Correlative Imaging in Parathyroid Scintigraphy: A Tale of Two Synchronous Findings

Tc-99m methoxyisobutylisonitrile (MIBI) is the commonest radiopharmaceutical used for parathyroid scintigraphy (PS). Thyroid adenomas are a well-known cause of false-positive results, underscoring the importance of performing correlative thyroid ultrasound imaging in all patients. Tc-99m MIBI is taken up by a variety of tumors and meticulous scrutiny for uptake outside the normal tracer biodistribution may yield important diagnoses. The incidental detection of various tumors on Tc-99m MIBI PS have been reported. We describe a case of an occult de novo breast cancer found incidentally in a patient with a false-positive PS result.