Bone Abstracts

Background: Primary hyperparathyroidism (PH), whilst common in elderly populations, is much rarer in adolescents. Although up to 90% of cases are sporadic in nature, hereditary cases make up less than 10% of remaining causes. Multiple genetic causes and syndromes have been described in the literature including multiple endocrine neoplasia (MEN), familial hypocalciuric hypercalcemia and hyperparathyroidism-jaw tumour syndrome (HPT-JT).

Presenting problem: A 14-year-old girl with a past history of depression, chronic constipation, bony pains and self-harm was admitted from a Tier 4 CAMHS (Children and Adolescent Mental Health Service) unit following an overdose of fluoxetine. Investigations revealed hypercalcemia (adjusted calcium 3.66mmol/L), hypophosphatemia, vitamin D insufficiency and significantly elevated PTH at 82.9pmol/L (range 1.1–6.9 pmol/L) with increased urinary calcium excretion.

Clinical management: She was initially managed with intravenous fluids and furosemide. Due to persistent hypercalcemia, she was subsequently treated with bisphosphonates, cinacalcet and calcitonin. Her vitamin D levels where supplemented. Ultrasound and sestamibi scan revealed an enlarged parathyroid mass adjacent to the left upper pole of the thyroid gland. Pituitary function was normal as were x-rays of her hand, spine and ultrasound of her renal tract. The parathyroid adenoma was removed surgically. She was hypocalcaemic in the immediate post-operative period requiring calcium supplements. Her PTH levels normalised post surgery and improvement in her psychiatric symptoms was observed. Molecular genetic testing revealed a heterozygous mutation of CDC73. There was no significant family history, although her mother and sister will be screened.

Discussion: Psychiatirc symptoms including depression and self-harm are reconginsed features of hypercalcemia, particularly in patients with primary hyperparathyroidism. In these situations, some or all of their presenting symptoms can reflect parathyroid pathology not psychiatric. Baseline screening should be considered, including bone profile, to rule out organic pathology. Particularly in cases needing inpatient psychiatric admission or in patients with other symptoms suggestive of underlying calcium disorder. Mutations in CDC73 are associated with HPT-JT syndrome. It can lead to parathyroid tumours and ossified lesions of the jaw, renal tract and uterus. Early detection is important in surveillance and treatment of complications in addition to allowing genetic counselling for patients and family.

Disclosure: The authors declared no competing interests.