Hyalinizing Trabecular Tumor in a Background of Lymphocytic Thyroiditis: A Challenging Neoplasm of the Thyroid

Abstract

To describe a case of hyalinizing trabecular tumor (HTT) in a background of lymphocytic thyroiditis that was misdiagnosed as papillary thyroid carcinoma (PTC) based on fine-needle aspiration (FNA) cytologic findings and overtreated with total thyroidectomy. We present a case report, including the imaging and pathologic findings, of a 68-year-old woman who presented with a multinodular goiter that was suspicious for PTC. On the basis of FNA cytologic findings, she underwent a total thyroidectomy, and histologic examination of the thyroid gland revealed HTT in a background of lymphocytic thyroiditis. Radioiodine treatment was not administered because of the tumor's low risk profile. No metastatic foci were established under nonsuppressive levothyroxine therapy after 3 years of follow-up. HTT is a challenging entity because of the uncertainty of its nature, the diagnostic challenges, and the mimicry of other types of thyroid tumors. In order to avoid overtreatment, endocrinologists and thyroid surgeons should be aware of the features of HTT, and suspicious cases should be evaluated by experienced cytopathologists.