Multiple brown tumors in a patient with parathyroid adenoma depicting affinity for both [99m]Tc -pertechnetate and [99m]Tc-MIBI: Evaluation with hybrid SPECT/CT

Parathyroid adenoma involving a single parathyroid gland is the underlying cause of 80-85% of primary hyperparathyroidism [PHPT]. Skeletal system is significantly affected by PHPT. Brown tumors are known to have affinity for [99m]Tc-MIBI. We report a rare case of PHPT presenting with diffuse bony pain, high calcium level and significantly elevated alkaline phosphatase level. [99m]Tc-pertechnetate/[99m]Tc-MIBI subtraction, performed as a part of routine protocol, showed several brown tumors showing affinity for both [99m]Tc-pertechnetate and [99m]Tc-MIBI. They were further characterized using hybrid SPECT/CT. To the best of our knowledge, [99m]Tc-pertechnetate affinity in brown tumors has not been previously described