Surgical Pathology Criteria

Dermatofibrosarcoma Protuberans

Differential Diagnosis

Dermal and Deep Fibrous Histiocytoma Dermatofibrosarcoma Protuberans
Usually <1 cm Frequently >2 cm
Haphazard short fascicles in dermal lesions; deep lesions frequently storiform Regular storiform pattern
Infrequent infiltration into and around fat cells Frequent infiltration into and around fat cells
Frequently mixed cell population Monomorphous cell population
Frequent overlying epithelial hyperplasia Overlying epithelium usually attenuated
CD34 40% in deep lesions, negative in dermal lesions CD34 100% extensive
Apolipoprotein D negative (deep lesions not tested) Apolipoprotein D 90%
Factor XIIIa >95% extensive Factor XIIIa 75% but focal and weak
CD34 and Factor XIIIa are difficult to interpret in many cases because of numerous entrapped reactive cells

 

Myxoid Nerve Sheath Tumor Myxoid Dermatofibrosarcoma Protuberans
Areas of typical nerve sheath tumor usually present Areas of typical storiform pattern usually present
S100 positive S100 negative
CD34 may stain scattered dendritic cells but not lesional cells CD34 stains lesional cells

 

Myxoid Liposarcoma Myxoid Dermatofibrosarcoma Protuberans
Usually involves deep soft tissue Usually involves dermis and superficial subcutaneous tissue
Frequently contains lipoblasts No lipoblasts
CD34 may stain scattered dendritic cells but not lesional cells CD34 stains lesional cells

 

Plexiform Fibrohistiocytic Tumor Dermatofibrosarcoma Protuberans
Ray-like extension into surrounding fat Infiltrates between and around individual fat cells
Collagenous stroma Usually contains only fine collagen
Nodules of histiocytes and giant cells in most cases Histiocytes and giant cells very rare
CD34 negative CD34 stains lesional cells
 

 

Desmoplastic Melanoma Dermatofibrosarcoma Protuberans
Lacks storiform pattern Prominent storiform pattern
Displaces or destroys fat Infiltrates between and around individual fat cells
Dense collagenous stroma Usually contains only fine collagen
Frequently contains lymphoid nodules Inflammatory cells infrequent
CD34 negative CD34 stains lesional cells
S100 positive S100 negative

 

Dermatofibrosarcoma Protuberans Adult or Infantile Fibrosarcoma
CD34 positive CD34 negative
Storiform pattern Fascicular, herringbone pattern
Involves dermis and subcutaneous tissue Virtually always in deep soft tissue
DFSP may dedifferentiate with a fibrosarcoma pattern
If fibrosarcoma occurs in the dermis or subcutaneous tissue, it is usually dedifferentiated DFSP

Stanford Medicine Resources:

Footer Links: