Name

Indeterminate dendritic cell tumor

ICD-O-3 Morphology

9757/3: Interdigitating dendritic cell sarcoma
Effective 2001 and later

Reportable

for cases diagnosed 2001 and later

Primary Site(s)

See Module 7
Most common sites of involvement: lymph nodes, skin, soft tissue, other extranodal presentations

Abstractor Notes

Visceral organs commonly affected include the liver, spleen, kidney and lung. Stage may be an important prognostic factor; however, histological features have not been correlated with clinical outcome. The clinical course has been highly variable, ranging from spontaneous regression to rapid progression.

Diagnostic Confirmation

This histology can be determined by positive histology (including peripheral blood) with or without genetics and/or immunophenotyping. Review the Definitive Diagnostic Methods, Immunophenotyping and Genetics Data sections below, and the instructions in the Hematopoietic Manual for further guidance on assigning Diagnostic confirmation.

Grade

Not Applicable

Module Rule

None

Alternate Names

Dendritic cell sarcoma, NOS
Dendritic cell tumor, NOS
IDCS
Indeterminate cell histiocytosis
Interdigitating dendritic cell sarcoma
Interdigitating cell sarcoma

Definition

IDC sarcoma is a neoplastic proliferation of spindle to ovoid cells with phenotypic features similar to those of interdigitating dendritic cells. Very rare neoplasm with most studies representing single case reports or very small series.

Rare sarcoma arising from the interdigitating reticulum cells in the T-cell area of the lymph node and forming a node-based tumor.

Indeterminate cells are the proposed precursor of Langerhans cells, so this malignancy is in myeloid-derived dendritic cells in contrast to fibroblastic reticular cell tumor (9759/3). These lesions are usually based in the dermis but may extend into the subcutaneous fat. The infiltrate is diffuse, comprising cells resembling Langerhans cells.

Definitive Diagnostic Methods

Genetic testing
Histologic confirmation
Immunophenotyping

Genetics Data

Immunoglobulin heavy chain gene and T-cell receptor beta, delta and gamma chain genes are in germline configuration

Immunophenotyping

CD1a expression
CD4 positive
CD21 negative
CD23 negative
CD30 negative
CD35 negative
CD45 positive
CD68 positive
CD163 negative
Ki-67 proliferation index highly variable
Langerin negative
Lysozyme positive
S100 protein expression

Treatments

Chemotherapy
Radiation therapy
Surgery

Transformations to

There are no known transformations

Transformations from

There are no known transformations

Corresponding ICD-9 Codes

202.9 Other and unspecified malignant neoplasm of lymphoid and histiocytic tissue

Corresponding ICD-10 Codes

C96.7 Other specified malignant neoplasms of lymphoid, hematopoietic, and related tissue
C96.9 Malignant neoplasms of lymphoid, hematopoietic, and related tissue, unspecified

Corresponding ICD-10-CM Codes (U.S. only)

C96.4 Sarcoma of dendritic cells (accessory cells) (effective October 01, 2015)

Signs and Symptoms

Asymptomatic mass
Drenching night sweats
Fatigue
Fever
Generalized lymphadenopathy (rare)

Diagnostic Exams

Biopsy
Blood chemistry studies
Bone marrow aspiration and biopsy
Bone scan
BRAF testing
CT (CAT) scan
Endoscopy
Flow cytometry
Immunophenotyping
Liver function test
Neurological exam
PET (positron emission tomography) scan
Ultrasound exam
Urinalysis
Water deprivation test

Progression and Transformation

None

Epidemiology and Mortality

Age: predominantly adults
Incidence: very rare disease
Sex: slight male predominance
Survival: aggressive lymphoma, poor survival, ~1/2 of patients die of disease

Sources

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: 475-476

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

National Cancer Institute
Section: General Information About Langerhans Cell Histiocytosis (LCH)
Pages: https://www.cancer.gov/types/langerhans/hp/langerhans-treatment-pdq#section/_178%20or%20http://www.cancer.gov/types/langerhans/patient/langerhans-treatment-pdq
Glossary