2019 ICD-10-CM Diagnosis Code C96.6

Unifocal Langerhans-cell histiocytosis

    2016 2017 2018 2019 Billable/Specific Code
  • C96.6 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2019 edition of ICD-10-CM C96.6 became effective on October 1, 2018.
  • This is the American ICD-10-CM version of C96.6 - other international versions of ICD-10 C96.6 may differ.
Applicable To
  • Eosinophilic granuloma
  • Histiocytosis X, unifocal
  • Histiocytosis X NOS
  • Langerhans-cell histiocytosis NOS
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as C96.6. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • multifocal and multisysemic (disseminated) Langerhans-cell histiocytosis (
    ICD-10-CM Diagnosis Code C96.0

    Multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Histiocytosis X, multisystemic
    • Letterer-Siwe disease
    Type 1 Excludes
    • adult pulmonary Langerhans cell histiocytosis (J84.82)
    • multifocal and unisystemic Langerhans-cell histiocytosis (C96.5)
    • unifocal Langerhans-cell histiocytosis (C96.6)
    C96.0
    )
  • multifocal and unisystemic Langerhans-cell histiocytosis (
    ICD-10-CM Diagnosis Code C96.5

    Multifocal and unisystemic Langerhans-cell histiocytosis

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Hand-Schüller-Christian disease
    • Histiocytosis X, multifocal
    Type 1 Excludes
    • multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis (C96.0)
    • unifocal Langerhans-cell histiocytosis (C96.6)
    C96.5
    )
The following code(s) above C96.6 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to C96.6:
  • C00-D49
    2019 ICD-10-CM Range C00-D49

    Neoplasms

    Note
    • Functional activity
    • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
    • Morphology [Histology]
    • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
    • Primary malignant neoplasms overlapping site boundaries
    • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
    • Malignant neoplasm of ectopic tissue
    • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
    Neoplasms
  • C81-C96
    2019 ICD-10-CM Range C81-C96

    Malignant neoplasms of lymphoid, hematopoietic and related tissue

    Type 2 Excludes
    • 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)
    Malignant neoplasms of lymphoid, hematopoietic and related tissue
  • C96
    ICD-10-CM Diagnosis Code C96

    Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • personal history of other malignant neoplasms of lymphoid, hematopoietic and related tissues (Z85.79)
    Other and unspecified malignant neoplasms of lymphoid, hematopoietic and related tissue
Approximate Synonyms
  • Histiocytosis x
  • Histiocytosis, langerhans cell, unifocal
  • Histiocytosis, unifocal langerhans-cell
  • Langerhans cell histiocytosis
  • Langerhans cell histiocytosis, unifocal (clinical)
Clinical Information
  • A clinical variant of langerhans cell histiocytosis characterised by unifocal involvement of a bone (most often), skin, or lung. Patients are usually older children or adults usually presenting with a lytic bone lesion. The etiology is unknown. Morphologically, eosinophilic granuloma is characterised by the presence of langerhans cells in a characteristic milieu which includes histiocytes, eosinophiles neutrophiles, and small, mature lymphocytes.
  • A group of disorders resulting from the abnormal proliferation of and tissue infiltration by langerhans cells which can be detected by their characteristic birbeck granules (x bodies), or by monoclonal antibody staining for their surface cd1 antigens. Langerhans-cell granulomatosis can involve a single organ, or can be a systemic disorder.
  • A group of rare disorders in which too many langerhans cells (a type of white blood cell) grow in certain tissues and organs including the bones, skin, and lungs, and damage them. Langerhans cell histiocytosis may also affect the pituitary gland (which makes hormones that control other glands and many body functions, especially growth). Langerhans cell histiocytosis is most common in children and young adults.
  • A multifocal, multisystem form of langerhans-cell histiocytosis. There is involvement of multiple organ systems including the bones, skin, liver, spleen, and lymph nodes. Patients are usually infants presenting with fever, hepatosplenomegaly, lymphadenopathy, bone and skin lesions, and pancytopenia.
  • A multifocal, unisystem form of langerhans-cell histiocytosis. There is involvement of multiple sites in one organ system, most frequently the bone. Patients are usually young children presenting with multiple destructive bone lesions.
  • A neoplastic proliferation of langerhans cells which contain birbeck granules by ultrastructural examination. Three major overlapping syndromes are recognized: eosinophilic granuloma, letterer-siwe disease, and hand-schuller-christian disease. The clinical course is generally related to the number of organs affected at presentation. (who, 2001)
  • Group of disorders of histiocyte proliferation which includes letterer-siwe disease; hand-schueller-christian syndrome; and eosinophilic granuloma; langerhans cells are components of the lesions.
  • Most benign clinical form of langerhans-cell histiocytosis, which involves localized nodular lesions of the gastric mucosa, small intestine, bones, lungs, or skin, with infiltration by eosinophils; the proliferating cell that appears to be responsible for the clinical manifestations is the langerhans cell.
  • The most benign and common form of langerhans-cell histiocytosis which involves localized nodular lesions predominantly of the bones but also of the gastric mucosa, small intestine, lungs, or skin, with infiltration by eosinophils.
ICD-10-CM C96.6 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):
  • 642 Inborn and other disorders of metabolism

Convert C96.6 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
Code annotations containing back-references to C96.6:
  • Type 1 Excludes: C96.0
    , C96.5
    , D76
    , D76
    , D76
    , D76
    , E88
    ICD-10-CM Diagnosis Code C96.0

    Multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Histiocytosis X, multisystemic
    • Letterer-Siwe disease
    Type 1 Excludes
    • adult pulmonary Langerhans cell histiocytosis (J84.82)
    • multifocal and unisystemic Langerhans-cell histiocytosis (C96.5)
    • unifocal Langerhans-cell histiocytosis (C96.6)
    ICD-10-CM Diagnosis Code C96.5

    Multifocal and unisystemic Langerhans-cell histiocytosis

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Hand-Schüller-Christian disease
    • Histiocytosis X, multifocal
    Type 1 Excludes
    • multifocal and multisystemic (disseminated) Langerhans-cell histiocytosis (C96.0)
    • unifocal Langerhans-cell histiocytosis (C96.6)
    ICD-10-CM Diagnosis Code D76

    Other specified diseases with participation of lymphoreticular and reticulohistiocytic tissue

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • (Abt-) Letterer-Siwe disease (C96.0)
    • eosinophilic granuloma (C96.6)
    • Hand-Schüller-Christian disease (C96.5)
    • histiocytic medullary reticulosis (C96.9)
    • histiocytic sarcoma (C96.A)
    • histiocytosis X, multifocal (C96.5)
    • histiocytosis X, unifocal (C96.6)
    • Langerhans-cell histiocytosis, multifocal (C96.5)
    • Langerhans-cell histiocytosis NOS (C96.6)
    • Langerhans-cell histiocytosis, unifocal (C96.6)
    • leukemic reticuloendotheliosis (C91.4-)
    • lipomelanotic reticulosis (I89.8)
    • malignant histiocytosis (C96.A)
    • malignant reticulosis (C86.0)
    • nonlipid reticuloendotheliosis (C96.0)
    ICD-10-CM Diagnosis Code D76

    Other specified diseases with participation of lymphoreticular and reticulohistiocytic tissue

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • (Abt-) Letterer-Siwe disease (C96.0)
    • eosinophilic granuloma (C96.6)
    • Hand-Schüller-Christian disease (C96.5)
    • histiocytic medullary reticulosis (C96.9)
    • histiocytic sarcoma (C96.A)
    • histiocytosis X, multifocal (C96.5)
    • histiocytosis X, unifocal (C96.6)
    • Langerhans-cell histiocytosis, multifocal (C96.5)
    • Langerhans-cell histiocytosis NOS (C96.6)
    • Langerhans-cell histiocytosis, unifocal (C96.6)
    • leukemic reticuloendotheliosis (C91.4-)
    • lipomelanotic reticulosis (I89.8)
    • malignant histiocytosis (C96.A)
    • malignant reticulosis (C86.0)
    • nonlipid reticuloendotheliosis (C96.0)
    ICD-10-CM Diagnosis Code D76

    Other specified diseases with participation of lymphoreticular and reticulohistiocytic tissue

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • (Abt-) Letterer-Siwe disease (C96.0)
    • eosinophilic granuloma (C96.6)
    • Hand-Schüller-Christian disease (C96.5)
    • histiocytic medullary reticulosis (C96.9)
    • histiocytic sarcoma (C96.A)
    • histiocytosis X, multifocal (C96.5)
    • histiocytosis X, unifocal (C96.6)
    • Langerhans-cell histiocytosis, multifocal (C96.5)
    • Langerhans-cell histiocytosis NOS (C96.6)
    • Langerhans-cell histiocytosis, unifocal (C96.6)
    • leukemic reticuloendotheliosis (C91.4-)
    • lipomelanotic reticulosis (I89.8)
    • malignant histiocytosis (C96.A)
    • malignant reticulosis (C86.0)
    • nonlipid reticuloendotheliosis (C96.0)
    ICD-10-CM Diagnosis Code D76

    Other specified diseases with participation of lymphoreticular and reticulohistiocytic tissue

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • (Abt-) Letterer-Siwe disease (C96.0)
    • eosinophilic granuloma (C96.6)
    • Hand-Schüller-Christian disease (C96.5)
    • histiocytic medullary reticulosis (C96.9)
    • histiocytic sarcoma (C96.A)
    • histiocytosis X, multifocal (C96.5)
    • histiocytosis X, unifocal (C96.6)
    • Langerhans-cell histiocytosis, multifocal (C96.5)
    • Langerhans-cell histiocytosis NOS (C96.6)
    • Langerhans-cell histiocytosis, unifocal (C96.6)
    • leukemic reticuloendotheliosis (C91.4-)
    • lipomelanotic reticulosis (I89.8)
    • malignant histiocytosis (C96.A)
    • malignant reticulosis (C86.0)
    • nonlipid reticuloendotheliosis (C96.0)
    ICD-10-CM Diagnosis Code E88

    Other and unspecified metabolic disorders

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • histiocytosis X (chronic) (C96.6)
    Use Additional
    • codes for associated conditions

Diagnosis Index entries containing back-references to C96.6:
  • Granuloma L92.9
    ICD-10-CM Diagnosis Code L92.9

    Granulomatous disorder of the skin and subcutaneous tissue, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Type 2 Excludes
    • bone
      • eosinophilic C96.6
      • lung C96.6
    • eosinophilic C96.6
      • bone C96.6
      • lung C96.6
    • lung (infectious) - see also Fibrosis, lung
      • eosinophilic C96.6
  • Histiocytosis D76.3
    ICD-10-CM Diagnosis Code D76.3

    Other histiocytosis syndromes

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Reticulohistiocytoma (giant-cell)
    • Sinus histiocytosis with massive lymphadenopathy
    • Xanthogranuloma
    • Langerhans' cell NEC C96.6
      • unifocal C96.6 (X)
    • mononuclear phagocytes NEC D76.1
      ICD-10-CM Diagnosis Code D76.1

      Hemophagocytic lymphohistiocytosis

        2016 2017 2018 2019 Billable/Specific Code
      Applicable To
      • Familial hemophagocytic reticulosis
      • Histiocytoses of mononuclear phagocytes
      • Langerhans' cells C96.6
    • X NEC C96.6
      • chronic C96.6
      • unifocal C96.6

ICD-10-CM Codes Adjacent To C96.6
C95.92 …… in relapse
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
C96.20 …… unspecified
C96.21 Aggressive systemic mastocytosis
C96.22 Mast cell sarcoma
C96.29 Other malignant mast cell neoplasm
C96.4 Sarcoma of dendritic cells (accessory cells)
C96.5 Multifocal and unisystemic Langerhans-cell histiocytosis
C96.6 Unifocal Langerhans-cell histiocytosis
C96.A Histiocytic sarcoma
C96.Z Other specified malignant neoplasms of lymphoid, hematopoietic and related tissue
C96.9 Malignant neoplasm of lymphoid, hematopoietic and related tissue, unspecified
D00 Carcinoma in situ of oral cavity, esophagus and stomach
D00.0 Carcinoma in situ of lip, oral cavity and pharynx
D00.00 Carcinoma in situ of oral cavity, unspecified site
D00.01 Carcinoma in situ of labial mucosa and vermilion border
D00.02 Carcinoma in situ of buccal mucosa
D00.03 Carcinoma in situ of gingiva and edentulous alveolar ridge
D00.04 Carcinoma in situ of soft palate

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.