benign neoplasm of brain stem (Monarch Disease Ontology identifier MONDO_0021507) is a benign neoplasm that involves the brainstem. Also known as: benign brain stem neoplasm, benign brain stem neoplasms, benign brain stem tumor, benign brain stem tumour, benign brainstem neoplasm, benign brainstem neoplasms, benign brainstem tumor, benign brainstem tumors.