A sixty-year-old woman suffering from difficulty in respiration and painful swelling in thyroid with gradually increase in the bulk for more than four months referred to our center.
She was a known case of hypertension and her blood pressure was under control. She did not have any past medical or family history of thyroid problems. She looked ill without any sign of ophtalmopathy. In thyroid examination, there was an asymmetrical hypertrophy (right lobe dominant), which was tense in palpation, tender and mobile on deglutition. Also central cervical lympha-denopathy was detected. Respiratory, cardiovascular and abdominal examinations were normal.
Laboratory tests included: Biochemistry and CBC tests which were in normal ranges; The TSH level increased to 20.58 mIU/L); and T3, T4 were in normal limit. In the next step, ultrasonography of thyroid gland was performed and revealed two hypoechoic nodules in the right lobe, one, M: 5*4.5*3.5 cm3 and another, M: 3*2.5*2.5 cm3. A 131-I thyroid scan revealed two cold nodules in the right lobe and the possibility of thyroiditis. The cytology of the fine needle aspiration (FNA) showed cellular smear containing microfollicular clusters populated by follicular cells with high N/C ratio, pleomorphic vesicular nuclei, prominent nucleoli, and abundant finely granulated eosinophilic cytoplasm with distinct cell borders. Some nuclear grooves were found. Background consisted of little colloid material and many lymphocytes in various stages of maturation. Therefore, diagnosis of Hürthle cell variant papillary carcinoma was considered. According to all above data, the patient underwent total thyroidectomy with central cervical lymph node dissection. During surgery severe adherence of thyroid gland to the neck muscles especially the right lobe was observed. The macroscopic examination of the right lobe showed two well-defined encapsulated nodules, one, M: 4.5*4*3.5 cm3 with mahogony soft to rubbery tissue cut surfaces. Another nodule was, M: 2.5*2*2 cm3 with granular soft tissue cut surfaces (Figure 1). The surrounding and the left lobe of thyroid gland on serial cutting revealed a rubbery meaty and lobulated appearance with the hemorrhagic foci.
Fig. 1. Cut surface of enlarged right lobe with two well defined encapsulated nodules, (big arrow and small arrow).
The histopathology examination of the larger encapsulated nodule showed a thickened encapsulated neoplasm in trabecular, solid and microfollicular growth pattern with the prominent loss of cell polarity. Individual neoplastic pleomorphic follicular cells were characterized by high nucleus/cytoplasm (N/C) ratio, vesicular to hyperchromatic nuclei, prominent nucleoli, deeply eosinophilic and granular glassy cytoplasm with distinct cell borders and Hürthle cells appearance. Capsular and vascular invasions were also found (Figures 2A, 2B, 2C).
In some areas, tumoral cells were merged with the surrounding bland looking thyroid follicles (invasion). The mitotic activity was seen. The smaller nodule revealed thyroid malignant infiltrative neoplasm in papillary structure growth pattern. Individual tumoral cells were characterized by high N/C ratio, ground glass nuclei with molding, groove and pseudo nuclear inclusion (Figure 2D). Background consisted of Hashimoto’s thyroiditis. In the central cervical lymph node dissection specimen, a regional lymph node was found involved by tumor, histologically.
The post-operative period was uneventful. She was referred to the oncology ward and received radioactive iodine therapy. During the follow up, a whole body I-131 Scan was done that revealed no evidence of regional lymph node or distant involvement. The patient was free of disease in the following 14 months. Before enrollment of the patient in this study, participant consent was obtained.
Fig. 2. A) Hürthle cell carcinoma and Classic type of papillary thyroid carcinoma separated by a thick capsule, (H&E X100), B) Tumoral Hürthle cells merged with surrounding bland looking thyroid follicles, (H&E X100), C) Hürthle cell carcinoma, (H&E X400), D) Classic type of papillary thyroid carcinoma, (H&E X200)