label: Thyroid Gland Spindle Epithelial Tumor with Thymus-Like Elements
label_lc: thyroid gland spindle epithelial tumor with thymus-like elements
description: "A rare, slow growing malignant tumor of the thyroid gland arising from intrathyroidal thymic tissue. It is characterized by a lobulated architectural pattern and the presence of a biphasic cellular population composed of spindle epithelial cells and glandular cells.  A small number of cases are composed exclusively of spindle epithelial cells or glandular cells."