ureter benign neoplasm (Monarch Disease Ontology identifier MONDO_0001398) is cancer or tumors of the ureter which may cause obstruction leading to hydroureter, hydronephrosis, and pyelonephritis. hematuria is a common symptom. Also known as: benign neoplasm of the ureter, benign neoplasm of ureter, benign tumor of the ureter, benign tumor of ureter, benign tumour of the ureter, benign tumour of ureter, benign ureter neoplasm, benign ureter tumor.