When Is Immunohistochemistry Useful in Assessing Tumor Necrotic Tissue?

Background/aim Immunohistochemistry (IHC) enables visualisation of the distribution of specific proteins, the differentiation of benign and malignant tumours, and the site and origin of a primary tumour. Surgical pathologists commonly examine tumours with extensive necrosis or non-viable tissue that may affect an accurate diagnosis. Materials and methods We investigated the sensitivity and specificity of IHC on necrotic samples derived from adenocarcinoma, squamous cell carcinoma (SCC) and melanoma using different markers. Results Analysis of necrosis within tumours revealed 88% sensitivity and 56% specificity for melanoma, 95% and 92% for CK5/6, 95% and 83% for CK20, 37% and 95% for p63, 69% and 97% for Melan A, 88% and 92% for SOX-10, 98% and 56% for CKAE/AE3 and 75% specificity for CK7. Conclusion Antibodies should be considered reliable markers for demonstrating the epithelial nature of a suspected tumour. Immunohistochemistry of necrotic tissues may provide clinically useful information.