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Search: Organ site Search: Tumor / Syndrome
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WHO Classification of Tumours
Liposarcoma, NOS
Hypopharynx, Larynx and Trachea


Definition

Liposarcoma is a malignant tumor composed entirely or in part of neoplastic adipocytes.
There are five variants that differ in morphology, clinical manifestation, genetic profile and prognosis:
Variant/synonymFraction of liposarcomasAgeLocationMetastasisGenetics
Well differentiated liposarcoma / Atypical lipomatous tumour40-50%Adults; peak 6th decadeLimbs (thigh), retroperitoneum, paratesticular area, mediastinumOnly after dedifferentiation (<10% of cases)Supernumerary ring and giant marker chromosomes, MDM2 amplification
Dedifferentiated liposarcoma <10%AdultsRetroperitoneum, limbsYes, in 15-20% of casesSupernumerary ring and giant marker chromosomes; multiple abnormal clones
Myxoid liposarcoma /Round cell liposarcoma30-35%Peak 4th-5th decadeMusculature of the thigh; deep soft tissues (limbs)Yes, in approx. 1/3 of casesTranslocation t(12;16)(q13;p11) in 90% of cases
Pleomorphic liposarcom Approx. 5%Adults > 50 yearsLower limbs > upper limbsYes, in 30-50% of casesComplex rearrange-ments, with ring, giant marker and double minute chromosomes
Mixed-type liposarcoma Very rare> 60 yearsRetroperitoneum, abdomenYesRing and giant marker chromosomes, 12q14-15 amplification (MDM2)