Poster Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

As clear as mud: an atypical case of primary hyperparathyroidism (#234)

Jessica Lai 1 2 3 , Navin Niles 1 3 4 , Namson Lau 1 3 5
  1. South Western Clinical School, University of New South Wales, Sydney
  2. Westmead Hospital, Westmead, NSW, Australia
  3. Liverpool Hospital, Liverpool, NSW
  4. Macquarie University Hospital, Macquarie Park, NSW
  5. LIVEDIAB CRU, Ingham Institute, University of New South Wales, Sydney

Objective: A young woman presented with marked hyperparathyroidism with post-operative course complicated by hungry bone syndrome and diagnostic and management challenges of ongoing hypocalcaemia with hyperparathyroidism.

 

Method: ML, a 32-year-old Fijian Indian female, was referred with severe hypercalcaemia, following one-year history of migratory debilitating bone pain.  Initial labs showed corrected calcium(C.Ca) 3.17 [2.10-2.60mmol/L], parathyroid hormone(PTH) 305.4 [2.0-6.0pmol/L] and 25-hydroxyvitamin D(25-VitD) of 22 [40 – 80nmol/L]. Acute management included admission for intravenous fluids and bisphosphonates, which normalised C.Ca. A parathyroid SESTAMIBI/CT-SPECT demonstrated a 31x9x33mm soft tissue mass in anterior superior mediastinum with focal uptake at T3. Further CT neck demonstrated 10x5x5mm mass between left common carotid and subclavian arteries.

 

Results: ML’s surgical resection of the mediastinal mass was immediately complicated by generalised bony pain, pleural effusions and despite aggressive replacement of calcium, marked hypocalcaemia (Day 1 C.Ca 1.99); consistent with an exaggerated “hungry bone syndrome”. ML has been followed closely for on-going optimisation of calcium and vitamin D; three-month labs showed elevated PTH (30.7pmol/L), despite normalisation of 25-VitD (79nmol/L) and improved C.Ca (2.04mmol/L). Her pre-operative DEXA scan showed T-scores: lumbar spine -5.1SD and bilateral femoral necks -5.6SD. A MRI cervical spine demonstrated widespread lytic lesions including, a lesion in the C2 spinous process and posterior pedicles, considered consistent with pathological fracture. Histopathology reported a 70x65x51mm; 41gm mass with no invasive features. Parafibromin was positive, whilst PGP9.5 was negative; other patterns of staining were normal, making HRPT2/CDC73 mutation unlikely.

 

Conclusion: This case highlights: 1) the diagnostic challenge of marked hyperparathyroidism with a clinical picture suggestive of malignancy, but histological evidence not supporting invasion; 2) the management issues of moderating post-operative severe hypocalcaemia and hungry bone phenomenon; and 3) the on-going diagnostic and management of post-operative hyperparathyroidism with hypocalcaemia. In summary, atypical primary hyperparathyroidism presents unique diagnostic and management challenges.