J Endocr Surg.  2022 Dec;22(4):116-122. 10.16956/jes.2022.22.4.116.

Clinical Characteristics of the Hyalinizing Trabecular Tumor

• Kim BC
• Pak SJ
• Cho JW
• Kim WW
• Lee Ym
• Sung TY
• Baek JH
• Chung KW

• KMID: 2538525
• DOI: http://doi.org/10.16956/jes.2022.22.4.116

Abstract

Purpose
Hyalinizing trabecular tumors (HTTs) are rare tumors of the thyroid gland. They are benign and of follicular origin. However, they are difficult to diagnose and can be misdiagnosed as a malignant thyroid tumor. The aim of this study was to clarify the clinical and radiological characteristics of HTT.
Methods
We retrospectively reviewed 7 patients who had been diagnosed with HTT postoperatively at the Asan Medical Center between May 2002 and May 2022. Ultrasonographic findings, including size, echogenicity, shape, and margin orientation, were investigated. Preoperative and intraoperative histological features were compared with the final pathological diagnoses.
Results
The median size of HTT was 26 mm. Total thyroidectomy and lobectomy were performed in 2 (28.6%) and 5 (66.6%) patients, respectively. Ultrasonography showed hypoechogenicity in 43% of patients and marked hypoechogenicity in 43% of patients. An ill-defined margin was present in 57% of patients. All tumors were parallel in shape, with non-spongiform components. All tumors had intermediate suspicious features according to the Korean Thyroid Imaging Reporting and Data System. The preoperative diagnosis of most patients was papillary thyroid carcinoma. Intraoperative frozen biopsy confirmed the preoperative diagnosis of medullary thyroid carcinoma in 1 patient. No recurrence or death occurred during a median follow-up of 100 months.
Conclusion
HTT is a rare benign tumor. Ultrasonographic findings of HTT resemble those of malignant thyroid tumors. Fine-needle aspiration cytology and intraoperative frozen biopsy are ineffective in diagnosing HTT. Under suspicion of HTT, total thyroidectomy should be avoided because of the indolent biological behavior of HTT.

Keyword

Hyalinizing trabecular tumor; Ultrasonography; Fine-needle aspiration