Endocrine Abstracts

Introduction: Primary hyperparathyroidism (P-HPT) is a common endocrine disorder that occurs as result of adenomas (80–85%), hyperplasia (10–15%), atypical adenoma or carcinomas (<1%). Atypical parathyroid adenoma (APA) is a rare entity and represents intermediate group of parathyroid neoplasms of uncertain malignant potential with some atypical histological features.

Case details: We report a case of a 34-year male, with a background of hypertension (HTN) & chronic kidney disease (CKD), who was urgently referred by the GP to our hospital in view of alarmingly raised Calcium (Ca) & Parathyroid hormone (PTH). Clinical history revealed vague symptoms of ongoing lethargy. Bloods PTH 146 pmol/l (1.6–6.9), adjusted Ca 3.56 mmol/l (2.2–2.6). He was treated in the day unit with intravenous (IV) fluids and referred to our team who arranged for urgent admission as his calcium levels remained refractory to the mentioned intervention. Investigations revealed Vitamin D<20 nmol/l (>50), Alkaline Phosphatase (ALP) 66 IU/l (30–130), e-GFR 58 (>90). MEN workup including MR pituitary was normal.

Management: The patient initially recieved fluids following which intravenous(IV) Bisphosphonate was administered that dropped the Calcium to <3 over the next 48 h. He was arranged to have an urgent Sestamibi Nuclear Medicine Scan(NM SPECT CT) that revealed a 4.3 cm×6.5 cm×6.7 cm retrothyroidal mass in right lower neck with significant mass effect, displacing the thyroid and carotid sheath. Following this, he was urgently referred to the Surgical Team to have surgical intervention. Histopathology of the tissue samples revealed likely to be parathyroid adenoma with atypical features, most of which pursue a benign clinical course. Post operatively, Calcium has remained stable within normal limits on the follow up bloods since then. He is planned for Long term follow up in addition to regular clinical and radiological surveillance for features of malignancy or development of overt symptoms of MEN.

Discussion: Mutations in the CDC73 and HRPT2 gene are found in cases of parathyroid Carcinoma. In approximately one-third of affected individuals with changes in these genes, the mutation is inherited from a parent and is present in all of the body’s cells. On the other hand, no specific Imunohistochemical signature has been identified for APA, thus rendering the diagnosis much more challenging. Patients with APA at diagnosis have a clinical and biochemical pattern much more severe than its benign counterpart, thus warranting the need for Urgent Medical and Surgical attention, followed by a long-term Management plan with MDT input.