PATZ1 Immunohistochemistry Aids in the Diagnosis of PATZ1-Rearranged Sarcomas.

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.

Of the remaining tumor types, 495 (95%) were negative for PATZ1.

In conclusion, PATZ1 immunohistochemistry is moderately sensitive and specific for PATZ1-rearranged sarcomas, and it may be a helpful diagnostic marker for this challenging tumor.