Case Report: Recurrent primary hyperparathyroidism during pregnancy in MEN1

N Patel, A Dietrich, M Stechman and D Scott-Coombes. Department Endocrine Surgery, University Hospital Wales, Cardiff and Vale University Health Board.

The Case: A 23-year-old female, mother of 1, with a 2-year history of lethargy, headaches and feeling of thirst was referred to the endocrinology outpatients by her GP with primary hyperparathyroidism (adjusted calcium 2.77 mmol/L with an inappropriately elevated PTH of 21.5 pmol/L). There was no family history of endocrine disease. Her 24 hr urinary calcium was normal. The patient underwent a targeted left inferior parathyroidectomy after concordant localisation studies (USS and Sestamibi scan). The ioPTH dropped by 70% at 10mins. The following day she remained hypercalcaemic A.Ca 2.67 mmol/L and PTH 6.2pmol/L. Histology showed an parathyroid adenoma weighing 610mg.

At 4 month follow up she was 9 weeks pregnant. Bone profile confirmed persistent primary hyperparathyroidism (Calcium 2.65 mmol/L and PTH 15.9 pmol/L). Prolactin was raised at 641 and IgF-1 was normal. She underwent genetic testing and was diagnosed to be an index case of MEN1.

A USS showed right superior 7mm elongated parathyroid gland behind the mid pole of the right thyroid lobe which was not evident on previous imaging.  Four months later in her 2nd trimester of pregnancy she underwent cervical exploration and subtotal parathyroidectomy and thymectomy. Interestingly, only 2 parathyroid tumours were found and no 4th gland was identified (right inferior) suggesting she may only have 3 glands. One and a half glands were excised. At 6 week follow up her PTH was 1.9pmol/L and her calcium was normal at 2.28mmol/.

Discussion points: MEN1 is associated with multi glandular disease and therefore targeted parathyroidectomy is contraindicated. As we did not know the MEN1 diagnosis we did perform a targeted approach and there was a false positive ioPTH outcome.

The increase risk of maternal and foetal complications associated with HPT in pregnancy meant an earlier re-exploration (in her pregnancy).

There was a potential failure to find the fourth parathyroid or she may only have had 3 glands. She remains in follow-up.