Sandbox:Sara
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Mohsin, M.D.[2]
Microscopic features include:
- Non-circumscribed
- Highly cellular with cells having following characteristics:
- Monomorphic
- Thin
- Spindly
- Scant eosinophilic cytoplasm
- Hyperchromatic nuclei (resembling neurofibroma)
- Tight storiform pattern (cells radiating in spokes at right angles around a central point that often contains a vessel) infiltrating deeply into subcutaneous tissue and entraping fat cells to form a characteristic honeycomb pattern
- Areas of fascicular growth (seen in some cases)
- The early plaque stage may lack the particular storiform pattern
- Many non-atypical mitotic figures may be present
- Non-polarized, thin collagen
- Mild pleomorphism (not significant)
- Focal atypia
- May coexist with giant cell fibroblastoma
- Absent or rare histiocytes
- Following cell types are absent:
- Histiocyte-like cells
- Foam cells
- Giant cells
- Other inflammatory cells
- Different variants include:
- Atrophic (depressed lesion)
- Collagenous (with central thick collagen bundles)
- Granular cell (S100 negative)
- Myxoid
- Palisading
- Pigmented
- Sclerosing