图片不清楚，至少要考虑和排查脂肪肉瘤。
Pleomorphic liposarcoma
Definition
● Widespread high grade, pleomorphic tumor cells with some lipoblasts but no evidence of well differentiated liposarcoma
Epidemiology
● 5% of all liposarcomas
● No gender preference
● Median age 54-70 years
● Rare in childhood
● Associated with radiation therapy or neurofibromatosis
Sites
● Thigh (29%), internal trunk (21%), limb girdles (18%), upper extremity (16%), thoracoabdominal wall (10%)
● Often deep seated or extracompartmental
Treatment and prognosis
● Wide local excision or amputation with postoperative radiotherapy (AJSP 2004;28:1257), also chemotherapy
● Aggressive; often recurs locally (40%), metastasizes (40%), causes death (35%)
● 5 year overall survival 60%
● Poor prognostic factors: age 60+, truncal (central) location, deep, size >5 cm, vascular invasion, incomplete excision (AJSP 2002;26:601)
Gross description
● Often large (median 8-10 cm, up to 23 cm), multinodular, white-yellow
● Usually deep (subfascial), often myxoid or necrotic areas
Micro description
● Well circumscribed but non-encapsulated with infiltrative borders
● At least focal typical liposarcomatous areas
● Pleomorphic cells cover > 65% of cut surface with MFH-like, round cell liposarcoma-like (without vascular network), spindle cell liposarcoma-like or epithelioid cells (Mod Path 1999;12:722)
● Usually high grade with enlarged round to bizarre nuclei; tumor necrosis common; median 25 mitotic figures/10 HPF
● May have neutrophils within giant cells, hemangiopericytic foci, extra- and intracellular hyaline droplets
Positive stains
● Vimentin, S100 (lipogenic areas in 33%), smooth muscle actin (45%), CD34, keratin (21%), desmin (13%)
Electron microscopy
● Abundant coalescing lipid droplets, numerous cytoplasmic organelles
Differential Diagnoses
● Dedifferentiated liposarcoma - has well differentiated component
● MFH-pleomorphic - no definite fat vacuoles
● Pleomorphic rhabdomyosarcoma - skeletal muscle differentiation
● Metastatic carcinoma - keratin+ or other evidence of epithelial differentiation, no liposarcomatous differentiation
此外还可以IHC鉴别上皮样肉瘤。
图片不清楚，至少要考虑和排查脂肪肉瘤。
Pleomorphic liposarcoma
Definition
● Widespread high grade, pleomorphic tumor cells with some lipoblasts but no evidence of well differentiated liposarcoma
Epidemiology
● 5% of all liposarcomas
● No gender preference
● Median age 54-70 years
● Rare in childhood
● Associated with radiation therapy or neurofibromatosis
Sites
● Thigh (29%), internal trunk (21%), limb girdles (18%), upper extremity (16%), thoracoabdominal wall (10%)
● Often deep seated or extracompartmental
Treatment and prognosis
● Wide local excision or amputation with postoperative radiotherapy (AJSP 2004;28:1257), also chemotherapy
● Aggressive; often recurs locally (40%), metastasizes (40%), causes death (35%)
● 5 year overall survival 60%
● Poor prognostic factors: age 60+, truncal (central) location, deep, size >5 cm, vascular invasion, incomplete excision (AJSP 2002;26:601)
Gross description
● Often large (median 8-10 cm, up to 23 cm), multinodular, white-yellow
● Usually deep (subfascial), often myxoid or necrotic areas
Micro description
● Well circumscribed but non-encapsulated with infiltrative borders
● At least focal typical liposarcomatous areas
● Pleomorphic cells cover > 65% of cut surface with MFH-like, round cell liposarcoma-like (without vascular network), spindle cell liposarcoma-like or epithelioid cells (Mod Path 1999;12:722)
● Usually high grade with enlarged round to bizarre nuclei; tumor necrosis common; median 25 mitotic figures/10 HPF
● May have neutrophils within giant cells, hemangiopericytic foci, extra- and intracellular hyaline droplets
Positive stains
● Vimentin, S100 (lipogenic areas in 33%), smooth muscle actin (45%), CD34, keratin (21%), desmin (13%)
Electron microscopy
● Abundant coalescing lipid droplets, numerous cytoplasmic organelles
Differential Diagnoses
● Dedifferentiated liposarcoma - has well differentiated component
● MFH-pleomorphic - no definite fat vacuoles
● Pleomorphic rhabdomyosarcoma - skeletal muscle differentiation
● Metastatic carcinoma - keratin+ or other evidence of epithelial differentiation, no liposarcomatous differentiation
此外还可以IHC鉴别上皮样肉瘤。
