[Pathology] Atlas of Thymic Epithelial Neoplasms (part 4), Thymic Epithelial Neoplasms, Atlas of Mediastinal Pathology
Fig. 2.40 The stromal component in spindle-cell thymoma with
pseudosarcomatous stroma is characterized by a bland population of spindle
cells devoid of any signifi cant cytologic atypia, nuclear pleomorphism,
or mitotic activity that often adopts a fascicular or storiform pattern
Fig. 2.41 Micronodular thymoma corresponds to an unusual variant of
spindle-cell thymoma characterized by a distinct nodular growth pattern with
dense lymphoid stroma. Unlike the lymphoid stroma in conventional thymomas,
the small lymphocytes in these tumors are composed of reactive,
polyclonal B cells rather than immature T cells
Fig. 2.42 Higher magnification of micronodular spindle-cell thymoma
with B-cell hyperplasia shows nodules of varying sizes composed of
oval to spindle cells with abundant eosinophilic cytoplasm. The stroma
surrounding the nodules is densely packed with a polyclonal population
of B lymphocytes admixed with plasma cells
Fig. 2.43 Higher magnification in micronodular spindle-cell thymoma
shows an island of epithelial cells characterized by oval to spindle
nuclei without significant cytologic atypia and devoid of mitotic activity. The cells are indistinguishable from those of conventional spindlecell thymoma and are
positive for cytokeratin, p63, and PAX8
Fig. 2.44 Micronodular spindle-cell thymoma can also contain
scattered hyperplastic lymphoid follicles with reactive germinal centers
(center). Rare cases of lymphoma arising from micronodular thymoma
have been described
Fig. 2.45 Invasive spindle-cell thymoma shows infiltration of perithymic
fat by tumor with through-and-through penetration of the capsule.
Spindle-cell thymomas are also capable of invasion of surrounding
structures and metastases and can be associated with aggressive
behavior in a small percentage of cases (~10 %). In such cases, prognosis is
dictated by the staging of the tumor independent of the histology
Fig. 2.46 Liver metastasis of spindle-cell thymoma discovered at
autopsy in a 54-year-old woman who died as a result of widespread
metastases from an invasive spindle-cell thymoma
Suggested Reading
Chalabreysse L, Roy P, Cordier J-F, Loire R, Gamondes JP, ThivoletBejui F. 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;26:1605–11.
Choi WWL, Lui YH, Lau WH, Crowley P, Khan A, Chan JK. Adenocarcinoma of the thymus: report of two cases, including a previously undescribed mucinous subtype. Am J Surg Pathol. 2003;27:124–30.
Hasserjian RP, Klimstra DS, Rosai J. Carcinoma of the thymus with clear cell features: report of eight cases and a review of the literature. Am J Surg Pathol. 1995;19:835–41.
Kalhor N, Suster S, Moran CA. Spindle cell thymoma with prominent papillary and pseudopapillary features: A clinicopathologic study of 10 cases. Am J Surg Pathol. 2011;35:372–7.
Koga K, Matsuno Y, Noguchi M, Mukai K, Asamura H, Goya T, Shimosato Y. A review of 79 thymomas: modification of staging system and reappraisal of conventional division into invasive and non-invasive thymoma. Pathol Int. 1994;44:359–67.
Matsuno Y, Morozumi N, Hirosashi S, Shimosato Y, Rosai J. Papillary carcinoma of the thymus. Report of four cases of a new microscopic type of thymic carcinoma. Am J Surg Pathol. 1998;22:873–80.
Moran CA, Suster S. Mucoepidermoid carcinomas of the thymus. Clinicopathologic study of 6 cases. Am J Surg Pathol. 1995;19:826–34.
Moran CA, Suster S. Thymoma with prominent cystic and hemorrhagic changes and areas of necrosis and infarction. A clinicopathologic study of 25 cases. Am J Surg Pathol. 2001;25:1086–90.
Moran CA, Suster S. Ancient (sclerosing) thymomas. A clinicopathologic study of 10 cases. Am J Clin Pathol. 2004;121:867–71.
Moran CA, Suster S. Thymic carcinoma: current concepts and histologic features. Hematol Oncol Clin North Am. 2008;22:393–407.
Moran CA, Kalhor N, Suster S. Invasive spindle cell thymomas (WHO type A): a clinicopathologic correlation of 41 cases. Am J Clin Pathol. 2010;134:793–8.
Pan CC, Chen WY, Chiang H. Spindle cell and mixed spindle/lymphocytic thymomas: an integrated clinicopathologic and immunohistochemical study of 81 cases. Am J Surg Pathol. 2001;25:111–20.
Rieker RJ, Hoegel J, Morresi-Hauf A, Hofmann WJ, Blaeker H, Penzel R, Otto HF. Histologic classification of thymic epithelial tumors: comparison of established classifications schemes. Int J Cancer. 2002;98:900–6.
Shimosato Y, Kameya T, Nagai K, Suemasu K. Squamous cell carcinoma of the thymus: an analysis of 8 cases. Am J Surg Pathol. 1997;1:109–21.
Snover DC, Levine GD, Rosai J. Thymic carcinoma: five distinctive histological variants. Am J Surg Pathol. 1982;6:451–70.
Suster S, Rosai J. Thymic carcinoma: a clinicopathologic study of 60 cases. Cancer. 1991;67:1025–32.
Suster S, Rosai J. Cystic thymomas: clinicopathologic study of 10 cases. Cancer. 1992;69:92–7.
Suster S, Moran CA. Primary thymic epithelial neoplasms with combined features of thymoma and thymic carcinoma. A clinicopathologic study of 22 cases. Am J Surg Pathol. 1996;20:1469–80.
Suster S, Moran CA, Chan JKC. Thymoma with pseudosarcomatous stroma. Report of an unusual histologic variant of thymic epithelial neoplasms that may simulate carcinosarcoma. Am J Surg Pathol. 1997;21:1316–23.
Suster S, Moran CA. Thymic carcinoma: spectrum of differentiation and histologic types. Pathology. 1998;30:111–22.
Suster S, Moran CA. Thymoma, atypical thymoma and thymic carcinoma. A novel conceptual approach to the classifi cation of neoplasms of thymic epithelium. Am J Clin Pathol. 1999a;111:826–33.
Suster S, Moran CA. Spindle cell carcinoma of the thymus. Clinicopathologic and immunohistochemical study of 15 cases of a novel form of thymic carcinoma. Am J Surg Pathol. 1999b;23:691–700.
Suster S, Moran CA. Micronodular thymoma with lymphoid B-cell hyperplasia. Clinicopathologic and immunohistochemical study of 18 cases of a distinctive morphologic variant of thymic epithelial
neoplasm. Am J Surg Pathol. 1999c;23:955–62.
Suster S, Moran CA. Primary thymic epithelial neoplasms: spectrum of differentiation and histologic features. Semin Diagn Pathol. 1999d;16:2–17.
Suster S. Thymic carcinoma: update of current diagnostic criteria and histologic types. Semin Diagn Pathol. 2005;22:198–212.
Suster S, Moran CA. Thymoma classification: current status and future trends. Am J Clin Pathol. 2006;125:542–54.
Suster S, Moran CA. Classification of thymoma: the WHO and beyond. Hematol Oncol Clin North Am. 2008;22:381–92.
Suster S, Moran CA. The mediastinum. In: Weidner N, Cote R, Suster S, Weiss LM, editors. Modern surgical pathology. 2nd ed. Philadelphia: W.B. Saunders; 2009. p. 454–516.
Travis WD, Brambilla E, Burke AP, Marx A, Nicholson AG. Pathology and genetics. Tumors of the lung, pleura, thymus, and heart. In: World Health Organization classification of tumors. Lyon: IARC
Press; 2015.
Wu T-C, Kuo T-T. Study of Epstein-Barr virus RNA (EBER-1) expression by in-situ hybridization in thymic epithelial tumors of Chinese patients in Taiwan. Hum Pathol. 1993;24:235–8.
This is only a part of the book : Atlas of Mediastinal Pathology of authors: Saul Suster. If you want to view the full content of the book and support author. Please buy it here: https://www.amazon.com/Atlas-Mediastinal-Pathology-Anatomic/dp/149392673X
COMMENTS