Endocrine Abstracts

A 60-year-old South African male, presented as an emergency with a 4 week history of lethargy, polyuria, increased thirst, constipation and weight loss. Blood tests revealed hypercalcemia with CCa-4.72 mmol/l, PTH-159.3pmol/l and 25 OH Vitamin D 22mmol/l. Intensive iv hydration was followed by IV Pamidronate 60 mg stat. Calcitonin (4 units/Kg tds) was started 48 hours later which resulted in a fall in the calcium to 2.66 by day 5. Cinacalcet 30 mg od was then introduced such that normocalcaemia was achieved by day 14. Interestingly admission CBG readings were in the range 10-18. The concurrent HbA1c was normal at 40mmol/mol. Amylase was normal. A basal bolus regimen of insulin was started. As the calcium lowered, so did his insulin requirement such that he was discharged on Metformin & Linagliptin. Intracellular hypercalcaemia decreases normal insulin-stimulated glucose transport, thereby increasing insulin requirements. A 4D-CTparathyroid with contrast demonstrated a heterogenous left parathyroid nodule close to subclavian with focal calcification raising suspicion of parathyroid carcinoma. He had an uneventful left parathyroidectomy and the initial histology report suggested a benign left parathyroid adenoma. Due to clinical concern, a second opinion from a regional head and neck centre was requested. The expert histopathologist characterised this as Parathyroid tumour of uncertain malignant potential PTUMP (otherwise known as atypical adenoma). This is a rare condition with incidence of 1-3% and requires close follow up. The histology sample has been sent to USA for further analysis. Eight weeks after surgery, calcium is normal at 2.25. The patient has stopped all anti diabetic medication. Blood glucose readings are within normal range. The HbA1c has fallen to 31. Atypical parathyroid adenomas represent a group of intermediate form of parathyroid neoplasms of uncertain malignant potential which show atypical histological features and lack evident signs of local invasion and/or metastasis.