Immunohistochemical detection of the Wilms' tumour gene WT1 in desmoplastic small round cell tumour

The desmoplastic small round cell tumour (DSRCT) is a rare, highly malignant neoplasm usually presenting in the abdomen of adolescent males. A characteristic translocation between the Ewing's sarcoma gene on chromosome 22 and the Wilms' tumour gene WT1 on chromosome 11 has been described, producing a fusion gene with expression of the DNA binding area of WT1. Some Wilms' tumour antibodies recognize epitopes of this part of the WT1 protein. All four cases of DSRCT examined showed strong staining of the tumours with an anti-WT1 antibody, suggesting this may be useful in the diagnosis of these tumours.