Hyalinizing trabecular tumor of thyroid (HTT) – A rare case report

Hyalinizing Trabecular Tumour of the Thyroid (HTT) is a rare type of tumor that affects the thyroid gland. It was first discovered by Carney in 1987. This tumor is of follicular origin and has unique nuclear, architectural, and immunohistochemical features that differentiate it from other well-known thyroid abnormalities, such as Papillary Thyroid Carcinoma (PTC) and Medullary Thyroid Carcinoma (MTC). Although initially thought to be a subtype of PTC, several later reports showed that HTT is an independent entity. The incident rate of HTT ranges between 0.44% and 1.3%. This case report presents a 46-year-old male patient who complained of swelling in the front of his neck, more towards the left side, which had been observed for the past three months. FNAC (fine needle aspiration cytology) reported it as a follicular lesion of undetermined significance - Bethesda category III. Hemithyroidectomy was performed on the patient, and HTT was diagnosed through histopathological examination. As it is a benign neoplasm, PTC or other tumors had to be ruled out, and management varied accordingly. Based on its biological and clinical behavior, HTT should be considered as a benign neoplasm or as a neoplasm of extremely low malignant potential. This case report is presented for its unusual occurrence and unique behavior