In the last twenty years, we submitted 853 patients to thyroid surgery. We found only in ten patients a hyalinizing trabecular adenoma at the (histological control), as a confirmation of the rarity of this tumour. The authors report a retrospective analysis of this cases to document the clinical features and the evolution through a long term follow-up that has showed no recurrent disease. In conclusion the hyalinizing trabecular adenoma represents a low malignant potential tumour. However, the uncertain clinical behaviour doesn’t be undervalued and patients must be subjected to accurate follow-up.