cerebellomedullary cistern

cer·e·bel·lo·med·ul·lar·y cis·tern

[TA] the largest of the subarachnoid cisterns between the cerebellum and the medulla oblongata; it is divided into a posterior cerebellomedullary cistern [TA] located between the cerebellum and the posterior surface of the medulla (also called cisterna magna), and a lateral cerebellomedullary cistern [TA] located between the cerebellum and the lateral aspect of the medulla.