Retained heterodisomy for chromosome 12 in atypical lipomatous tumors: implications for ring chromosome formation

2004 ◽  
Vol 106 (1) ◽  
pp. 33-38 ◽  
Author(s):  
F. Mertens ◽  
I. Panagopoulos ◽  
T. Jonson ◽  
D. Gisselsson ◽  
M. Isaksson ◽  
...  
2016 ◽  
Vol 140 (10) ◽  
pp. 1111-1115 ◽  
Author(s):  
Gloria Zhang ◽  
Christopher P. Lanigan ◽  
John R. Goldblum ◽  
Raymond R. Tubbs ◽  
Erinn Downs-Kelly

Context.—Atypical lipomatous tumors/well-differentiated liposarcomas contain alterations in the 12q13-15 region resulting in amplification of MDM2 and nearby genes. Identifying MDM2 amplification is a useful ancillary test, as the histologic mimics of atypical lipomatous tumors/well-differentiated liposarcomas have consistently shown a lack of MDM2 amplification. Objective.—To assess the interobserver reproducibility of a bright-field assay for MDM2 amplification (dual-color, dual-hapten in situ hybridization [DDISH]) among reviewers with varying degrees of experience with the assay and to assess the concordance of MDM2 DDISH with MDM2 fluorescence in situ hybridization (FISH). Design.—In total, 102 cases were assessed in parallel for MDM2 by FISH and DDISH. MDM2 amplification was defined as an MDM2 to chromosome 12 ratio of 2.0 or greater, whereas an MDM2 to chromosome 12 ratio of less than 2 was nonamplified. Fluorescence in situ hybridization was scored in the routine clinical laboratory and DDISH was evaluated by 3 different pathologists blinded to the final diagnosis and FISH results. Results.—Fluorescence in situ hybridization categorized 27 cases (26%) as MDM2 amplified and 75 cases (74%) as nonamplified; the consensus DDISH diagnosis was 98% concordant with FISH. Agreement between MDM2 DDISH by each reviewer and MDM2 FISH was highly concordant (99%, 98%, and 98%, respectively, for reviewers 1, 2 and 3). The κ agreement of the 3 reviewers scoring DDISH was excellent (κ = 0.949, 0.95, and 0.95, respectively, for reviewers 1, 2, and 3). Conclusions.—This study highlights excellent concordance between DDISH and FISH in MDM2 copy number assessment. Moreover, excellent interobserver reproducibility of the DDISH assay was found among reviewers with varying levels of experience evaluating bright-field assays.


2009 ◽  
Vol 48 (11) ◽  
pp. 993-1001 ◽  
Author(s):  
Domenico Trombetta ◽  
Fredrik Mertens ◽  
Angelo Lonoce ◽  
Pietro D'Addabbo ◽  
Karin Rennstam ◽  
...  

2008 ◽  
Vol 66 (2) ◽  
pp. 366-369 ◽  
Author(s):  
Jason DeWitt ◽  
Joseph Heidelman ◽  
Don-John Summerlin ◽  
Charles Tomich

1993 ◽  
Vol 8 (2) ◽  
pp. 69-73 ◽  
Author(s):  
Jeffrey R. Sawyer ◽  
Gael Sammartino ◽  
M. Husain ◽  
Jane M. Lewis ◽  
Bruce Anderson ◽  
...  

2008 ◽  
Vol 132 (6) ◽  
pp. 952-957
Author(s):  
Carlynn Willmore-Payne ◽  
Joseph Holden ◽  
Kristi C. Turner ◽  
Alan Proia ◽  
Lester J. Layfield

Abstract Context.—Liposarcomas display a number of molecular abnormalities involving chromosome 12. Myxoid and round cell liposarcomas are characterized by t(12;16)(q13; p11) or t(12;22)(q13;q12) translocations. Amplifications occur within the 12q13-15 region of atypical lipomatous tumors and well-differentiated liposarcomas but not lipomas. Objective.—To investigate the performance characteristics of the LSI CHOP Breakapart Rearrangement Probe for the diagnosis of myxoid/round cell liposarcomas and atypical lipomas/well-differentiated liposarcomas. Design.—We investigated a series of lipomatous neoplasms (5 lipomas, 5 well-differentiated liposarcomas, 22 myxoid/round cell liposarcomas, 2 liposarcomas not otherwise specified, and 2 dedifferentiated liposarcomas) and normal myometrium for abnormalities in the q13-15 region of chromosome 12. Cases were studied for the presence or absence of t(12;16)(q13;p11) or t(12;22)(q13;q12) translocations by the LSI CHOP Breakapart Rearrangement Probe. These probes contain a sequence encompassing the SAS and CDK4 genes. Four or more copies of this sequence were considered to represent amplification of these genes. Results.—Rearrangement of the CHOP gene was seen in all evaluable myxoid liposarcomas. Rearrangements were seen in 1 dedifferentiated liposarcoma but not in normal myometrium or lipomas. Probe signal amplification was seen in all 5 well-differentiated liposarcomas and 1 myxoid liposarcoma. No signal amplification was seen in lipomas or myometrium. Conclusions.—Demonstration of translocations t(12; 16)(q13;p11) and t(12;22)(q13;q12) by the LSI CHOP Breakapart Rearrangement Probe appears to correlate with round cell/myxoid liposarcoma. The probe also demonstrated amplification of the 12q13-15 region in well-differentiated liposarcomas, making it useful for the diagnosis of these neoplasms. In a significant percentage of cases, high background fluorescence or poor probe staining made interpretation difficult.


2000 ◽  
Vol 8 (3) ◽  
pp. 222-227 ◽  
Author(s):  
Cary D. Austin ◽  
Jon R. Tiessen ◽  
Anuradha Gopalan ◽  
Jesse M. Williams ◽  
Charles D. Bangs ◽  
...  

2007 ◽  
Vol 15 (5) ◽  
pp. 548-555 ◽  
Author(s):  
Jeroen Knijnenburg ◽  
Arie van Haeringen ◽  
Kerstin B M Hansson ◽  
Arjan Lankester ◽  
Margot J M Smit ◽  
...  

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