Introduction: Hyalinizing trabecular adenomas (HTA) of the thyroid is an unusual disorder. HTA can be present as a thyroid nodule or incidental finding in a thyroidectomy specimen. Most behave as benign neoplasms, but their cytological features can be similar to those of papillary thyroid carcinoma.
Case report: A 68 year old woman admitted to our institution with a solitary thyroid nodüle. Her serum free thyroxine (fT4), free triiodothyronine (fT3) and TSH levels are 1.03 ng/dl, 2.79 pg/ml, and 0.364 μIU/ml. Ultrasonography of the thyroid gland showed a 1.7 cm sized, regularly marginated, hypoechoic, calcified thyroid nodüle. Fine needle aspiration biopsy of the thyroid nodule revealed suspicious for papillary carcinoma (PTC). Thyroid scan is showed a cold thyroid nodule in the right lobe. Total thyroidectomy were perfomed. The final pathology was 1.1 cm sized hyalinizing trabecular adenoma. Histologically, the tumor showed tumor cells arranged in trabeculae and a prominent hyaline stroma. The neoplastic cells were focally immunoreactive for thyroglobulin and negative for calcitonin and chromogranin. After surgery L-thyroxine replacement therapy was started. Two years after thyroidectomy, the patient is alive and free of disease.
Conclusion: Ultrasonografic features of HTA similar to malign thyroid lesions and frequently misdiagnosed as papillary carcinoma on fine-niddle aspiration cytology. The most recent and controversial debate surrounding HTA concerns its potentially malignant behavior and the possible relationship to PTC. Although cases of malignant HTT have been recorded, HTT should be considered a benign neoplasm or, at most, a neoplasm of extremely low malignant potential. In this report we present and discuss an unusual case of a patient who had a hyalinizing trabecular adenoma.
30 Apr - 04 May 2011
European Society of Endocrinology