[Rare thyroid tumors: spindle-cell epithelial tumor and thyroid carcinoma with thymus-like differentiation].

The paper describes 2 cases of spindle-cell epithelial thyroid tumors (SETTLE) and carcinoma showing thymus-like differentiation (CASTLE). They are rare types of thyroid tumors and must be distinguished from medullary carcinoma, anaplastic carcinoma, synovial sarcoma and malignant teratoma. The presented cases show both common and unusual features as compared with the previously described tumors. CASTLE probably arises from ectopic thymus tissue. The further examination is needed to highlight the histogenesis of SETTLE, and to collect additional data on its aggressiveness and clinical outcome.