Endocrine Abstracts

The combination of thyroid and parathyroid carcinoma (PC) are extremely rare. We present a case with metastases of both tumors to the lymph nodes of the neck in a woman who received renal replacement therapy with long-term hemodialysis.

Case report

In 1984, when she was 24 years old, the patient began working at a nuclear power plant as a chemical water treatment operator. The total length of service was 25 years. In 2009 (at the age of 49) the patient presented decreased renal filtration (creatinine 110 µmol/l, GFR 51 ml/min/1.73 m²) as well as increased PTH (2500 pg/ml (15–65)) and total calcium (3.36 mmol/l (2.15–2.55)). In 2010, the left lower parathyroid gland (PG) was removed, and the left thyroid lobe resected. A histological examination revealed PC (рT2Nx). Immunohistochemical (IHC) examination revealed the PTH staining, the tumor cell nuclei was immunopositive for parafibromin; the Ki-67 proliferation index was 5%. Over the next 3 years, the PC was in remission. The hemodialysis therapy was started. After 12 months PC progression was diagnosed and a final thyroidectomy was performed along with total parathyroidectomy and central lymph node dissection using intraoperative navigation methods (single-channel gamma detection probe, Gamma Probe 2, and fluorescence angiography with indocyanine green (ICG). During the surgery, the lesion in the thyroid bed on the left showing significant uptake of the isotope (^99mTc-MIBI) and ICG was exposed. Microscopic examination showed a focus of PC in the fatty tissue, and two lymph nodes with subtotal metastases of papillary thyroid cancer (follicular variant). The morphological features of the PC are similar to the histological picture of the PC removed in 2010. IHC examination of the PC revealed diffuse expression of PTH and parafibromin. The Ki-67 proliferation index was 7%. This treatment led to achievement of laboratory targets: PTH 160 pg/ml, albumin-corrected calcium 2.53 mmol/l, Ca⁺⁺ 1.23 mmol/l. Ultrasound, CT with contrast, SPECT/CT, needle washing liquid PTH (more than 5000 pg/ml) demonstrated an ongoing relapse of the disease with multiple metastases of PC to the neck lymph nodes. However, the dimensions of the lesions are not ’target’ ones and, in view of the absence of uncontrolled hypercalcemia, follow-up was continued.

Conclusion

We believe it is important to publish different variants of PC and its combinations with other conditions in order to summarize available data and subsequently create clear recommendations for the prediction, treatment and monitoring in this complex group of patients.