TY - JOUR
T1 - Atypical thymoma (epithelial-rich thymoma, well-differentiated thymic carcinoma, WHO type B3 thymoma)
T2 - A conundrum
AU - Weissferdt, Annikka
AU - Moran, Cesar A.
N1 - Publisher Copyright:
© 2023 Elsevier GmbH
PY - 2023/5
Y1 - 2023/5
N2 - Thymomas composed predominantly of epithelioid tumor cells with scattered lymphocytes have been well recognized in the literature. This subtype of thymoma has been variously termed epithelial-rich thymoma, well-differentiated thymic carcinoma, atypical thymoma, or World Health Organization (WHO) type B3 thymoma. Regardless of the designation however, these tumors are known to show a spectrum of histopathological growth patterns that may pose challenges in interpretation and diagnosis, particularly when dealing with small mediastinoscopic biopsies. Just like any other type of thymoma, those composed predominantly of epithelioid cells may present as encapsulated or invasive tumors. Nevertheless, compared to other subtypes of thymoma, they are uncommon neoplasms. Therefore, it becomes very important to sufficiently sample thymomas before making a diagnosis of a particular subtype, especially when the tumor is rich in epithelioid cells and only has a scant lymphocytic component. Because of the unusual occurrence of these tumors, there are only few large series of cases that attempt to highlight not only the more salient histopathological features but also the most important immunohistochemical and molecular characteristics.
AB - Thymomas composed predominantly of epithelioid tumor cells with scattered lymphocytes have been well recognized in the literature. This subtype of thymoma has been variously termed epithelial-rich thymoma, well-differentiated thymic carcinoma, atypical thymoma, or World Health Organization (WHO) type B3 thymoma. Regardless of the designation however, these tumors are known to show a spectrum of histopathological growth patterns that may pose challenges in interpretation and diagnosis, particularly when dealing with small mediastinoscopic biopsies. Just like any other type of thymoma, those composed predominantly of epithelioid cells may present as encapsulated or invasive tumors. Nevertheless, compared to other subtypes of thymoma, they are uncommon neoplasms. Therefore, it becomes very important to sufficiently sample thymomas before making a diagnosis of a particular subtype, especially when the tumor is rich in epithelioid cells and only has a scant lymphocytic component. Because of the unusual occurrence of these tumors, there are only few large series of cases that attempt to highlight not only the more salient histopathological features but also the most important immunohistochemical and molecular characteristics.
KW - Atypical thymoma
KW - Epithelial-rich thymoma
KW - Mediastinum
KW - Thymic carcinoma
KW - Thymoma
KW - Well differentiated thymic carcinoma
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U2 - 10.1016/j.prp.2023.154459
DO - 10.1016/j.prp.2023.154459
M3 - Review article
C2 - 37043966
AN - SCOPUS:85151841060
SN - 0344-0338
VL - 245
JO - Pathology Research and Practice
JF - Pathology Research and Practice
M1 - 154459
ER -