Submit a formalin-fixed, paraffin embedded tissue block

Formalin-fixed, paraffin embedded (FFPE) tissue block

Tissue section mounted on a charged, unstained slide

Ambient (preferred)

Immunohistochemical staining and microscopic examination

An interpretive report will be provided

Ventana ALK (clone D5F3)

• FDA approved test, only for testing in lung adenocarcinomas and non-small cell carcinomas NOS to evaluate for eligibility for ALK targeted therapy
• Note there are two IHC stains available labeled ALK. ALK1 Lymphoma IMT & ALK therapeutic. The ALK1 Lymphoma IMT should be used for lymphomas and inflammatory myofibroblastic tumor work-ups only. ALK therapeutic is used for stage IV lung adenocarcinomas and non-small cell carcinomas NOS

Specifications

• The incidence of ALK gene rearrangements in lung adenocarcinomas is estimated to range from 2-7%
• The anaplastic lymphoma kinase (ALK) protein is a member of the insulin receptor superfamily of receptor tyrosine kinases
• ALK is a type I membrane glycoprotein that is normally expressed only in the nervous system
• ALK resides at chromosome 2p23 and is constructed mainly of 2 large introns and 26 exons
• ALK resides at chromosome 2p23 and is constructed mainly of 2 large introns and 26 exons
• The molecular pathogenesis of ALK begins with chromosomal rearrangements that partner the 3' coding sequences for the intracellular signaling domain with 5' promoter elements and coding sequences of other genes

Staining pattern

• Positive staining: Strong granular cytoplasmic staining in one or more tumor cells. The corresponding H&E stained section should be reviewed concurrently with the ALK IHC stained slide

Known staining artifacts

1. Nonspecific background staining: Approximately 1-2% of cases will demonstrates weak, diffuse granular cytoplasmic pattern which is above the background staining present on the negative control slide
2. Granular cytoplasmic staining in normal tissue elements including alveolar macrophages, benign glandular epithelial cells and neuronal tissue elements
3. Non-specific staining of background mucin

References

1. Roche Ventana ALK (D5F3) CDx Assay Interpretation Guide for non-small cell lung carcinoma (NSCLC). www.ventana.com.