Angiomyofibroblastoma

Myxoid Leiomyosarcoma

Cellular/Round Cell Liposarcoma

Myxoid Liposarcoma

Hyalinizing Spindle Cell Tumor with Giant Rosettes

Fibromyxoid Sarcoma

Myxofibrosarcoma

Acral Myxoinflammatory Fibroblastic Sarcoma

Extraskeletal Myxoid Chondrosarcoma

Mesenchymal Chondrosarcoma

Intramuscular/Juxta-Articular Myxoma

Cutaneous Myxoma

Aggressive Angiomyxoma

Ossifying Fibromyxoid Tumor

Mixed Tumor

Nerve Sheath Tumor

Myxoid Spindle Cell Lipoma

Myxoid Neurofibroma

Myxoid DFSP

Hypovascular

No pleomorphism

Paucicellular

Lipoblasts

Chicken-wire vessels

  Small curving radius

Thicker vessels

  Wider curving radius

Vacuolated cells lack lipid

Pleomorphic

Stellate/tripolar cells

Keratin positive

Epithelial-like cytomorphology

Sometimes ducts

HPC with cartilaginous differentiation

S-100 stains chondroid element

May be CD99 positive

More solid fibrous areas

More mixed inflammatory infiltrate

Reed-Sternberg-like cells

Superficial

Fibrous areas

Whorled, bland

More vascular

More uniformly myxoid

More nuclear hyperchromasia & polymorphism

Myxoid

Differential

Map

Giant rosettes

Rosettes– large, collagenized

  core

Remainder– small spindle

  cells, random or storiform

Wavy nuclei

Intratumoral axons

S-100 positive

Lipoblasts

Vessels– more

   abundant, branching,

   delicate

Malignant chondrocytes

No cytoplasmic fat vacuoles

No prominent vasculature

Fibrous septa

Hyaluronidase resistant

Thick collagen bundles

CD34 positive

Lipoblasts, pleomorphism

Plexiform vascular pattern

Nodular Fasciitis

Pleomorphism

Prominent vasculature

Slit-like spaces

Extravasated erythrocytes

Keloid-like collagen

Larger, deeper

Lipoblasts

Plexiform vascularity

Metaplastic bone

Most S-100+, 50% desmin +, rare focal CK+

CK+

Lobular

Neutrophils

Larger, deeper

Usu. female pelvic

Vascular pattern

Desmin+ estrR+ progR+

Wavy nuclei

S-100 positive

More vascular

Large size

Infiltrating border

Thick rounded vessels

FUS-CREB3L2 fusion

t(7;16)(q33:p11)

90%

EWSR1-NNR4A3 fusion

t(9;22)(q22:q12)

Also t(9:17)

FUS– CHOP fusion

t(12;16)(q13;p11)

Also t(12:22)