Neoplasm of uncertain behavior of brain, supratentorial

This code signifies a brain tumor located above the tentorium cerebelli (supratentorial region) where the pathologist cannot definitively determine if it is benign or malignant based on current microscopic examination. This diagnosis is typically made after a biopsy or surgical resection, indicating an uncertain biological potential.

Apply this code when pathology reports describe a supratentorial brain lesion as a "neoplasm of uncertain behavior," "atypical neoplasm," or similar terminology indicating an indeterminate malignancy. Documentation must clearly specify the supratentorial location within the brain.

• Ensure the pathology report explicitly states "uncertain behavior" and the supratentorial location.
• Do not use this code if the tumor is definitively diagnosed as benign (e.g., meningioma) or malignant (e.g., glioblastoma).
• Remember the Excludes1 note: never code this with D43.1 (neoplasm of uncertain behavior of fourth ventricle).