Myxoid Liposarcoma
Differential Diagnosis
- Lipomatous tumors
- Other myxoid neoplasms
- Small round blue cell tumors
| Myxoid Liposarcoma | Lipoblastoma / Lipoblastomatosis |
|---|---|
| Maturation if present, occurs towards periphery | Maturation if present, occurs towards center of lobules |
| Rare <20, very rare <10 | Very rare >20, rare >10 |
| May have hypercellular areas | Uniformly hypocellular |
| Virtually always deep | May be superficial or deep |
| t(12;16) or t(12;22) | Abnormalities involving 8q(11-13) |
| Myxoid Liposarcoma | Spindle Cell Lipoma with Myxoid Stroma |
|---|---|
| Infrequent prominent spindle cell component | Prominent spindle cell component |
| Prominent "chicken wire" vascular pattern | Lacks "chicken wire" vascular pattern |
| No dense collagen bundles | Dense collagen bundles |
| Very rare in subcutis or dermis | Usually in subcutis or dermis |
| CD34 negative or scattered small cells | CD34 widely positive |
| t(12;16) or t(12;22) | Frequent abnormalities of chromosomes 13 or 16 |
| Myxoid Liposarcoma | Atypical Lipomatous Tumor |
|---|---|
| No large atypical nuclei | Large atypical nuclei present |
| Prominent "chicken wire" vascular pattern | Lacks "chicken wire" vascular pattern |
| Rare as a primary lesion in retroperitoneum | Frequently occurs in retroperitoneum |
| MDM2 and CDK4 4% by immunohistology but 1/5 MDM2 by FISH | MDM2 and CDK4 most positive |
| Myxoid Liposarcoma | Chondroid Lipoma |
|---|---|
| No chondroid matrix | Chondroid matrix |
| Prominent "chicken wire" vascular pattern | Lacks "chicken wire" vascular pattern |
| Cells more uniform | Cells frequently variable in size |
| Myxoid Liposarcoma | Myxolipoma / Angiomyxolipoma |
|---|---|
| Prominent "chicken wire" vascular pattern | Lacks "chicken wire" vascular pattern |
| May have lipoblasts | Lacks lipoblasts |
| Very rare in subcutis or dermis | Usually in subcutis or dermis |
| CD34 negative or scattered small cells | CD34 widely positive in myxoid areas |
| t(12;16) or t(12;22) | t(7;13) or t(8;12) reported |
| Myxoid Liposarcoma | Hibernoma with Myxoid Stroma |
|---|---|
| Rarely superficial | Frequently superficial |
| Prominent "chicken wire" vascular pattern | Lacks "chicken wire" vascular pattern |
| t(12;16) or t(12;22) | 11q13 rearrangement |
| Myxoid Liposarcoma | Aggressive Angiomyxoma |
|---|---|
| Arborizing vessels | Large, disorganized vessels |
| Signet ring lipoblasts | Lacks lipoblasts |
| Myxoid Liposarcoma | Intramuscular Myxoma |
|---|---|
| Arborizing vascular pattern | Hypovascular |
| Lipoblasts present, usually signet ring type | No lipoblasts |
| More cellular | Extremely paucicellular |
| Myxoid Liposarcoma | Juxta-articular Myxoma |
|---|---|
| Lipoblasts present, usually signet ring type | No lipoblasts |
| Arborizing vascular pattern | Hypovascular |
| Myxoid Liposarcoma | Myxofibrosarcoma |
|---|---|
| Lipoblasts frequent | No lipoblasts |
| Vacuoles in lipoblasts are clear | Vacuoles, if present, contain material similar to adjacent myxoid stroma |
| Lacks pleomorphic cells | At least focally pleomorphic |
| Rare in subcutis | Frequent in subcutis |
| t(12;16) or t(12;22) | No consistent abnormalities |
| Myxoid Liposarcoma | Extraskeletal Myxoid Chondrosarcoma |
|---|---|
| Lipoblasts frequent | No lipoblasts |
| Arborizing vasculature pattern | Lacks arborizing pattern |
| Cords of cells unusual | Usually clusters and cords of cells |
| t(12;16) or t(12;22) | t(9;22) or t(9;17) |
| Pure Cellular Myxoid Liposarcoma | Small Round Blue Cell Tumors (Various) |
|---|---|
| Lipoblasts frequent | No lipoblasts |
| Lacks significant pleomorphism | May be pleomorphic |
| No immunologic evidence of differentiation | Specific markers may be positive |
| t(12;16) or t(12;22) | Specific translocations may be present |
