1
Return

PATZ1 Immunohistochemistry Aids in the Diagnosis of PATZ1-Rearranged Sarcomas

delete2026-06-10
delete0
PRE
AI
M
Melissa S. Gildenberg
A
Andrew L. Folpe
G
Gregory W. Charville
Y
Yin P. Hung
J
Jason L. Hornick
W
William J. Anderson *
DOI:10.1016/j.modpat.2026.101021delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
PATZ1-rearranged sarcomas are diagnostically challenging due to their rather non-specific morphology and immunophenotype. These tumors are characterized by bland, round-to-spindled cells within a fibromyxoid matrix with variable microcysts, fibrous septa, hyalinized vessels, and cellular whorls. PATZ1-rearranged sarcomas are often positive for neural, skeletal muscle, and epithelial markers. Identification of these tumors is further complicated by the cryptic nature of the characteristic EWSR1::PATZ1 fusion, which generally makes fluorescence in situ hybridization analysis unreliable if rearrangement is not detected. As a result, costly and time-intensive molecular assays are often currently necessary for definitive diagnosis. The purpose of this study was to assess immunohistochemistry (IHC) for PATZ1 as a surrogate for detecting the gene fusion. In total, 533 tumors from whole-tissue sections and tissue microarrays were evaluated, including 14 PATZ1-rearranged sarcomas as well as other benign and malignant mesenchymal neoplasms. IHC for PATZ1 was positive in 12/14 (86%) PATZ1-rearranged sarcomas. Of the remaining tumor types, 495 (95%) were negative for PATZ1. Notably, PATZ1 expression was observed in a subset of other tumor types, including myoepithelial carcinoma (2/4; 50%), myoepithelioma (2/15; 13%), rhabdomyosarcoma (13/99; 13%), desmoplastic small round cell tumor (1/10; 10%), dermatofibrosarcoma protuberans (1/10; 10%), myxoid liposarcoma (1/16; 6%), schwannoma (1/22; 5%), and malignant peripheral nerve sheath tumor (3/70; 4%). The 13 RMS cases that were positive were classified as embryonal (n=7), alveolar (n=5), and RMS, NOS (n=1). In conclusion, PATZ1 IHC is moderately sensitive and specific for PATZ1-rearranged sarcomas, and it may be a helpful diagnostic marker for this challenging tumor. While most tumors with morphologic overlap with PATZ1-rearranged sarcomas are negative for PATZ1 by IHC, expression in a subset of myoepithelial tumors and rhabdomyosarcomas represents a potential diagnostic pitfall.

Journal

Modern Pathology cover
Modern Pathology
IF:
5.5
Papers:
5.2K
Citations:
1.8W

Organization

M
mayo clinic
Scholars:
8.0W
Papers: 6.5W
Citations: 84
S
stanford university
Scholars:
9.2K
Papers: 3.6K
Citations: 0
Cited Papers

Cited Papers

Citing Papers

Citing Papers