Normocalcemic primary hyperparathyroidism: 99mTc SestaMibi SPECT/CT results compare with hypercalcemic hyperparathyroidism.

Context: Normocalcemic primary hyperparathyroidism (nPHPT) is defined by an inappropriately increased serum PTH with normal serum calcium. Information about the diagnostic yield of parathyroid SPECT/CT scan and ultrasonography in nHPPT is limited and not conclusive.

Purpose: To evaluate the positivity rate of Tc-Sestamibi SPECT/CT scan in nPHTP compared with classical hypercalcemic PHPT (cPHPT).