Endocrine Abstracts

Background: Parathyroid Carcinoma (PC) is a very rare endocrine malignancy. Unlike Parathyroid Adenoma (PA) and Parathyroid Hyperplasia which represents 80% and 15-20% cases of primary hyperparathyroidism (PHPT) respectively, PC only constitutes 1-2% of cases. Herein we present a clinical case of PC following a low-impact trauma.

Clinical case: A 50-year-old Bulgarian female presented with a pathological mid-shaft fracture of her right femur following a trivial trip over her shoe laces when walking in the street. Initial biochemical values are remarkable for adjusted serum calcium of 3.22 mmol/l, Alkaline phosphatase (ALP) of 280 IU/l, urea of 18.4 mmol/l and creatinine of 182 μmol/l. Further blood tests revealed a significant parathyroid hormone level of 1997 ng/l. A subsequent computerised tomography scan of chest, abdomen and pelvis discovered no focal parenchymal abnormality but expansile right sided rib metastases with widespread lytic lesions of the pelvic bones. An incompletely imaged density in the left supraclavicular fossa may represent a thyroid mass. An urgent ultrasound of the neck was followed which showed a very large (2.1x2.3x4.3cm) ectopic left inferior parathyroid gland with clearly defined margins. A bone biopsy obtained at the same time as her right femur intramedullary nail intervention was sent and revealed a brown tumour of hyperparathyroidism with no evidence of atypia or malignancy. She underwent left inferior parathyroidectomy from which tissue sample was obtained. Histological studies discovered PC with extensive adjacent lymphovascular invasion. Both local and external Multi-disciplinary team (MDT) discussions have agreed to proceed with left hemithyroidectomy and neck dissection to ensure complete removal of microscopic disease.

Conclusions: As PC is very rare and has many overlapping features with other common causes of PHPT, confirming the diagnosis pre-operatively is challenging. A thorough MDT involvement is also important in providing safe and effective care for the patient.