HÜRTHLE CELL CARCINOMA: A RARE CASE WITH UNIQUE MORPHOLOGICAL FEATURES

Hürthle cell carcinoma (HCC) of the thyroid is an unusual and relatively rare type of thyroid cancer. Small series of HCC patients have been reported in the literature, but because of its relative rarity, its pathological and clinical significance have not been well documented. A 55-year-old woman presented with rapid neck mass enlargement and hoarseness. Thorax X-ray imaging suggested intrathoracic struma. Ultrasonographic examination showed struma nodosa in the right lobe. Fine-needle aspiration biopsy results suggested a follicular neoplasm of Hürthle cell type. Grossly, the right thyroid size was 6 × 5 × 4 cm and was brown, firm, and encapsulated. The cut surfaces were brown and lobulated, with no papillary growth or calcification. A histological examination showed large tumor cells in a trabecular arrangement, rounded nuclei, coarse chromatin, some vesicular with prominent nucleoli, and abundant granular eosinophilic cytoplasm. Another section revealed capsular invasion, and a solid area containing scattered bizarre giant cells with irregular nuclei. The histopatological features and imunohistochemical staining results supported a diagnosis of encapsulated angioinvasive HCC with bizarre nuclei. HCC is a rare type of carcinoma that remains controversial and difficult to diagnose. Careful assessment should be performed to look for bizarre nuclei to prevent overdiagnosis.