The MDM2/D12S1837 DNA-FISH Probe is designed to detect both the polyploidy of chromosome 12 and the amplification of  the MDM2 gene located on 12q14.3-q15 relative to the control locus D12S1837 located on 12p11 by fluorescence in situ hybridization (FISH).  MDM2 is frequently amplified in many solid tumor, including soft tissue tumors. Well-differentiated liposarcomas has been found by molecular and cytogenetic studies to contain amplification of the 12q13-15 region, including the MDM2 gene.^[1,2]  Precise recognition of benign lipoma and well-differentiated liposarcoma by core needle biopsy can facilitate appropriate clinical management.^[3]  Trisomy of chromosome 12 (+12) is a commonly observed numerical aberration in non-Hodgkin lymphomas (NHL) cases.  It has been observed in  ~15-50% chronic lymphocytic leukemia (CLL) cases.^[4]  In CLL, trisomy 12, when observed as a sole abnormality, appears to have limited prognostic implications and is often associated with an atypical morphology, although it is only observed in a subset of tumor cells.^[5]