Objective — the study objective was to improve the quality of detection of medulloblastoma metastases. Material and methods. Magnetic resonance imaging (MRI) of the spinal cord in a child with medulloblastoma of the posterior cranial fossa, which was performed on the first day after surgery, detected contrast-positive thickenings of the meninges in the cervical, thoracic, and lumbar spinal cord that might be erroneously diagnosed as metastasis. These lesions spontaneously regressed within 3 weeks, which was verified by control MRI. Conclusion. In the case of misinterpretation of a MRI picture of contrast-positive thickenings of the meninges, a patient is erroneously regarded as having tumor metastases and is subject to more intensive treatment. However, the lesions spontaneously disappear or greatly reduce after 2—3 weeks. The article presents a case of this phenomenon, describes the putative mechanisms of its development, and provides recommendations for its differential diagnosis from metastases.