Hyalinizing trabecular tumor of the thyroid: Case report and review of the literature.

In 1987, Carney et al described a rare thyroid tumor termed hyalinizing trabecular adenoma presenting characteristics consisting of a trabecular growth pattern and hyalinizing stroma. In subsequent reports, the observed nuclear features and RET alterations led this tumor to be linked to papillary carcinoma. Subsequent reports concerning hyalinizing trabecular carcinoma further complicated its classification. To avoid uncertainties, the definition of hyalinizing trabecular tumor (HTT) is more widely used. Herein, a case of HTT is reported in detail, and the circumstances are also discussed. HTT is thought to be particularly differentiated from papillary carcinoma despite the identical high frequency of nuclear grooves and cytoplasmic inclusions, and MIB-1-positive staining is one of the most accurate diagnostic methods due to the distinct membrane-positive pattern noted in HTT. It is believed that most HTTs are benign and lobectomy is the standard treatment. Pathologists should offer surgeons information concerning diagnosis overlapping with effective treatment.