Metaplastic Thymoma

**Semantic type:** Neoplastic Process

**Definition:** A rare type of well circumscribed or encapsulated thymoma with a biphasic architecture, consisting of epithelial cell islands and bundles of spindle cells. The vast majority of reported cases had a benign clinical course.

**Synonyms:** - Biphasic Thymoma - Low Grade Thymic Metaplastic Carcinoma - Mixed Polygonal and Spindle Cell Type Thymoma - Thymoma with Pseudosarcomatous Stroma