Multiple brown tumors in a patient with parathyroid adenoma depicting affinity for both 99mTc -pertechnetate and 99mTc-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 99mTc-MIBI. We report a rare case of PHPT presenting with diffuse bony pain, high calcium level and significantly elevated alkaline phosphatase level. 99mTc-pertechnetate/99mTc-MIBI subtraction, performed as a part of routine protocol, showed several brown tumors showing affinity for both 99mTc-pertechnetate and 99mTc-MIBI. They were further characterized using hybrid SPECT/CT. To the best of our knowledge, 99mTc-pertechnetate affinity in brown tumors has not been previously described.