APPEARANCE OF HÜRTHLE CELL CARCINOMA SOON AFTER SURGICAL EXTIRPATION OF HÜRTHLE CELL ADENOMA AND FOLLICULAR ADENOMA OF THE THYROID GLAND -case report-
Background: Hürthle cell neoplasms (HCN) could be benign (Hürthle cell adenoma - HCA) or malignant (Hürthle cell carcinoma - HCC). HCC are rare tumors, representing 5% of all differentiated thyroid carcinomas. The cytological evaluation of HCN by FNAB is complicated because of the presence of Hürthle cells in both HCA and HCC. Thus, the preoperative distinction between these two entities is very difficult and possible only with pathohistological findings of the removed tumors.
Case report: A 57-year old female patient was admitted at our Department, for investigation of nodular thyroid gland. She was euthyroid and FNAB of the nodules in both thyroid lobes were consistent of HCA with cellular atypias. After thyroidectomy the histopathology revealed HCA with high cellular content and discrete cellular atypias in the left lobe and follicular thyroid adenoma without cellular atypias in the right lobe. One year after substitution therapy, a palpable tumor on the left side of the remnant tissue was found, significantly growing with time, presented as hot nodule on MIBI scan and conclusive with HCA with marked cellularity on FNAB. Tumorectomy was performed and well-differentiated HCC detected. The patient received ablative dose of 100mCi 131I. No signs of metastatic disease are present up to date.
Conclusion: The differences between HCAs and HCCs could be clearly made only by histopathological evaluation. Patients with cytological diagnosis of HCNs should proceed to total thyroidectomy, especially if tumor size is >1cm, FNAB findings comprise cellular atypias and/or multiple bilateral nodules are detected in the thyroid gland.