Code for the behavior of the tumor being reported using ICD-O-3. NAACCR adopted ICD-O-3 as the standard coding system for tumors diagnosed beginning January 1, 2001, and later recommended that prior cases be converted from ICD-O-2. See Behavior (92-00) ICD-O-2 [430], for ICD-O-2 codes.
Juvenile astrocytoma is coded as borderline in ICD-O-3; North American registries report as 9421/3.
Valid codes are 0-3. See ICD-O-3,14 page 66, for behavior codes and definitions.