Evaluation of the Malignant Grade of Thymic Epithelial Tumors According to the Epithelial Subclassification

Thymic carcinoma: state of the art review

“…This classification allows reproducible definition of thymic carcinoma based on morphologic features, an important step toward standardization of nomenclature and taxonomy (51). A separate system, the Marino, Kirchner, and Muller-Hermlink system designates two malignant subtypes of thymic epithelial tumor based on histology, atypical type and cytologically malignant type, a well-differentiated and highgrade thymic carcinoma, respectively (52)(53)(54)(55)(56). Both the WHO and Muller-Hermlink systems demonstrate prognostic correlation (56 -57).…”

Synchronous Multicentric Thymona: Report of a Case

“…We performed an extended thymothymectomy. The tumor Reprint requests to: S. Yoneda Received: March 10, 2003 / Accepted: November 4, 2003 grade increasing from type A to C. 3 The World Health Organization clinical classification of thymic epithelial tumors 1 correlates well with that of Masaoka et al, 2 and it is possible that type B3 thymoma may be a transitional type from thymoma to thymic carcinoma. Based on the different immunohistochemical findings, the pathologist interpreted that multicentric thymoma occurred synchronously in one thymus in our patient.…”

Head and neck: Thymus: Thymoma: an overview

“…The grade of thymoma is another unsolved problem and a permanent subject of dispute. It was shown that thymoma without overt cytological atypia have better prognosis (Yoneda et al, 2000), but exceptions from this rule were also reported. The grading system largely accepted now is in fact a compromise: we have not a better one!…”