C91.4Non-Billable (Header)Hairy cell leukemiaChild CodesC91.40Hairy cell leukemia not having achieved remissionHCC 22C91.41Hairy cell leukemia, in remissionHCC 22C91.42Hairy cell leukemia, in relapseHCC 22Code Hierarchy└C91Lymphoid leukemia└C91.4Hairy cell leukemia└C91.4Hairy cell leukemia