Mesenchymal chondrosarcoma (MCS) is a malignant cancer of the cartilage that accounts for less than 1% of all chondrosarcomas and typically occurs within the bone. One-third of all mesenchymal chondrosarcomas are extraosseous soft tissue sarcomas, rendering this as an uncommon entity. We report a rare case of an extraosseous chondrosarcoma with the cervical spinal canal in a 21-year-old male. The purpose of this case report is to discuss the imaging characteristics of this pathology proven diagnosis.

Medulloblastoma is the most common posterior fossa tumor of childhood typically within the fourth ventricle. However, extra-axial medulloblastoma in posterior fossa is an uncommon diagnosis. We report a case in a 33-month-old male who presented with repeated complaints of abdominal pain, intermittent emesis, and diarrhea, and diagnosed with right cerebellar extra-axial medulloblastoma, which was surgically resected. Majority of the reported extra-axial medulloblastoma in posterior fossa in the United States are located in the cerebellopontine angle. However, to the best of our knowledge, our case is the first to document medulloblastoma occurring exclusively in the cerebellar hemispheric extra-axial space rather than the cerebellopontine angle. Although the diagnosis can present as a radiological dilemma, a systematic multimodality imaging approach can aid in narrowing the differential diagnosis and timely management. In this case report, we will discuss the imaging characteristics, differential diagnosis, and management strategies, alongside a brief review of the world literature of extra-axial medulloblastoma.