Thymic Carcinoma
Ming Guo, MD
Key Facts
Clinical Issues
High-grade malignancy with poor prognosis
Usual sites of metastases include lymph nodes, bone, lung, pleura, liver, and brain
Cytopathology
Presence of malignant cells with necrosis
Diagnosis of exclusion
Mature T cells and B cells
Ancillary Tests
Tumor cells positive for CD5, CD70, and CD117
Tumor cells negative for CD57
Top Differential Diagnoses
Atypical thymoma
World Health Organization type B3
Metastatic carcinoma of lung and other organs
 (A) Pap-stained smear shows thymic carcinoma cells without biphasic pattern of thymoma. (B) Pap-stained smear of thymic carcinoma, nonkeratinizing type, shows malignant features (i.e., variation in nuclear sizes  , irregular nuclear contour, and abnormal chromatin pattern). (C) Pap-stained smear shows thymic carcinoma with pleomorphic malignant cells  . (D) H&E-stained cell block section shows thymic carcinoma with predominantly nonkeratinizing cell type. |
TERMINOLOGY
Synonyms
World Health Organization (WHO) type C thymoma
Poorly differentiated (high-grade) thymic epithelial neoplasm
Definitions
Primary thymic epithelial neoplasm with clear cytologic features of malignancy and without thymic differentiation
CLINICAL ISSUES
Epidemiology
