Liposarcoma is a malignant tumour composed entirely or in part of neoplastic adipocytes.
There are five variants that differ in morphology, clinical manifestation, genetic profile and prognosis:
|Well differentiated liposarcoma
/ Atypical lipomatous tumour||40-50%||Adults; peak 6th decade||Limbs (thigh), retroperitoneum, paratesticular area, mediastinum||Only after dedifferentiation
(<10% of cases)||Supernumerary ring and giant marker chromosomes, MDM2 amplification|
||<10%||Adults||Retroperitoneum, limbs||Yes, in 15-20% of cases||Supernumerary ring and giant marker chromosomes; multiple abnormal clones|
/Round cell liposarcoma||30-35%||Peak 4th-5th decade||Musculature of the thigh; deep soft tissues (limbs)||Yes, in approx. 1/3 of cases||Translocation t(12;16)(q13;p11) in 90% of cases|
||Approx. 5%||Adults > 50 years||Lower limbs > upper limbs||Yes, in 30-50% of cases||Complex rearrange-ments, with ring, giant marker and double minute chromosomes|
||Very rare||> 60 years||Retroperitoneum, abdomen||Yes||Ring and giant marker chromosomes, 12q14-15 amplification (MDM2)|
Primary liposarcoma of the breast affects predominantly women from 19-76 years of age (median, 47 years); male patients are rare. The tumour typically presents as a slowly enlarging, painful mass with a median size of 8 cm. Practically all variants of soft tissue liposarcoma may occur in the breast
Austin RM, Dupree WB (1986)
. The tumour behaves particularly aggressively when associated with pregnancy
Liposarcoma of the breast: a clinicopathologic study of 20 cases.
Hum Pathol 17: 906-13
Tavassoli FA, Devilee P (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Breast and Female Genital Organs.
IARC Press: Lyon 2003