Cytogenetic and molecular genetic analyses of liposarcoma and its soft tissue simulators: recognition of new variants and differential diagnosis.
Liposarcoma is one of the most common sarcomas of adults. Its differential diagnosis and accurate subclassification are often problematic; the latter is also important with regard to appropriate treatment and prognosis. We studied a series of 23 liposarcomas that had unusual or previously undescribed features and 10 liposarcoma simulators and correlated the morphologic, cytogenetic, and molecular genetic findings. We found that use of cytogenetic-molecular genetic techniques aids in the distinction between myxoid-round cell liposarcoma and their simulators, chondroid lipoma, myxoid spindle cell-pleomorphic lipoma, cellular intramuscular myxoma, and myxofibrosarcoma. Poorly differentiated forms of round cell liposarcoma lacking morphologic evidence of lipogenesis can also be diagnosed using these techniques; however, the techniques do not aid in distinguishing low-grade myxoid from high-grade round cell liposarcomas. This study also shows that retroperitoneal liposarcomas with myxoid liposarcoma-like zones are part of the morphologic spectrum of well-differentiated-dedifferentiated liposarcoma rather than true myxoid liposarcomas. Perhaps most importantly, our results provide the first molecular genetic evidence that true mixed liposarcomas (mixed well-differentiated and myxoid liposarcoma) do indeed exist. They also unequivocally demonstrate the existence of small, round cell variants of pleomorphic liposarcoma that closely simulate myxoid-round cell liposarcoma.
Meis-Kindblom
J M
JM
Department of Pathology and the Musculoskeletal Tumor Center, Göteborg University, Sahlgrenska University Hospital, Sweden. jeanne.meis-kindblom@llcr.med.gu.se
Sjögren
H
H
Kindblom
L G
LG
Peydró-Mellquist
A
A
Röijer
E
E
Aman
P
P
Stenman
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015139:Blotting, Southern; D003582:Cytogenetics / Q000379:methods; D017931:DNA Primers / Q000737:chemistry; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D005354:Fibrosarcoma / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008067:Lipoma / Q000175:diagnosis / Q000235:genetics; D008080:Liposarcoma / Q000175:diagnosis* / Q000235:genetics; D018208:Liposarcoma, Myxoid / Q000175:diagnosis / Q000235:genetics; D008297:Male; D008875:Middle Aged; D008967:Molecular Biology / Q000379:methods; D009232:Myxoma / Q000175:diagnosis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000235:genetics
D017931:DNA Primers; D004273:DNA, Neoplasm