Multiple Osteolytic Lesions With a "Superscan" on Bone Scintigraphy as the Presenting Manifestation of a Parathyroid Adenoma in a 29-Year-Old Woman: A Case Report

Overt osteitis fibrosa cystica is an uncommon presentation of primary hyperparathyroidism (PHPT) in young adults.A 29-year-old woman presented with low back pain of one year's duration.Lumbar computed tomography (CT) showed multiple osteolytic lesions, and bone scintigraphy showed a metabolic "superscan".Biochemistry showed the following: parathyroid hormone (PTH) 1807.3 pg/mL, hypercalcemia (3.06 mmol/L), hypophosphatemia, alkaline phosphatase 1489 U/L, and severe vitamin D deficiency.Ultrasound and dualphase sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) localized a single left inferior parathyroid lesion.Parathyroidectomy yielded an encapsulated adenoma (~5.9 g) without capsular or vascular invasion.PTH fell to 30.9 pg/mL on day 1 but rose to 310.3 pg/mL by day 64, while calcium remained mildly low (2.03 mmol/L), consistent with compensatory skeletal remineralization and vitamin D deficiency rather than proven residual disease.A neuropsychiatric event at 13 months was of uncertain relationship to PHPT.