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Pathology of mediastinal tumors

INTRODUCTION

Mediastinal tumors are among the most difficult lesions examined by the surgical pathologist for several reasons. First, many different types of lesions occur in this location (figure 1 and figure 2). Second, biopsies often consist of small, crushed specimens. Third, few pathologists have significant experience with mediastinal pathology because specimens from this location are relatively uncommon.

Since many tumors that occur in the mediastinum are undifferentiated and have overlapping histologic features, one must consider a broad differential diagnosis and perform a thorough evaluation of each biopsy specimen. This is particularly important since appropriate therapy for various mediastinal tumors differs considerably and may significantly impact survival. Additionally, it may not be apparent whether the tumor actually arises in the mediastinum or from adjacent lung.

The pathology of mediastinal tumors is reviewed here. The clinical evaluation of mediastinal masses is discussed elsewhere, and clinical and management issues of the specific tumor types are reviewed in the relevant topics. (See "Evaluation of mediastinal masses".)

EXAMINATION OF SPECIMENS

One of the most difficult problems in the diagnosis of mediastinal tumors can be obtaining an adequate biopsy specimen. As some mediastinal tumors are not treated surgically (eg, lymphoma), diagnosis is often attempted with needle core or minimally invasive surgical biopsies. Biopsies may be non-diagnostic because the lesion is not sampled adequately or because crush artifact or extensive necrosis, fibrosis, or cystic change obscures the diagnostic lesion. (See "Evaluation of mediastinal masses".)

Intraoperative frozen sections are often used in the setting of surgical procedures:

                       

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Literature review current through: Jun 2014. | This topic last updated: Oct 28, 2013.
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References
Top
  1. Jüttner FM, Fellbaum C, Popper H, et al. Pitfalls in intraoperative frozen section histology of mediastinal neoplasms. Eur J Cardiothorac Surg 1990; 4:584.
  2. Pathology & genetics: Tumours of the lung, pleura, thymus and heart. In: World Health Organization Classification of tumours, Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (Eds), IARC Press, Lyon, France 2004.
  3. Surgical Pathology of the Mediastinum, 2nd, Raven Press, New York 1992.
  4. Pathology of the Thymus and Mediastinum, 1st, WB Saunders, Philadelphia 1995.
  5. Moran CA, Suster S, Fishback NF, Koss MN. Primary intrapulmonary thymoma. A clinicopathologic and immunohistochemical study of eight cases. Am J Surg Pathol 1995; 19:304.
  6. Moran CA, Travis WD, Rosado-de-Christenson M, et al. Thymomas presenting as pleural tumors. Report of eight cases. Am J Surg Pathol 1992; 16:138.
  7. Moran CA, Suster S, Koss MN. Plasma cell-rich thymoma. Am J Clin Pathol 1994; 102:199.
  8. Moran CA, Koss MN. Rhabdomyomatous thymoma. Am J Surg Pathol 1993; 17:633.
  9. Lewis JE, Wick MR, Scheithauer BW, et al. Thymoma. A clinicopathologic review. Cancer 1987; 60:2727.
  10. Marino M, Müller-Hermelink HK. Thymoma and thymic carcinoma. Relation of thymoma epithelial cells to the cortical and medullary differentiation of thymus. Virchows Arch A Pathol Anat Histopathol 1985; 407:119.
  11. Kirchner T, Schalke B, Marx A, Müller-Hermelink HK. Evaluation of prognostic features in thymic epithelial tumors. Thymus 1989; 14:195.
  12. Suster S, Moran CA. Thymoma, atypical thymoma, and thymic carcinoma. A novel conceptual approach to the classification of thymic epithelial neoplasms. Am J Clin Pathol 1999; 111:826.
  13. Chen G, Marx A, Chen WH, et al. New WHO histologic classification predicts prognosis of thymic epithelial tumors: a clinicopathologic study of 200 thymoma cases from China. Cancer 2002; 95:420.
  14. Chalabreysse L, Roy P, Cordier JF, et al. Correlation of the WHO schema for the classification of thymic epithelial neoplasms with prognosis: a retrospective study of 90 tumors. Am J Surg Pathol 2002; 26:1605.
  15. Kodama T, Watanabe S, Sato Y, et al. An immunohistochemical study of thymic epithelial tumors. I. Epithelial component. Am J Surg Pathol 1986; 10:26.
  16. Chan JK, Tsang WY, Seneviratne S, Pau MY. The MIC2 antibody 013. Practical application for the study of thymic epithelial tumors. Am J Surg Pathol 1995; 19:1115.
  17. Sato Y, Watanabe S, Mukai K, et al. An immunohistochemical study of thymic epithelial tumors. II. Lymphoid component. Am J Surg Pathol 1986; 10:862.
  18. Koga K, Matsuno Y, Noguchi M, et al. A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma. Pathol Int 1994; 44:359.
  19. Kornstein MJ, Curran WJ Jr, Turrisi AT 3rd, Brooks JJ. Cortical versus medullary thymomas: a useful morphologic distinction? Hum Pathol 1988; 19:1335.
  20. Quintanilla-Martinez L, Wilkins EW Jr, Choi N, et al. Thymoma. Histologic subclassification is an independent prognostic factor. Cancer 1994; 74:606.
  21. Shimosato Y. Controversies surrounding the subclassification of thymoma. Cancer 1994; 74:542.
  22. Suster S, Moran CA. Thymoma classification: current status and future trends. Am J Clin Pathol 2006; 125:542.
  23. Masaoka A, Monden Y, Nakahara K, Tanioka T. Follow-up study of thymomas with special reference to their clinical stages. Cancer 1981; 48:2485.
  24. Levine GD, Rosai J. Thymic hyperplasia and neoplasia: a review of current concepts. Hum Pathol 1978; 9:495.
  25. Suster S, Moran CA. Primary thymic epithelial neoplasms showing combined features of thymoma and thymic carcinoma. A clinicopathologic study of 22 cases. Am J Surg Pathol 1996; 20:1469.
  26. Suster S, Rosai J. Thymic carcinoma. A clinicopathologic study of 60 cases. Cancer 1991; 67:1025.
  27. Kirchner T, Schalke B, Buchwald J, et al. Well-differentiated thymic carcinoma. An organotypical low-grade carcinoma with relationship to cortical thymoma. Am J Surg Pathol 1992; 16:1153.
  28. Truong LD, Mody DR, Cagle PT, et al. Thymic carcinoma. A clinicopathologic study of 13 cases. Am J Surg Pathol 1990; 14:151.
  29. Moran CA, Suster S. Mucoepidermoid carcinomas of the thymus. A clinicopathologic study of six cases. Am J Surg Pathol 1995; 19:826.
  30. Iezzoni JC, Gaffey MJ, Weiss LM. The role of Epstein-Barr virus in lymphoepithelioma-like carcinomas. Am J Clin Pathol 1995; 103:308.
  31. Leyvraz S, Henle W, Chahinian AP, et al. Association of Epstein-Barr virus with thymic carcinoma. N Engl J Med 1985; 312:1296.
  32. Shimosato Y, Mukai K. Tumors of the Mediastinum, 3rd, Armed Forces Institute of Pathology, Washington, DC 1995.
  33. Shimosato Y, Kameya T, Nagai K, Suemasu K. Squamous cell carcinoma of the thymus. An analysis of eight cases. Am J Surg Pathol 1977; 1:109.
  34. Snover DC, Levine GD, Rosai J. Thymic carcinoma. Five distinctive histological variants. Am J Surg Pathol 1982; 6:451.
  35. Suster S, Moran CA. Primary synovial sarcomas of the mediastinum: a clinicopathologic, immunohistochemical, and ultrastructural study of 15 cases. Am J Surg Pathol 2005; 29:569.
  36. Hasserjian RP, Klimstra DS, Rosai J. Carcinoma of the thymus with clear-cell features. Report of eight cases and review of the literature. Am J Surg Pathol 1995; 19:835.
  37. Matsuno Y, Morozumi N, Hirohashi S, et al. Papillary carcinoma of the thymus: report of four cases of a new microscopic type of thymic carcinoma. Am J Surg Pathol 1998; 22:873.
  38. Choi WW, Lui YH, Lau WH, et al. Adenocarcinoma of the thymus: report of two cases, including a previously undescribed mucinous subtype. Am J Surg Pathol 2003; 27:124.
  39. Takahashi F, Tsuta K, Matsuno Y, et al. Adenocarcinoma of the thymus: mucinous subtype. Hum Pathol 2005; 36:219.
  40. Suster S. Thymic carcinoma: update of current diagnostic criteria and histologic types. Semin Diagn Pathol 2005; 22:198.
  41. Falconieri G, Moran CA, Pizzolitto S, et al. Intrathoracic rhabdoid carcinoma: a clinicopathological, immunohistochemical, and ultrastructural study of 6 cases. Ann Diagn Pathol 2005; 9:279.
  42. Lee AC, Kwong YI, Fu KH, et al. Disseminated mediastinal carcinoma with chromosomal translocation (15;19). A distinctive clinicopathologic syndrome. Cancer 1993; 72:2273.
  43. French CA, Kutok JL, Faquin WC, et al. Midline carcinoma of children and young adults with NUT rearrangement. J Clin Oncol 2004; 22:4135.
  44. Berezowski K, Grimes MM, Gal A, Kornstein MJ. CD5 immunoreactivity of epithelial cells in thymic carcinoma and CASTLE using paraffin-embedded tissue. Am J Clin Pathol 1996; 106:483.
  45. Fukai I, Masaoka A, Hashimoto T, et al. Cytokeratins in normal thymus and thymic epithelial tumors. Cancer 1993; 71:99.
  46. Fukai I, Masaoka A, Hashimoto T, et al. Differential diagnosis of thymic carcinoma and lung carcinoma with the use of antibodies to cytokeratins. J Thorac Cardiovasc Surg 1995; 110:1670.
  47. Hishima T, Fukayama M, Fujisawa M, et al. CD5 expression in thymic carcinoma. Am J Pathol 1994; 145:268.
  48. Dorfman DM, Shahsafaei A, Chan JK. Thymic carcinomas, but not thymomas and carcinomas of other sites, show CD5 immunoreactivity. Am J Surg Pathol 1997; 21:936.
  49. Ritter JH, Wick MR. Primary carcinomas of the thymus gland. Semin Diagn Pathol 1999; 16:18.
  50. Hino N, Kondo K, Miyoshi T, et al. High frequency of p53 protein expression in thymic carcinoma but not in thymoma. Br J Cancer 1997; 76:1361.
  51. Kuo TT, Chang JP, Lin FJ, et al. Thymic carcinomas: histopathological varieties and immunohistochemical study. Am J Surg Pathol 1990; 14:24.
  52. Rosai J, Higa E. Mediastinal endocrine neoplasm, of probable thymic origin, related to carcinoid tumor. Clinicopathologic study of 8 cases. Cancer 1972; 29:1061.
  53. Marx A, Shimosato Y, Kuo TT, et al. Thymic neuroendocrine tumours. In: Pathology & genetics: Tumours of the lung, pleura, thymus and heart, Travis WD, Brambilla E, Muller-Hermelink HK, Harris CC (Eds), IARC Press, Lyon, France 2004.
  54. Wick MR, Carney JA, Bernatz PE, Brown LR. Primary mediastinal carcinoid tumors. Am J Surg Pathol 1982; 6:195.
  55. Luna MA, Valenzuela-Tamariz J. Germ-cell tumors of the mediastinum, postmortem findings. Am J Clin Pathol 1976; 65:450.
  56. Weidner N. Germ-cell tumors of the mediastinum. Semin Diagn Pathol 1999; 16:42.
  57. Dulmet EM, Macchiarini P, Suc B, Verley JM. Germ cell tumors of the mediastinum. A 30-year experience. Cancer 1993; 72:1894.
  58. Childs WJ, Goldstraw P, Nicholls JE, et al. Primary malignant mediastinal germ cell tumours: improved prognosis with platinum-based chemotherapy and surgery. Br J Cancer 1993; 67:1098.
  59. Dehner LP. Germ cell tumors of the mediastinum. Semin Diagn Pathol 1990; 7:266.
  60. Knapp RH, Hurt RD, Payne WS, et al. Malignant germ cell tumors of the mediastinum. J Thorac Cardiovasc Surg 1985; 89:82.
  61. Moran CA, Suster S. Primary germ cell tumors of the mediastinum: I. Analysis of 322 cases with special emphasis on teratomatous lesions and a proposal for histopathologic classification and clinical staging. Cancer 1997; 80:681.
  62. Atlas of Tumor Pathology: Extragonadal Teratomas, 2nd, Armed Forces Institute of Pathology, Washington, DC 1982.
  63. Moran CA, Suster S, Przygodzki RM, Koss MN. Primary germ cell tumors of the mediastinum: II. Mediastinal seminomas--a clinicopathologic and immunohistochemical study of 120 cases. Cancer 1997; 80:691.
  64. Burns BF, McCaughey WT. Unusual thymic seminomas. Arch Pathol Lab Med 1986; 110:539.
  65. Schantz A, Sewall W, Castleman B. Mediastinal germinoma. A study of 21 cases with an excellent prognosis. Cancer 1972; 30:1189.
  66. Aygun C, Slawson RG, Bajaj K, Salazar OM. Primary mediastinal seminoma. Urology 1984; 23:109.
  67. Moran CA, Suster S. Mediastinal seminomas with prominent cystic changes. A clinicopathologic study of 10 cases. Am J Surg Pathol 1995; 19:1047.
  68. Iczkowski KA, Butler SL, Shanks JH, et al. Trials of new germ cell immunohistochemical stains in 93 extragonadal and metastatic germ cell tumors. Hum Pathol 2008; 39:275.
  69. Moran CA, Suster S, Koss MN. Primary germ cell tumors of the mediastinum: III. Yolk sac tumor, embryonal carcinoma, choriocarcinoma, and combined nonteratomatous germ cell tumors of the mediastinum--a clinicopathologic and immunohistochemical study of 64 cases. Cancer 1997; 80:699.
  70. Saxman S, Nichols CR, Williams SD, et al. Mediastinal yolk sac tumor. The Indiana University experience, 1976 to 1988. J Thorac Cardiovasc Surg 1991; 102:913.
  71. Ulbright TM, Roth LM, Brodhecker CA. Yolk sac differentiation in germ cell tumors. A morphologic study of 50 cases with emphasis on hepatic, enteric, and parietal yolk sac features. Am J Surg Pathol 1986; 10:151.
  72. Moran CA, Suster S. Hepatoid yolk sac tumors of the mediastinum: a clinicopathologic and immunohistochemical study of four cases. Am J Surg Pathol 1997; 21:1210.
  73. Moran CA, Suster S. Primary mediastinal choriocarcinomas: a clinicopathologic and immunohistochemical study of eight cases. Am J Surg Pathol 1997; 21:1007.
  74. Marchevsky AM. Mediastinal tumors of peripheral nervous system origin. Semin Diagn Pathol 1999; 16:65.