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

If requested, an interpretive report will be provided

Specifications

• A monoclonal antibody that recognizes a specific tyrosine kinase receptor, formed by the t(2,5) translocation called anaplastic lymphoma kinase (ALK)
• The t(2,5) translocation forms a truncated protein NPM-ALK or p80, which is found in many cases of Anaplastic Large Cell Lymphoma (nuclear, nucleolar, and cytoplasmic staining)
• Rare cases of Anaplastic Large Cell Lymphoma associated with trans-locations involving 2 p23 but genes other than NPM also express this antibody (cytoplasmic restricted staining)
• A new type of Large B Cell Lymphoma recently described can express the full length ALK protein (cytoplasmic staining)
• ALK-1 does not label normal lymphoid tissue
• Rare reactivity with CNS system to ALK has been detected on frozen sections

 Staining patterns

• Most Anaplastic Large Cell Lymphomas show cytoplasmic, nuclear, and often nucleolar staining (80% of cases)
• Rare cases of Anaplastic Large Cell Lymphoma without NPM protein expression show cytoplasmic staining only (since the ALK associated protein is not trans-located to the nucleus)
• A recently described subset of Large B Cell Lymphomas (lack t(2,5) and CD 30) exhibit cytoplasmic staining and express the full length ALK protein

References

1. Benharroch D, et al. ALK-Positive Lymphomas, a Single Disease with a Broad Spectrum of Morphology. Blood, Vol. 91, No. 6, 2076-2084, 1998.
2. Pittaluga S, et al. The Monoclonal Antibody ALK-1, Identifies a Distinct Morphological Subytpe of Anaplastic Large Cell Lymphoma Associated with 2p23/ALK Rearrangements. Am J Path 151: 343-351, 1997.
3. Delsol G, et al. A New Subtype of Large B Cell Lymphoma Expressing the ALK Kinase and lacking the 2;5 Translocation. Blood, Vol. 89, No. 5, 1483-1490, 1997.
4. Pulford K, et al. Detection of Anaplastic Lymphoma Kinase (ALK) and Nucleolar Protein Nucleophosmin (NPM) – ALK Proteins in Normal and Neoplastic Cells. The Monoclonal Antibody ALK-1. Blood, Vol. 89, No. 4, 1394-1404, 1997.
5. Chan, John: Anaplastic Large Cell Lymphoma: Redefining its Morphologic Spectrum and Importance of Recognition of the ALK-Positive Subset. Blood, Vol. 91, 2076-84, 1998.
6. Cook, JR et al. Anaplastic Lymphoma Kinase (ALK) expressions in the inflammatory Myo-fibroblastic tumor; a comparative Immunohistochemical study. Am J Surg Pathol 25(11): 1364-1371, 2001.