Molecular Diagnostics

At Yale Pathology, one of the preeminent areas of application of molecular diagnostic testing is oncology. It is now possible to phenotype and genotype human tumors to increase the accuracy and reproducibility of pathologic diagnosis. Small numbers of malignant cells can be detected in cytological preparations or biopsies through the clinically validated use of molecular markers. The detection of clonally rearranged antigen receptor genes in lymphoid cells is a powerful tool for establishing a lymphoma diagnosis. In addition to establishing primary diagnoses, genotyping can effectively detect minimal residual disease and classify lymphoma subtypes. Somatic genetic alterations of solid tumors have also been found useful in clinical applications. Characteristic mutations can be used as markers for the detection of very small numbers of tumor cells (endoscopic biopsies or fine needle aspirates) to increase the sensitivity and accuracy of pathologic diagnosis. In specific instances (e.g. selected soft tissue and pediatric tumors), specific fusion gene transcripts provide a basis for molecular diagnosis and subclassification. Tissue DNA genotyping has recently been validated at Yale Pathology as a highly practical and cost-effective method for the routine diagnosis and sub-typing of molar pregnancies.

Molecular Diagnostic Tests Frequently Requested:

• Malignant Lymphoma  - Clonal Rearrangement Analysis
• Colon Cancer And Hnpcc - Microsstellite Instability Testing
• Breast Cancer And Herceptin Treatment - Her-2/Neu Testing By FISH
• Glioma Diagnosis And Prognostication - Chromosome 1p19q Deletion By FISH
• Flourence In-Situ Hybridiation In Detection Of Chromosomal Translocation In Various Solid Tumors And Lymphomas
• Tissue DNA Genotyping In Diagnosis And Subtyping Of Hydatidiform Moles