An official website of the United States government
Home
This neoplasm is not reportable.
Name
In situ follicular B-cell neoplasm (ISFN)
Reportability
This neoplasm is not reportable
Primary Site(s)
See Module 7
This hematopoietic disease is not reportable for the U.S. except for primary sites C700-C729, C751-C753.
Canada, refer to your specific province for reportability requirements.
Most common primary sites: lymph nodes, intestine, spleen, tonsils, thyroid, and salivary glands
Canada, refer to your specific province for reportability requirements.
Most common primary sites: lymph nodes, intestine, spleen, tonsils, thyroid, and salivary glands
Abstractor Notes
Alternate Names
In situ follicular lymphoma
In situ follicular neoplasia
Definition
In situ follicular neoplasia (ISFN), formerly referred to In situ follicular B-cell neoplasm (ISFN) is defined as partial or complete colonization of some reactive germinal centers by follicular B cells with IGH::BCL2 fusion and strong BCL2 expression in otherwise normal reactive lymph nodes or lymphoid tissues at extranodal sites. (WHO 5th edition)
Corresponding ICD-10 Codes (Cause of Death codes only)
D47.7 Other specified neoplasms of uncertain or unknown behavior of lymphoid, hematopoietic, and related tissue
Corresponding ICD-10-CM Codes (U.S. only)
D47.Z9 Other specified neoplasms of uncertain behavior of lymphoid, hematopoietic and related tissue (effective October 01, 2015)
Sources
WHO Classification of Tumours Editorial Board. Haematolymphoid tumours. Lyon (France): International Agency for Research on Cancer; 2024. (WHO classification of tumours series, 5th ed.; vol. 11). https://publications.iarc.who.int/637.
Section: Follicular lymphoma
Pages: Part B: 421-422
Section: Follicular lymphoma
Pages: Part B: 421-422
International Classification of Diseases for Oncology, 3rd edition (including revisions). Geneva: World Health Organization, 2001, 2011, 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
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
PDQ® Adult Treatment Editorial Board. PDQ Indolent B-Cell Non-Hodgkin Lymphoma Treatment. Bethesda, MD: National Cancer Institute. Updated <02/18/2025>. Available at: https://www.cancer.gov/types/lymphoma/hp/indolent-b-cell-lymphoma-treatment-pdq. Accessed <03/04/2025>. [PMID: 37437080]
Section: Indolent B-Cell Non-Hodgkin Lymphoma Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/lymphoma/hp/adult-nhl-treatment-pdq
Section: Indolent B-Cell Non-Hodgkin Lymphoma Treatment (PDQ®)–Health Professional Version
Pages: https://www.cancer.gov/types/lymphoma/hp/adult-nhl-treatment-pdq
