Carcinoma of the neck showing thymic-like elements (CASTLE): report of a case and review of the literature.

Carcinoma showing thymic-like elements (CASTLE) is a rare tumor affecting thyroid and neck soft tissues, which has to be distinguished from squamous cell and anaplastic thyroid carcinoma, because it has a better prognosis. We report a new case of CASTLE which occurred in a patient submitted to total thyroidectomy with central neck dissection. The tumor stained positively for CD5, which seems to be the most useful marker in the differential diagnosis. By the analysis of the 18 cases reported in literature, total thyroidectomy with selective modified neck dissection should be the treatment of choice and radiotherapy should be considered for patients with positive nodal status.