Fine-Needle Aspiration Cytologic Diagnosis of Intrathyroidal Thymic Carcinoma: A Review of the Literature.

Intrathyroidal thymic carcinoma is a rare thyroid carcinoma characterized by thymic epithelial differentiation. Given its relatively favorable prognosis, it is essential to differentiate it preoperatively from other more aggressive tumors. Fine-needle aspiration is widely used for the preoperative diagnosis of thyroid nodules. However, there is limited information on the cytological diagnosis, and its cytomorphological features remain poorly characterized. We perform a literature review of intrathyroidal thymic carcinoma and briefly describe two cases to further characterize its cytological features.