Sorted By Test Name - Mayo Medical Laboratories

FMNB
61239
PNEFS
some patients with neuroblastoma
Interpretation: MYCN gene amplification is detected when the percent of cells with an abnormality
exceeds the normal cutoff for the MYCN probe. A positive result is consistent with MYCN gene
amplification. A negative result suggests no MYCN gene amplification. However, this result does not
exclude the diagnosis of neuroblastoma. Specimens will be considered within normal limits if they have
an MYCN-to-D2Z1 ration of 1.00 to 2.00, which indicates there are an equal number of copies of the
MYCN oncogene and the centromere 2. Specimens are considered amplified if they have a ratio of > or
=4.00.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Ambros PF, Ambros IM, SIOP Europe Blastoma Pathology, Biology, and
Bone Marrow Group: Pathology and biology guidelines for resectable and unresectable neuroblastic
tumors and bone marrow examination guidelines. Med Pediatr Oncol 2001 Dec;37(6):492-504 2. Spitz R,
Hero B, Skowron M, et al: MYCN-status in neuroblastoma: characteristics of tumours showing
amplification, gain, and non-amplification. Eur J Cancer 2004 Dec;40(18):2753-2759 3. Valent A, Le
Roux G, Barrois M, et al: MYCN gene overrepresentation detected in primary neuroblastoma tumour
cells without amplification. J Pathol 2002 Dec;198(4):495-501 4. Schwab M: Amplified MYCN in human
neuroblastoma: paradigm for the translation of molecular genetics to clinical oncology. Ann NY Acad Sci
2002 Jun;963:63-73
Neuroblastoma, 2p24 (MYCN) Amplification, FISH, Blood or
Bone Marrow
Clinical Information: Neuroblastoma is a small blue cell tumor that occurs typically in early
childhood and is usually found in the adrenal glands, but rarely is found in other areas of the body.
Approximately 25% of all neuroblastomas have amplification of the MYCN oncogene, located on
chromosome 2 at p24. Amplification of the MYCN oncogene correlates with an unfavorable prognosis
and aggressive disease. Since metastasis to the bone marrow is common, detection of MYCN
amplification in tumor cells present in the bone marrow is important. Prior to ordering this bone marrow
test, if possible, testing on the primary tumor sample should be performed. If the primary tumor tests
negative for MYCN amplification, bone marrow testing is not indicated. If the primary tumor
demonstrates MYCN amplification, identification of MYCN amplification in the bone marrow will
confirm the presence of metastatic disease. In some cases, the diagnostic biopsy specimen from the
primary tumor is small and insufficient specimen may be available for ancillary tests such as FISH. In
addition, if the primary sample is a bone biopsy, it cannot be used for FISH analysis. In such cases, if
metastatic disease involving the bone marrow is identified, FISH testing on the bone marrow can be
performed to evaluate for MYCN status in the tumor.
Useful For: Aids in identifying metastatic disease in patients with a neuroblastoma that has been
previously determined to be positive for the MYCN oncogene
Interpretation: A neoplastic clone is detected when the percent of cells with an abnormality exceeds
the normal cutoff for any given probe. The presence of a positive clone supports a diagnosis of metastatic
disease. The absence of an abnormal clone does not rule out the presence of metastatic disease.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Van Noesel MM, Versteeg R: Pediatric neuroblastomas: genetic and
epigenetic ‘Danse Macabreâ€. Genes 2004;325:1-15 2. Ambros PF, Ambros IM, Brodeur GM, et al:
International consensus for neuroblastoma molecular diagnostics: report from the International
Neuroblastoma Risk Group (INRG) Biology Committee. Br J Cancer 2009;5:471-482
Neuroimmunology Antibody Follow-up, Serum
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