C96.6 is the authoritative medical code for Unifocal Langerhans-cell histiocytosis. This classification is used in medical billing and clinical recording to specify the clinical criteria for unifocal langerhans-cell histiocytosis (ICD-10-CM C96.6), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Official Registry Overview & Definition
Unifocal Langerhans-cell histiocytosis is a billable ICD-10-CM diagnosis code C96.6. Inclusion terms: Eosinophilic granuloma; Histiocytosis X, unifocal; Histiocytosis X NOS; Langerhans-cell histiocytosis NOS. Excludes1 (not coded here): multifocal and multisysemic disseminated Langerhans-cell histiocytosis C96.0; multifocal and unisystemic Langerhans-cell histiocytosis C96.5; personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues Z85.79. Excludes2 (not included here): Kaposi's sarcoma of lymph nodes C46.3; secondary and unspecified neoplasm of lymph nodes C77.-; secondary neoplasm of bone marrow C79.52; secondary neoplasm of spleen C78.89.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for C96.6 in the official ICD-10-CM tabular list.
Inclusion Terms
Alternative terms the tabular list files under this code.
- Eosinophilic granuloma
- Histiocytosis X, unifocal
- Histiocytosis X NOS
- Langerhans-cell histiocytosis NOS
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- multifocal and multisysemic disseminated Langerhans-cell histiocytosis C96.0
- multifocal and unisystemic Langerhans-cell histiocytosis C96.5
- personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues Z85.79
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- Kaposi's sarcoma of lymph nodes C46.3
- secondary and unspecified neoplasm of lymph nodes C77.-
- secondary neoplasm of bone marrow C79.52
- secondary neoplasm of spleen C78.89
Frequently Asked Questions (FAQ) & Clinical Guidance
What can't be coded together with C96.6?
Per Excludes1 instructions, C96.6 must not be reported with: multifocal and multisysemic (disseminated) Langerhans-cell histiocytosis (C96.0); multifocal and unisystemic Langerhans-cell histiocytosis (C96.5); personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues (Z85.79).
Can C96.6 be reported alongside related conditions?
Per Excludes2 instructions, C96.6 and the following may both be reported when both are present: Kaposi's sarcoma of lymph nodes (C46.3); secondary and unspecified neoplasm of lymph nodes (C77.-); secondary neoplasm of bone marrow (C79.52); secondary neoplasm of spleen (C78.89).
What conditions are included under C96.6?
Unifocal Langerhans-cell histiocytosis includes: Eosinophilic granuloma; Histiocytosis X, unifocal; Histiocytosis X NOS; Langerhans-cell histiocytosis NOS.
Codes in This Family (8)
Official ICD-10-CM classifications in the same code family as C96.6, with their registry titles.
- C96 — Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue
- C96.0 — Multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis
- C96.2 — Malignant mast cell neoplasm
- C96.4 — Sarcoma of dendritic cells (accessory cells)
- C96.5 — Multifocal and unisystemic Langerhans-cell histiocytosis
- C96.9 — Malignant neoplasm of lymphoid, hematopoietic and related tissue, unspecified
- C96.A — Histiocytic sarcoma
- C96.Z — Other specified malignant neoplasms of lymphoid, hematopoietic and related tissue
Indexed Clinical Terms (12)
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.
- Granuloma, bone, eosinophilic
- Granuloma, bone, lung
- Granuloma, eosinophilic
- Granuloma, eosinophilic, bone
- Granuloma, eosinophilic, lung
- Granuloma, lung (infectious), eosinophilic
- Histiocytosis, Langerhans' cell NEC
- Histiocytosis, Langerhans' cell NEC, unifocal (X)
- Histiocytosis, mononuclear phagocytes NEC, Langerhans' cells
- Histiocytosis, X NEC
- Histiocytosis, X NEC, chronic
- Histiocytosis, X NEC, unifocal
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures: