Mixed squamous cell carcinoma and follicular carcinoma of the thyroid gland

Primary squamous cell carcinoma of the thyroid gland (PSCCT) is rare [1], [2], [3]; different theories on its aetiology do exist [4], [5], [6]. Mixed squamous cell and follicular carcinoma is even more rare than pure squamous cell of the thyroid gland and only few cases are reported in literature [7]. Preoperative diagnosis can be very challenging and the differential diagnosis with secondary squamous cell carcinoma of the thyroid (SSCCT) is manadatory in order to plan a correct management of the disease. The presence of PSCCT with distant metastasis of follicular carcinoma supports the histogenesis of squamous cell carcinomas arising from follicular epithelial cells.