LCH, NOS

Per the IARC/WHO Committee for ICD-O and included in the WHO Tumors of Hematopoietic and Lymphoid Tissues, Revised 4th Ed, Volume 2, only LCH disseminated/multisystem is now assigned /3 behavior (malignant). All other forms of LCH are no longer malignant (/3 behavior) and are not reportable except for benign Brain and CNS tumors (9751/1).

Langerhans cell histiocytosis presents in several different forms

1. SOLITARY/UNIFOCAL form: Usually occurs in older children or adults who most commonly present with a lytic bone lesion eroding the cortex. Solitary lesions may occur at other sites as mass lesions or enlarged lymph nodes. Other sites include adjacent soft tissue (skull, femur, vertebra, pelvic bones, and ribs) and less commonly lymph nodes, skin and lung. (Only reportable if benign Brain and CNS)

2. MULTIFOCAL/UNISYSTEM multifocal disease-Usually occurs in young children who present with multiple or sequential destructive bone lesions often associated with adjacent soft tissue masses. Skull and mandibular involvement is common. Diabetes insipidus follows cranial involvement. (Only reportable if benign Brain and CNS

3. DISSEMINATED/MULTISYSTEM: Occurs in infants who present with fever, cytopenia, skin and bone lesions, and hepatosplenomegaly. Pulmonary disease in childhood is clinically variable. The skin, bone, and marrow are preferential sites of involvement. The liver and spleen are also common sites; however, they are typically metastatic and not the primary site. Involvement of bone marrow, liver, and lung are regarded as high-risk factors. (See 9751/3)

Self-healing Langerhans cell histiocytosis (LCH) of the skin means that the disease regressed without treatment. This is a known phenomenon and is non reportable.

NOTE: Langerhans histiocytosis, unifocal (9752/1 in ICD-O-3 for 2001-2009) and Langerhans cell histiocytosis, multifocal (9753/1), and are now grouped with Langerhans cell histiocytosis, 9751/1.

Acute progressive histiocytosis X

Eosinophilic granuloma

Hand-Schuller-Christian disease

Histiocytic medullary reticulosis [OBS]

Histocytosis X [OBS]

Langerhans cell granulomatosis

Langerhans cell granulomatosis, unifocal

Langerhans cell histiocytosis, generalized

Langerhans cell histiocytosis, mono-ostotic

Langerhans cell histiocytosis, multifocal

Langerhans cell histiocytosis, poly-ostotic

Langerhans cell histiocytosis, unifocal

Langerhans cell histocytosis, NOS

Letterer-Siwe disease

Nonlipid reticuloendotheliosis [OBS]

Self-healing Langerhans cell histiocytosis (LCH) of the skin

Langerhans cell histiocytosis (LCH) is a clonal neoplastic proliferation of Langerhans-type cells that express CD1a, langerin and S100 protein and show Birbeck granules by ultrastructural examination.

202.5 Letterer-Siwe Disease

277.89 Other specified disorders of metabolism

D76.0 Langerhans' cell histiocytosis, not elsewhere classified

Swerdlow SH, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds):
WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition)
IARC: Lyon 2017
Section: Histiocytic and dendritic cell neoplasms
Pages: Pages: 470-472

National Cancer Institute
Section: General Information About Langerhans Cell Histiocytosis (LCH)
Pages: https://www.cancer.gov/types/langerhans/hp/langerhans-treatment-

International Classification of Diseases for Oncology, Third Edition, Second Revision. Geneva: World Health Organization, 2020
Section: ICD-O-3.2 (2020) Morphological Codes
Pages: http://www.iacr.com.fr/index.php?option=com_content&view=category&layout=blog&id=100&Itemid=577