir. 2017;5(1):100-107.
  21. Singhal S, Shrager JB, Rosenthal DI, LiVolsi VA, Kaiser LR. Comparison of stages I-II thymoma treated by complete resection with or without adjuvant radiation. Ann Thorac Surg. 2003; 76(5): 1635-41.
  22. Kondo K, Monden Y. Therapy for thymic epithelial tumors: a clinical study of 1,320 patients from Japan. Ann Thorac Surg. 2003;76(3):878-84.
  23. Moser B, Fadel E, Fabre D, Keshavjee S, de Perrot M, Thomas P, et al. Surgical therapy of thymic tumours with pleural involvement: an ESTS Thymic Working Group Project. Eur J Cardiothorac Surg. 2017;52(2):346-55.
  24. Safieddine N, Liu G, Cuningham K, Ming T, Hwang D, Brade A, et al. Prognostic factors for cure, recurrence and long-term survival after surgical resection of thymoma. J Thorac Oncol. 2014; 9(7): 1018-22.
  25. Forquer JA, Rong N, Fakiris AJ, Loehrer PJ, Johnstone PA. Postoperative radiotherapy after surgical resection of thymoma: differing roles in localized and regional disease. Int J Radiat Oncol Biol Phys. 2010;76(2):440-5.
  26. Shin DM, Walsh GL, Komaki R, Putnam JB, Nesbitt J, Ro JY, et al. A multidisciplinary approach to therapy for unresectable malignant thymoma. Ann Intern Med. 1998;129(2):100-4.
  27. Loehrer PJ, Kim K, Aisner SC, Livingston R, Einhorn LH, Johnson D, et al. Cisplatin plus doxorubicin plus cyclophosphamide in metastatic or recurrent thymoma: final results of an intergroup trial. The Eastern Cooperative Oncology Group, Southwest Oncology Group, and Southeastern Cancer Study Group. J Clin Oncol. 1994; 12(6): 1164-8.
  28. Giaccone G, Ardizzoni A, Kirkpatrick A, Clerico M, Sahmoud T, van Zandwijk N. Cisplatin and etoposide combination chemotherapy for locally advanced or metastatic thymoma. A phase II study of the European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group. J Clin Oncol. 1996;14(3):814-20.

 

  1. Fukui T, Fukumoto K, Okasaka T, Kawaguchi K, Nakamura S, Hakiri S, et al. Prognostic impact of tumour size in completely resected thymic epithelial tumours. Eur J Cardiothorac Surg. 2016;50(6):
    1068-74.
  2. Venuta F, Rendina EA, Pescarmona EO, De Giacomo T, Vegna ML, Fazi P, et al. Multimodality treatment of thymoma: a prospective study. Ann Thorac Surg. 1997;64(6):1585-91.
  3. Cowen D, Richaud P, Mornex F, Bachelot T, Jung GM, Mirabel X, et al. Thymoma: results of a multicentric retrospective series of 149 non-metastatic irradiated patients and review of the literature. FNCLCC trialists. Fédération Nationale des Centres de Lutte Contre le Cancer. Radiother Oncol. 1995;34(1):9-16.
  4. Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages. Cancer. 1981;48(11):
    2485-92.
  5. Pollack A, Komaki R, Cox JD, Ro JY, Oswald MJ, Shin DM, et al. Thymoma: treatment and prognosis. Int J Radiat Oncol Biol Phys. 1992; 23(5):1037-43.
Iranian Journal of Otorhinolaryngology
Volume 34, Issue 5
September and October 2022
Pages 257-263

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