6] Liposarcoma often originates in retroperitoneal mesenchymal tissues, especially in the peri-renal area and is filled with lipoblast
, giant cells, mitoses, and necrosis were absent.
A diagnosis of low-grade liposarcoma was excluded in our case on the basis of an absence of several elements: lipoblasts
, nonlobular architecture, a spindle-cell component, mitotic activity, and cellular pleomorphism.
These changes if extensive can mimic a liposarcoma; however, frank liposarcoma of the colon is extremely rare and requires the presence of lipoblasts
Histologically, these tumors show lipoblasts
(irregularly shaped cells with hyperchromatic nuclei) and lipocytes.
The presence of lipoblasts
is the key finding in this diagnosis.
3] These lipoid cells resemble lipoblasts
, as they have several large intracellular vacuoles (Fig.
Histopathology with H&E stain showed lipoblasts
with vacuolated cytoplasm and hyperchromatic, large, round to oval nuclei and atypical pleomorphic mesenchymal cells in a prominent myxoid stroma and scattered adipocytes.
Microscopically, the tumour was composed of adipocytes of varying sizes including univacuolated and multivacuolated lipoblasts
with a large hyperchromatic nucleus (Figure 2).
2) Histologically, both forms are composed of lipoblasts
, a plexiform capillary network, and myxoid stroma.
4) Myxoid liposarcoma, on the other hand, can be much more cellular and contain numerous stellate to spindled cells as well as characteristic lipoblasts
Benign lipomas can be distinguished from well-differentiated liposarcomas because the former lack atypical lipocytes, lipoblasts
, and cytologic evidence of pleomorphism, and because they are encapsulated and noninvasive.