Increased muscle uptake is commonly seen with 18 F-FDG PET/ CT because of an important physiological muscle glucose metabolism. Muscle uptake can express a recent significant muscle activity. However, the absence of muscle uptake is almost never described or interpreted. We describe the case of an 8-year-old boy with extrarenal rhabdoid tumor in the right carotid space. An MRI and an 18 F-FDG PET/CT were performed for the diagnostic workup. There was no uptake in the lateral rectus oculomotor muscle unlike all other oculomotor muscles. The ophthalmological examination found a diplopia confirmed by the Lancaster test.