Clinical Features:

• More common in the deep soft tissues; subcutaneous examples are rare
• Most commonly seen in the lower limb of adults
• Tends to recur
• Metastases occur in approximately one third of cases
• Round cell liposarcoma is part of the spectrum of myxoid liposarcoma, and the presence of a round cell component is an adverse prognostic marker.

Histologic Features:

• Uniform stellate to spindled cells in a myxoid background
• The cells contain small vacuoles with rare mitoses
• Occasional lipoblasts can be seen, most commonly at the periphery of the tumor.
• The most characteristic and specific diagnostic feature is the universally present network of abundant small, curvilinear, branching capillaries, described as having a "chicken wire" or "crow's foot" appearance.  The absence of these vessels effectively rules out the diagnosis of myxoid liposarcoma.
• Pools of mucin, sometimes resembling lymphangioma, are often present.
• Round cell change is the term used for more cellular areas with round to oval hyperchromatic nuclei and high nuclear:cytoplasmic ratios
  • Round cell change is associated with a more aggressive course and less favorable prognosis.
  • Tumors with both myxoid and round cell areas are known as either combined myxoid and round cell liposarcoma or high-grade myxoid liposarcoma.
  • Pure round cell liposarcomas are extremely rare in the subcutis.

Cases associated with this book:

Myxoid liposarcoma
Author: Artur Zembowicz M.D. Ph.D.

Conference: DermatopathologyConsultations.com Teaching Collection