Endocrine Abstracts

Introduction: Only <1% of cases of primary hyperparathyroidism (PHPT) occur during pregnancy. PHPT increases risk of complications such as miscarriage, premature birth and life-threatening maternal hypercalcemic crises. Hyperparathyroidism Jaw Tumor Syndrome (HPT-JT) is a rare inherited cause of PHPT, resulting from CDC73 gene mutations. There are a few reports described about HPT-JT in pregnancy. Although parathyroidectomy is the definite treatment for PHPT, given the scarce evidence on the management of PHPT in pregnancy, questions regarding its safety arise. Additionally, medical therapies such as bisphosphonates, cinacalcet or calcitonin are not recommended, as there is no proven safety.

Objective: We present the case of a woman with HPT-JT, who became pregnant while awaiting surgical treatment.

Clinical Case: A 19-year-old woman with a history of repeated miscarriages and urolithiasis was referred to an Endocrinology appointment due to hypercalcemia of 12.4 mg/dl (8.8-10.6). The remainder study revealed serum PTH of 950 pg/ml (9-72), phosphataemia of 2.2 mg/dl (2.9-5.0), 25-OH Vitamin D of 27 ng/ml (30-100) and normal urinary clearance calcium/creatinine ratio. Cervical ultrasound showed a right inferior parathyroid adenoma. The genetic study identified a CDC73 gene pathogenic variant, confirming the diagnosis of HPT-JT. The clinical situation was explained to the patient, namely the risks associated with pregnancy. Despite this, while awaiting surgical treatment, a 5-week pregnancy was diagnosed, in the context of an episode of abdominal pain. In this patient, we opted for close surveillance and conservative treatment with increased oral hydration and restriction of calcium in the diet, delaying surgery to the postpartum period. Pregnancy complications included: an episode of acute renal colic pain at week 10 of pregnancy, which was treated conservatively; a threatened preterm labor at week 28, that responded positively to bed rest. During pregnancy, calcemia values between 12.7-13.2 mg/dl and PTH between 678-882 pg/ml. Spontaneous vaginal delivery occurred at 39 weeks and 3 days, with a birth weight of 2920g. There were no evident changes in fetal development. Our patient currently awaits postpartum reassessment.

Conclusions: The fact that the patient had become pregnant prior to surgical treatment raised major approach challenges, given the rarity of the clinical situation, the risk of maternal-fetal adverse effects and the scarcity of therapeutic options in pregnancy. Although parathyroidectomy constitutes the definitive treatment for PHPT, the type of treatment during pregnancy is complex and must be individualized, taking into account additional factors such as the severity of hypercalcemia and the risk of post-surgical complications.