Comparison of Chromogenic In Situ Hybridization and Fluorescence In Situ Hybridization for the Evaluation of MDM2 Amplification in Adipocytic Tumors.

[dedifferentiated liposarcoma]

Atypical lipomatous tumor /well-differentiated liposarcoma (ALT -WDLPS ) and dedifferentiated liposarcoma (DDLPS ) are characterized cytogenetically by a 12 q 13 -15 amplification involving the mouse double minute 2 (MDM 2 ) oncogene . Fluorescence in situ hybridization (FISH ) is used frequently to detect this amplification and aid with the diagnosis of these entities , which is difficult by morphology alone . Recently , bright-field in situ hybridization techniques such as chromogenic in situ hybridization (CISH ) have been introduced for the determination of MDM 2 amplification status .The present study compared the results of FISH and CISH for detecting MDM 2 amplification in 41 cases of adipocytic tumors . Amplification was defined in both techniques as a MDM 2 /CEN 12 ratio of 2 or greater .Eleven cases showed amplification with both FISH and CISH , and 26 cases showed no amplification with both methods . Two cases had discordant results between CISH and FISH , and two cases were not interpretable by CISH .CISH is advantageous for allowing pathologists to evaluate the histologic and molecular alterations occurring simultaneously in a specimen . Moreover , CISH is found to be more cost- and time-efficient when used with automation , and the signals do not quench over time . CISH technique is a reliable alternative to FISH in the evaluation of adipocytic tumors for MDM 2 amplification .

Diseases
Validation

Diseases presenting "lipomatous tumor" symptom

dedifferentiated liposarcoma

liposarcoma

pleomorphic liposarcoma

well-differentiated liposarcoma

This symptom has already been validated