Stains & CD markers
IFITM1
Copyright: 2022, PathologyOutlines.com, Inc.
PubMed Search: IFITM1 [TI]
IFITM1
Author: Aurelia Busca, M.D., Ph.D.
Editorial Board Member: Christian M. Schürch, M.D., Ph.D.
Deputy Editor-in-Chief: Jennifer A. Bennett, M.D.
Last author update: 10 March 2022
Last staff update: 10 March 2022
Copyright: 2022, PathologyOutlines.com, Inc.
PubMed Search: IFITM1 [TI]
Table of Contents
Definition / general | Essential features | Terminology | Pathophysiology | Interpretation | Uses by pathologists | Prognostic factors | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative staining | Sample pathology report | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Busca A. IFITM1. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsIFITM1.html. Accessed December 25th, 2024.
Definition / general
- Part of the IFITM family (interferon induced transmembrane protein); involved in interferon mediated, antiviral immune response and tumor growth and proliferation
- Useful as a marker of endometrial stromal differentiation
Essential features
- Part of the IFITM family (interferon induced transmembrane protein, IFITM1, IFITM2, IFITM3)
- Downstream molecule of the Wnt / beta catenin signaling pathway in pregnancy related uterine growth and uterine development
- Marker of endometrial stroma and endometrial stromal differentiation in spindle cell lesions
- Increased IFITM1 expression correlates with increased TNM stage and poor prognosis in gallbladder, colorectal and breast carcinomas
Terminology
- CD225
Pathophysiology
- Downstream molecule of the Wnt / beta catenin signaling pathway in pregnancy related uterine growth in mouse models (Reprod Fertil Dev 2011;23:798)
- Mediates gonadal development in mouse models (Dev Cell 2005;9:745)
- IFITM1 overexpression promotes breast cancer growth via JAK / STAT activation in mouse models and cell lines (Cancer Lett 2017;399:29)
Interpretation
- Cytoplasmic staining
Uses by pathologists
- Support endometrial stromal differentiation versus smooth muscle differentiation in spindle cell lesions; often used as part of a panel with CD10 and caldesmon (BMC Cancer 2021;21:1047, Int J Gynecol Pathol 2018;37:372, Mod Pathol 2014;27:569)
- Differentiate myometrial invasion in endometrial adenocarcinoma (no endometrial stroma present around tumor foci, IFITM1 negative) from tumor involvement of foci of adenomyosis (presence of residual endometrial type stroma, IFITM1 positive) (Am J Clin Pathol 2016;145:486)
- Highlight endometrial type stroma in endometriosis (Reprod Sci 2020;27:1595)
Prognostic factors
- Increased IFITM1 expression correlates with increased TNM stage and poor prognosis in gallbladder, colorectal and breast carcinomas (Pathol Oncol Res 2019;25:157, Oncotarget 2016;7:86039, Cancer Res 2006;66:1949, Cancer Lett 2017;399:29)
- IFITM1 promotes distant metastasis in xenograft models of human small cell lung cancer (Int J Mol Sci 2020;21:4934)
Microscopic (histologic) images
Contributed by Aurelia Busca, M.D., Ph.D.
Myometrial invasion
Myometrial invasion, IFITM1
Adenomyosis
Adenomyosis, IFITM1
Positive staining - normal
- Endometrial stroma within the endometrium and within areas of adenomyosis, irrespective of menstrual phase (Mod Pathol 2014;27:569)
- Lymph nodes, endothelial cells, colon, epididymis, ovarian stroma (The Human Protein Atlas: IFITM1 [Accessed 20 February 2022])
Positive staining - disease
- Endometrial stromal tumors (86.7%) (BMC Cancer 2021;21:1047)
- Endometrial stromal sarcoma, low grade (13/16) (Mod Pathol 2014;27:569)
- Endometriosis, stromal tissue (100%) (Reprod Sci 2020;27:1595)
Negative staining
- Leiomyomas are mostly negative (4/30 of leiomyoma cases are positive) (Mod Pathol 2014;27:569)
- Cellular leiomyomas are mostly negative (18.2% positive) (BMC Cancer 2021;21:1047)
- High grade endometrial stromal sarcoma, limited experience (2 of 2 cases tested) (Int J Gynecol Pathol 2018;37:372, Mod Pathol 2014;27:569)
Sample pathology report
- Endometrium, curettings:
- Spindle cell lesion, most consistent with endometrial stromal neoplasm (see comment)
- Comment: Sections show a spindle cell lesion with bland nuclear features, resembling endometrial stroma and presence of small arterioles. By immunohistochemistry, the lesional cells are positive for CD10 and IFITM1 (endometrial stromal markers) and negative for desmin and caldesmon (smooth muscle markers). The findings are most consistent with a low grade endometrial stromal neoplasm. Definite classification (endometrial stromal nodule versus low grade endometrial stromal sarcoma) requires a resection specimen.
Board review style question #1
Which of the following statements is true about the endometrial carcinoma and IFITM1 immunostain illustrated in the photos shown above?
- IFITM1 highlights the endometrial stroma
- IFITM1 highlights the myometrium
- Pattern of staining supports the fact that the tumor is not invasive into myometrium
- Tumor is IFITM1 positive
Board review style answer #1
Board review style question #2
Which of these lesions is typically IFITM1 positive?
- Cellular leiomyoma
- Conventional leiomyoma
- High grade endometrial stromal sarcoma
- Low grade endometrial stromal sarcoma
Board review style answer #2
