Huerthle cell follicular carcinoma of the thyroid gland presenting with diffuse meningeal carcinomatosis and evolving to anaplastic carcinoma

摘要

Huerthle cell follicular carcinoma (HCFC) of the thyroid gland is a malignant tumour composed predominantly or entirely of oncocytes (also called "Hiirthle" or "Askenazy" cells), arranged in a follicular/trabecular pattern without the cytological changes found in papillary carcinoma. Although most studies have demonstrated that HCFC and follicular thyroid carcinoma share similar clinical behaviour and prognosis, recently the World Health Organization (WHO) has classified HCFC as a separate and distinct entity. Anaplastic thyroid carcinoma accounts for 5-10% of all thyroid cancers and represents the most aggressive thyroid tumour almost invariably associated with a fatal outcome. Most anaplastic thyroid carcinoma cases show evidence of a preexisting differentiated, or poorly differentiated, thyroid carcinoma. At present, to our knowledge, the secondary leptomeningeal localisation of thyroid HCFC has not yet been reported in the literature.