Hyperplastic synovium with papillary architecture; sheets of adipocytesÂ
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Chronic inflammation; fibrosis; bone spicules
NB: a reactive, non-neoplastic, process typically arising in the context of osteoarthritis
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Aggregates of foamy macrophages often present
Often associated with HMGA2-rearrangement; many potential partners, including LPP
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with mild variability in size and shape
Peripherally located small monomorphic nuclei
FISH: MDM2 non-amplified
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
FISH: MDM2 non-amplified
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
FISH: MDM2 non-amplified
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Hypocellular collagenous septa
Focal fan necrosis with histiocytic infiltrate
FISH: MDM2 non-amplified
Polygonal cells arranged in sheets and lobules
Ghost outlines of cells with hyalinized membranes
Dystrophic calcification
Histiocytic infiltrate typically present
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Entrapped skeletal muscle fibers may show atrophy, which should not be confused with atypia of liposarcoma
Often associated with HMGA2-rearrangement; many potential partners, including LPP
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Entrapped skeletal muscle fibers may show atrophy, which should not be confused with atypia of liposarcoma
FISH: MDM2 non-amplified
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Interspersed dense paucicellular fibrous septa, which should not be confused with the spindle cells and ropy bands of collagen of spindle cell lipoma
Polygonal cells arranged in sheets and lobules
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Interspersed dense paucicellular fibrous septa, which should not be confused with the spindle cells and ropy bands of collagen of spindle cell lipoma
Sheets of adipocytes
Abundant clear cytoplasm with minimal variability in size and shape
Peripherally located small monomorphic nuclei
Nodules of metaplastic bone; fibrous septa may be broad, but paucicellular