Acute Myeloid Leukemia (AML), FISH

CPT CODE:

USEFUL FOR:

Detecting a neoplastic clone associated with the common chromosome anomalies seen in patients with AML or other myeloid malignancies
Evaluating specimens in which standard cytogenetic analysis is unsuccessful
Identifying known chromosome anomalies in patients with myeloid malignancies and tracking response to therapy

SPECIMEN REQUIRED:

Please provide a reason for referral with each specimen. The laboratory will not delay or reject testing if this information is not provided, but appropriate testing and interpretation may be compromised.
Submit only 1 of the following specimens:
BloodDraw blood in a green-top (sodium heparin) tube(s), and send7 mL to 10 mL of sodium heparin whole blood. Invert several times to mix blood. (Clotted blood is not acceptable.) Otheranticoagulants are not recommended and are harmful to the viability of the cells. Label vial with patient's name and laboratory control number. Forward promptly at ambient temperature. Specimen cannot be frozen. Advise Express Mail or equivalent if not on courier service.Note:     If ordering electronically, please complete and submit a                   "Cytogenetics Hematologic FISH Panel Patient Information                   Sheet" (Supply T603 or see Special Instructions) with the                   specimen. If not ordering electronically, please complete                   and submit a "Cytogenetics Hematologic Disorders                   Request Form" (Supply T607) with the specimen.
Bone MarrowObtain 1 mL to 2 mL of bone marrow in a green-top (sodium heparin)tube(s). Invert several times to mix bone marrow. (Clotted bonemarrow is not acceptable.) Other anticoagulants are not recommended and are harmful to the viability of the cells. Labelvial with patient's name and laboratory control number. Forwardpromptly at ambient  temperature. Specimen cannot be frozen. Advise Express mail or equivalent if not on courier service.Note:     If ordering electronically, please complete and submit a                   "Cytogenetics Hematologic FISH Panel Patient Information                   Sheet" (Supply T603 or see Special Instructions) with the                   specimen. If not ordering electronically, please complete                   and submit a "Cytogenetics Hematologic Disorders                   Request Form" (Supply T607) with the specimen.

TRANSPORT TEMPERATURE:

Ambient\Refrig OK\Frozen NO

CLINICAL INFORMATION:

Acute myeloid leukemia (AML) is 1 of the most common adult leukemias, with almost 10,000 new cases diagnosed per year. AML also comprises 15% of pediatric acute leukemias and accounts for the majority of infant (<1 year old) leukemias. Several subtypes of AML have been recognized (termed AML-M0, M1, M2, M3, M4, M5, M6, and M7) based on the malignant myeloid cell lineage involved. In addition to morphology, several recurrent chromosomal anomalies have been linked to specific subtypes of AML. The most common chromosome anomalies associated with AML include t(8;21), t(15;17), inv(16), 8, inv(3), t(6;9), t(8:16), t(3:21) and anomalies of the MLL geneat 11q23, particularly t(9;11). These recurrent chromosome anomaliesare identified in approximately 60% of AML cases.
Conventional chromosome analysis is the gold standard for identification of the common recurrent chromosome anomalies, in addition to the less common anomalies. However, this analysis requires dividing cells, takes approximately 7 days to process, and some of the subtle rearrangements can be missed (eg, inv[16], MLLanomalies). Thus, we have validated a combination of commerciallyavailable and Mayo in-house developed FISH probes to detect thecommon chromosome anomalies observed in AML patients. Theseprobes have diagnostic and prognostic relevance and can also beused to track response to therapy.

CLINICAL INTERPRETATION:

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for any given probe.
Detection of an abnormal clone likely indicates a diagnosis of an AML of various subtypes.
The absence of an abnormal clone does not rule out the presence of a neoplastic disorder.

REFERENCE VALUES:

An interpretive report will be provided.