Cerebral venous thrombosis as the initial presentation of MEN1-associated primary hyperparathyroidism in early pregnancy

ABSTRACT

Primary hyperparathyroidism (PHPT) is rare in pregnancy, and its nonspecific symptoms often delay diagnosis. Uncontrolled hypercalcemia can lead to severe maternal and fetal complications, including thrombotic events. Here, we report a 33-year-old woman at 11 weeks of gestation who presented with headache and seizures. Magnetic resonance imaging revealed superior sagittal sinus thrombosis, and investigations showed hypercalcemia (12.6 mg/dL) with markedly elevated intact parathyroid hormone (PTH). Despite hydration, calcitonin and cinacalcet, hypercalcemia persisted, necessitating sustained low-efficiency dialysis followed by parathyroidectomy at 12 weeks. Histology confirmed parathyroid adenomas, and genetic testing identified a pathogenic multiple endocrine neoplasia-1 mutation (c.1252G>A, p.Asp418Asn). The patient remained eucalcemic post-surgery and delivered a healthy infant. This case report highlights that PTH-dependent hypercalcemia can precipitate cerebral venous thrombosis in pregnancy and emphasizes the importance of early recognition of PHPT in atypical thrombotic presentations, timely parathyroidectomy, and genetic evaluation in young patients with familial disease.