Mickey Mouse Sign on Bone Scan

Abstract An 81-year-old man with prostate adenocarcinoma demonstrated interval progression of the osteoblastic metastatic disease on surveillant bone scan with a new lumbar lesion resembling the configuration of Mickey's head (Mickey Mouse sign), a sign considered to be specific for Paget disease, even in the presence of malignancy. However, our case demonstrates that this appearance can be caused by other etiologies. In the era of SPECT/CT and MRI, it is prudent to obtain further cross-sectional correlation at the time of radionuclide bone scintigraphy to clarify the underlying cause for “Mickey Mouse sign” to prevent misinterpretation, allowing for efficient and accurate patientcare.