C84.04
BillableMycosis fungoides, lymph nodes of axilla and upper limb
HCC Category Mapping
V28HCC 20 — Lung and Other Severe 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 rare type of skin cancer (mycosis fungoides) that has spread to the lymph nodes in the armpits and upper arms.
Coding Tips
- •Document axillary and upper limb lymph node involvement through physical exam or imaging
- •The '4' designator specifically indicates axillary and upper extremity lymph nodes
Clinical Significance
Mycosis fungoides with involvement of axillary and upper limb lymph nodes indicates disease progression beyond the skin. Axillary lymphadenopathy in mycosis fungoides patients may be reactive (dermatopathic) or represent true lymphomatous involvement, and pathologic distinction is important for accurate staging. True lymph node involvement indicates Stage III-IV disease requiring systemic treatment.
Documentation Requirements
- ✓Skin biopsy confirming mycosis fungoides
- ✓Axillary lymph node biopsy or imaging confirming involvement
- ✓Distinction between dermatopathic lymphadenopathy and lymphomatous involvement
- ✓TNMB staging
- ✓Treatment plan reflecting nodal disease
Commonly Confused Codes
C84.00 — Mycosis fungoides, unspecified site: Use C84.04 when axillary/upper limb lymph node involvement is confirmedC84.14 — Sezary disease, axilla/upper limb: Distinct disease entity requiring circulating malignant T-cellsC77.3 — Secondary malignant neoplasm, axillary lymph nodes: Do not use for primary lymphoma
Code Hierarchy
└C84Mature T/NK-cell lymphomas└C84.0Mycosis fungoides└C84.04Mycosis fungoides, lymph nodes of axilla and upper limb
└C84.04Mycosis fungoides, lymph nodes of axilla and upper limb