Epithelial-rich thymoma; Epithelial thymoma; Squamoid thymoma; Well-differentiated thymic carcinoma; WHO type B3 thymoma
Atypical thymoma is defined as a moderately differentiated thymic epithelial neoplasm that retains some of the organotypical features of differentiation of the thymus combined with mild to moderate cytologic atypia. These tumors are roughly equivalent to the type B3 thymoma in the WHO classification schema. The tumors are composed of round to polygonal or oval to spindle-shaped epithelial cells with scattered immature lymphocytes.
Atypical thymomas are a tumor of adults occurring between the ages of 14 and 78 with an average age of 45–50 years; as of yet, no discernible sex predilection has been observed. Like other thymic tumors, patients tend to present either asymptomatically or with symptoms related to mass effect of the tumor on adjacent mediastinal structures, such as chest pain, cough, or dyspnea. Rarely, these tumors have been associated...
References and Further Reading
- Travis, W. D., Brambilla, E., Burke A. P., Marx A., & Nicholson A. G. (Eds.). (2015). WHO classification of tumours of the lung, pleura, thymus and heart. Lyon: IARC Press 4th ed.Google Scholar