Submit formalin fixed, paraffin-embedded (FFPE) tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

Tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• WT1 is a gene located on chromosome 11p 13 , and is involved in the induction of Wilms' tumor
• The protein encoded by WT1 regulates transcription of other genes, and functions both as a transcriptional activator (with P53) and suppressor (it represses EGF-R and IGF-1R)
• WT1 is expressed in normal mesenchymally derived tissues, included mesothelium, sertoli cells, decidual cells, granulosa cells, pleura, heart, foreskin, endometrium and glomerular epithelium
• This antibody also can be expressed in myelocytic cells and in some leukemias
• It is useful in the identification of mesothelioma, ovarian serous carcinomas, desmoplastic round cell tumors of childhood, certain acute leukemias and extramedullary myeloid tumors, and ovarian and testicular and stromal tumors

Staining pattern

• Nuclear based staining (in Wilms' tumors and malignant mesothelioma)
• Cytoplasmic staining (in some adenocarcinomas and some areas of desmoplastic stroma)
• Perinuclear staining (seen in some tumor cells of malignant mesotheliomas)

References

1. Ordonez NG. Value of TTF1, E-cadherins, BG8, WT1 and CD44S immunostaining in distinguishing epithelial pleural mesothelioma from pulmonary and non-pulmonary adenocarcinoma. Am J Surg Pathol 24(4):598-606, 2000.
2. Foster MR et al: Immunohistochemical analysis of nuclear versus cytoplasmic staining of WT1 in malignant mesotheliomas and primary pulmonary adenocarcinomas. Arch Pathol Lab Med 2001 Oct; 125(10):1316-20.
3. Muir TE et al: Metanephric adenoma, nephrogenic rests and Wilms' tumor: a histologic and immuno-phenotypic comparison. Am J Surg Pathol 2001 Oct; 25(10):1290-6.
4. Sabourin BR et al: Immunohistochemical expression of WT1 by desmoplastic small round cell tumor: a comparative study with other small round cell tumors. Am J Surg Pathol 2000 Jun; 24(6):830-6.
5. Amin KM et al: Wilms' tumor 1 susceptibility (WT1) gene products are selectively expressed in malignant mesothelioma. Am J Pathol 1995 Feb; 146(2):344-56.
6. Lee BH et al: WT1, estrogen receptor, and progesterone receptor as markers for breast or ovarian primary sites in metastatic adenocarcinoma to body fluids. Am J Clin Pathol 2002 May; 117(5):745-50.
7. Hecht JL et al: The value of WT1 in cytologic preparations as a marker for malignant mesothelioma. Cancer Cytopathol 2002; 96:105-9.