Related Experiment Video
Updated: Jun 13, 2026
Patient-derived Orthotopic Xenograft Models for Human Urothelial Cell Carcinoma and Colorectal Cancer Tumor Growth and Spontaneous Metastasis
Published on: May 12, 2019
FGFR3-Altered Urothelial Carcinoma: Clinicopathologic Observations With Emphasis on Variant Histology
Katrina Collins1, Liang Cheng2
1Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
Purpose:
The purpose of this study was to determine the frequency and spectrum of FGFR3 alterations in urothelial carcinoma and to evaluate their association with histologic variants.
Materials And Methods:
A total of 190 cases of urothelial carcinoma were analyzed for alterations in FGFR3.
Results:
After consolidation at the patient level, 33 (17%) patients harbored FGFR3 alterations. S249C (n = 17; 52%) and Y373C (n = 8; 24%) were the predominant mutations, whereas FGFR3::TACC fusion events accounted for 4 (12%) cases. R248C (n = 3; 9%) and G370C (n = 1; 3%) were less frequent. Variant histology was identified in 25 of 33 (76%) tumors, with micropapillary differentiation being the most common pattern (n = 13; 39%), followed by squamous differentiation (n = 7; 21%). Both micropapillary tumors and tumors with squamous differentiation exclusively harbored S249C or Y373C mutations.
Conclusions:
The consistent association of these variant patterns with S249C or Y373C mutations suggests that hotspot FGFR3 alterations can persist across morphologic contexts in noninvasive and invasive disease. Recognition of these variant histologies may therefore support consideration of targeted FGFR testing.
