C91.12
BillableChronic lymphocytic leukemia of B-cell type in relapse
HCC Category Mapping
V28HCC 22 — Colorectal, Bladder, and Other Cancers
0.000V24HCC 10 — Lymphoma and Other Cancers
0.675ESRDHCC 10 — Lymphoma and Other Cancers
0.000RxHCCHCC 19 — Lymphoma and Other Cancers
0.000What This Code Means
A type of blood cancer (chronic lymphocytic leukemia) that started in B-cells and has returned after initial treatment.
Coding Tips
- •The fifth character '2' indicates relapse status - ensure documentation clearly states the cancer has returned after remission
- •This code is specific to B-cell type CLL; verify cell type is documented before coding
Clinical Significance
Chronic lymphocytic leukemia of B-cell type in relapse indicates that a previously treated and remission-achieving CLL has returned with detectable disease activity. Relapsed CLL often requires a change in treatment strategy and may indicate development of resistance to prior therapy. Relapsed disease frequently behaves more aggressively and may carry adverse cytogenetic changes acquired during treatment.
Documentation Requirements
- ✓Documentation must confirm both a prior period of remission and current evidence of disease recurrence, including rising lymphocyte counts, progressive lymphadenopathy, or bone marrow re-infiltration.
- ✓The date of relapse, interval since last remission, and prior treatment regimens should be documented.
- ✓Updated cytogenetic and molecular testing (including TP53 mutation and del(17p) status) should be noted.
Commonly Confused Codes
C91.10 (B-CLL not in remission) is used for active disease that never achieved remission or for initial diagnosis. C91.11 (B-CLL in remission) applies when disease is controlled. Refractory CLL (disease progressing during treatment without ever achieving remission) should be coded as C91.10, not C91.C91.Z2 (other lymphoid leukemia in relapse) is a less specific alternative.
Code Hierarchy
└C91Lymphoid leukemia└C91.1Chronic lymphocytic leukemia of B-cell type└C91.12Chronic lymphocytic leukemia of B-cell type in relapse
└C91.12Chronic lymphocytic leukemia of B-cell type in relapse