Endocrine Abstracts

Background: Parathyroid cancer (PC) is a rare tumor associated with poor prognosis particularly when disseminated. Currently, the only effective treatment is a surgical intervention.

Case: Starting from the age of 19 a woman had been suffering from bone pains and change in gait. A low-energy right humerus fracture with displacement occurred when she was 23. At the same time, primary hyperparathyroidism (PHPT) was diagnosed for the first time (PTH 569 pg/ml (15–65), Ca total – 3.30 mmol/l (2.15–2.55)) and the right lower parathyroid gland (PG) was removed that led to a remission of the diseases. Histological examination showed PC. The first recurrence of PC with metastases in the neck lymph nodes developed in a year. The subtotal resection of the thyroid gland, a removal of pre- and paratracheal tissue, nerve-sparing lymphadenectomy on the right of the neck was performed with achievement of a remission of PHPT (PTH 4 pg/ml, Ca total 1.82 mmol/l). After 3 years (at the age of 29), there was a second recurrence of PC (Ca total 4 mmol/l, PTH 2 186 pg/ml) with metastases in S3 of the left lung (17 mm) and in the liver SII-III (17 × 17mm and 24 × 2.7 mm). A resection of the upper lobe of the left lung and liver resection (bisegmentectomy II -III with resection of the IV) was successfully performed in two stages. The metastases of PC verified by histological analysis and immunohistochemistry (IHC) of the removed distant lesions. The remission of the disease has been observed for the last two years (PTH 6 pg/ml, Ca total 2.08 mmol/l). Considering that the manifestation of the PHPT began at an early age and mothers’ PHPT (parathyroid adenoma) a hereditary form of PHPT was suspected. Next-generation sequencing identified a germline mutation in the CDC73 (c.355C>T:p.Q119X).

Conclusion: Patient with PC associated with a germline mutation in the CDC73 has a poorer disease prognosis. In some cases, it is possible to achieve a remission of the disease by a surgical removal of distant metastases, but future studies must focus on searching a new effective treatment option.