Sorted By Test Name - Mayo Medical Laboratories

83367
TFE3
61013
diagnosis of alveolar rhabdomyosarcoma. Lab Invest 2006 Jun;86(6):547-556 3. Ladanyi M. Bridge JA:
Contribution of molecular genetic data to the classification of sarcomas. Hum Pathol 2000
May;31(5):532-538 4. Edwards RH, Chaten J, Xiong QB, Barr FG: Detection of gene fusions in
rhabdomyosarcoma by reverse transcriptase-polymerase chain reaction assay of archival samples. Diagn
Mol Pathol 1997 Apr;6(2):91 5. Lae ME, Roche PC, Jin L, et al: Desmoplastic small round cell tumor: a
clinicopathologic, immunohistochemical, and molecular study of 32 tumors. Am J Surg Pathol 2002
Jul;26(7):823-835
Alveolar Rhabdomyosarcomas (ARMS) by Reverse
Transcriptase PCR (RT-PCR), Paraffin
Clinical Information: Alveolar rhabdomyosarcoma (ARMS) is a member of the family of
rhabdomyosarcomas (tumors composed of cells showing muscle differentiation) that also includes
embryonal, botryoid, spindle cell, and pleomorphic types.(1) Alveolar rhabdomyosarcomas include the
classical and solid patterns.(1) ARMS is also a member the small-round-cell tumor group that includes
synovial sarcoma, lymphoma, Wilms tumor, Ewing sarcoma, and desmoplastic small-round-cell tumor.
While treatment and prognosis depend on establishing the correct diagnosis, the diagnosis of sarcomas
that form the small-round-cell tumor group can be very difficult by light microscopic examination alone,
especially true when only small-needle biopsy specimens are available for examination. The use of
immunohistochemical stains (eg, desmin, actin, and the nuclear transcription factor markers MyoD and
myogenin) are useful in separating rhabdomyosarcomas from other small-round-cell tumors, but do not
always distinguish the various subtypes of rhabdomyosarcomas. Expertise in soft tissue and bone
pathology are often needed. Studies have shown that some sarcomas have specific recurrent chromosomal
translocations. These translocations produce highly specific gene fusions that help define and characterize
subtypes of sarcomas and are useful in the diagnosis of these lesions.(1-4) Most cases of ARMS have a
t(2;13)(q35;q14) reciprocal translocation. This rearrangement juxtaposes 5' portions of the PAX3 gene on
chromosome 2 with 3' portion of the FOXO1A gene on chromosome 13 resulting in a chimeric gene in
the designated chromosome 13 that encodes a transcriptional regulatory protein in 75% of cases.(1)
Another variant t(1;13)(q36;q14) translocation fuses the 5' portion of the PAX7 gene on chromosome 1
with the FOXO1A gene on chromosome 13 in a smaller number of cases (10%). The PAX3-FOXO1A
fusion is associated with a worse prognosis than the PAX7-FOXO1A fusion.
Useful For: Supporting the diagnosis of alveolar rhabdomyosarcoma
Interpretation: A positive result is consistent with a diagnosis of alveolar rhabdomyosarcoma
(ARMS). Sarcomas other than ARMS, and carcinomas, melanomas, and lymphomas are negative for the
fusion products. A negative result does not rule-out a diagnosis of ARMS.
Reference Values:
Negative
Clinical References: 1. Edwards RH, Chatten J, Xiong QB, Barr FG: Detection of gene fusions in
rhabdomyosarcoma by reverse transcriptase polymerase chain reaction assay of archival samples. Diagn
Mol Pathol 1997;6:91-97 2. Ladanyi M, Bridge JA: Contribution of molecular genetic data to the
classification of sarcomas. Hum Pathol 2000;31:532-538 3. Galili N, Davis RJ, Fredricks WJ, et al:
Fusion of a fork head domain gene to PAX3 in the solid tumor alveolar rhabdomyosarcoma. Nat Genet
1993;5:230-235 4. Jin L, Majerus J, Oliveira A, et al: Detection of fusion gene transcripts in fresh-frozen
and formalin-fixed paraffin-embedded tissue sections of soft tissue sarcomas after laser capture
microdissection and RT-PCR. Diagn Mol Pathol 2003;12:224-230
Alveolar Soft Part Sarcoma (ASPS)/Renal Cell Carcinoma
(RCC), Xp11.23 (TFE3), FISH, Tissue
Clinical Information: Alveolar soft-part sarcoma (ASPS) is a rare malignant tumor typically
occurring in patients in their 20s to 30s within the muscle and deep tissues of the extremities. ASPS is
slow growing and refractory to chemotherapy with a propensity to metastasize. Prolonged survival is
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