ICD-O-3 Morphology

Effective 2010 and later


for cases diagnosed 2010 and later

Primary Site(s)

See Module 7
Most common sites of involvement: lymph nodes, spleen, soft tissue


Not Applicable

Module Rule


Alternate Names

Cytokeratin-positive interstitial reticulum cell tumor


Fibroblastic reticular cell tumor is very rare. Tumors diagnosed as cytokeratin-positive interstitial reticulum cell tumors, probably constitute the same entity.

Abstractor Notes

(This code is effective for cases diagnosed 2010 and later.) Fibroblastic reticular cell tumor is extremely rare.

Clinical outcome is variable with some patients dying of the disease. The tumor is similar to follicular dendritic cell sarcoma (9758/3) and Interdigitating dendritic cell sarcoma (9757/3) but lacks the immunophenotypic profile of these tumor types.

Definitive Diagnostic Methods

Histologic confirmation

Genetics Data



CD68 variably immunoreactive
Cytokeratin (in dendritic pattern) variably immunoreactive
Desmin variably immunoreactive
SMA variably immunoreactive


Radiation therapy

Transformations to

There are no known transformations

Transformations from

There are no known transformations

Corresponding ICD-9 Codes

202.9 Other and unspecified malignant neoplasms

Corresponding ICD-10 Codes

C96.7 Other specified malignant neoplasms of lymphoid, hematopoietic

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

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

Signs and Symptoms

Easy bruising or bleeding
Generalized papules (single or multiple)
Painful bone lesion
Skin rash
Weight loss

Diagnostic Exams

Progression and Transformation


Epidemiology and Mortality

Incidence: very rare
Survival: limited data, spontaneous regression to rapid progression has been seen


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: 479-480

International Classification of Diseases for Oncology, Third Edition, First Revision. Geneva: World Health Organization, 2013.
Section: ICD-O-3.1 (2011) Morphological Codes
Pages: http://codes.iarc.fr/codegroup/2

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