Get in touch
Our Client Services team is on hand to help. Please call us at 866.776.5907, Option 3.
Eosinophilia FISH Panel
- FISH
This panel is designed to detect key genetic abnormalities associated with lymphoid and myeloid neoplasms characterized by eosinophilia. It includes the following probes:
PDGFRa, CHIC2, FIP1L1 (4q12)
PDGFRb (5q33)
FGFR1 (8p11)
CBFB (16q22)
Test Customization: Probes may be ordered separately.
Clinical Significance
The eosinophilia FISH panel is used to aid in the diagnosis of myeloid and lymphoid neoplasms with eosinophilia and prediction of therapeutic response. The clinical and morphologic features of these diseases can overlap, but each mutation has a characteristic presentation. FIP1L1-PDGFRA rearrangement is generally found in CEL, but the presentation can be as AML, T-lymphoblastic lymphoma, or both simultaneously. Rearrangement is usually cryptic by routine cytogenetics.
Myeloid neoplasms with PDGFRB usually present as chronic myelomonocytic leukemia, but may also present as atypical chronic myeloid leukemia (aCML), CEL, MPN with eosinophilia, AML and juvenile myelomonocytic leukemia (JMML). Myeloid and lymphoid neoplasms with FGFR1 are generally aggressive and may present as MPN, AML, T- or B-LBL/ALL, or mixed phenotype acute leukemia.
PDGFRA and PDGFRB mutations predict responsiveness to tyrosine kinase inhibitors, but MPN with FGFR1 rearrangement do not respond to imatinib and there is no currently established TKI therapy, although some promising new therapies have been reported. AML with inversion 16 may present with less than 20% blasts and can be a subtle abnormality by conventional cytogenetics, so confirmation with FISH is recommended.
Myeloid neoplasms with PDGFRB usually present as chronic myelomonocytic leukemia, but may also present as atypical chronic myeloid leukemia (aCML), CEL, MPN with eosinophilia, AML and juvenile myelomonocytic leukemia (JMML). Myeloid and lymphoid neoplasms with FGFR1 are generally aggressive and may present as MPN, AML, T- or B-LBL/ALL, or mixed phenotype acute leukemia.
PDGFRA and PDGFRB mutations predict responsiveness to tyrosine kinase inhibitors, but MPN with FGFR1 rearrangement do not respond to imatinib and there is no currently established TKI therapy, although some promising new therapies have been reported. AML with inversion 16 may present with less than 20% blasts and can be a subtle abnormality by conventional cytogenetics, so confirmation with FISH is recommended.
Specimen Requirements
Bone Marrow Aspirate: 1-2 mL in sodium heparin tube. EDTA tube is acceptable.
Peripheral Blood: 2-5 mL in sodium heparin tube. EDTA tube is acceptable.
Fresh, Unfixed Tissue: Tissue in RPMI.
Bone Marrow/Peripheral Blood Smear or Fresh Tissue Touch Preparation Slides: Minimum 4 slides, labeled with specimen type.
Fluids: Mix in equal parts with RPMI (specimen volume to RPMI ratio of 1:1).
Fixed Cell Suspension: A client-prepared fixed cell suspension is acceptable if received in 3:1 Methanol:Glacial Acetic Acid.
Storage and Transportation
Use cold pack for transport, making sure cold pack is not in direct contact with specimen. For fresh samples: refrigerate before shipping and ship same day as drawn whenever possible. Do not freeze. NYS clients please provide date and time of Collection.
CPT Code(s)*
88374x4 automated. Codes may differ if manual analysis is performed.
*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.
Last Updated: August 27, 2025