23) Figure 6, A, depicts a normal interphase nucleus using the EWSR1 break-apart probe.
However in contrast to MM, CCSTA is characterized by the t(12;22)(q13;q12) that leads to the fusion of the ATF1 gene localized to 12q13 to the EWSR1 gene at 22q12 in up to 90% of cases.
Summary of Fluorescence In Situ Hybridization (FISH) Results for Major Morphologic Categories FISH Probes EWSR1, No.
1) Five split-apart probe sets are used at our institution to evaluate most translocations including probes to the EWSR1, FUS, DDIT3, SYT, and FOXO1A genes (Abbott Molecular/Vysis, Des Plaines, Illinois).
A dual color assay using the break apart translocation probe EWSR1
(Ewing sarcoma breakpoint region 1) was performed to look for a rearrangement of the EWSR1
locus at 22q12 because in abnormalities of EWS, translocations are frequently found in Ewing sarcoma/primitive neuroectodermal tumor with the translocation partner typically FLI1, 11Q24, or ERG, 21Q22.
EWSR1 is rearranged in several neoplasms other than the Ewing family of tumors (Table 3).
96,97) This translocation results in the fusion of the EWSR1 gene, located on chromosome 22q12, to a member of the ETS gene family of transcription factors, Fli1, on chromosome 11q24.
For example, although the t(11;22)(q24;q12) is characteristic of Ewing sarcoma/PNET, rearrangement of EWSR1
(22q12) is not confined to Ewing sarcoma but is also seen in most or in smaller subsets of desmoplastic small round-cell tumor, clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and myxoid or round cell liposarcoma, among others.
(Vysis LSI EWSR1
22q12 dual-color break-apart probe, Abbott Molecular, Abbott Park, Illinois) and ATF1 (custom break-apart probe) probes were used for hybridization.
Paraffin sections analysed with Fluorescence In situ Hybridization (FISH) studies of the EWS gene showed a normal signal pattern (two yellow signals) with EWSR1
(Zymed laboratories locus 22q12/ q13) break apart probe in the majority of sites examined consistent with a normal result.
Nearly all EWS begins with a chromosomal rearrangement that fuses part of the EWSR1
gene with a segment of FLI1 or a related gene.
Clinical, radiologic, pathologic, genetic features of PNET/EWS Clinical features Radiologic features PNET/EWS * Flank pain * Large size * Hematuria * Lack of extensive * Abdominal mass parenchyma infiltration * Weight loss * Lack of renal vein invasion * Diffuse large calcification * Internal hemorrhage and necrosis * Peripheral hypervascularity Pathologic features Genetic features PNET/EWS * Presence of * Glycoprotein p30/32 neurosecretory granules (monoclonal antibody) CD99 * Presence of rosettes (encoded by the MIC2 gene) (electron microscopy) or * Specific chromosomal pseudorosettes (light translocations t (11; 22) microscopy) (q24; q12); t (21; 22) * Neuron-specific enolase (q22; q12) EWSR1
gene * Chromogranin A rearrangement * Synaptophysin Table 4.