Surgical Pathology Criteria

Epithelioid Sarcoma

Differential Diagnosis

Central necrosis of epithelioid sarcoma may simulate granulomatous disease, infectious or autoimmune
Palisaded Necrotic Granuloma Epithelioid Sarcoma
Keratin negative Keratin positive
CD34 negative CD34 50% positive
Indistinct cytoplasm Sharply defined eosinophilic cytoplasm
Rheumatoid nodules uncommon on hand and wrist Common on hand and wrist
Always think of epithelioid sarcoma when an extremity lesions looks granulomatous

 

Keratin positivity is typically seen in both
Squamous Carcinoma Epithelioid Sarcoma
CD34 negative CD34 50% positive
Uncommon in young people Most patients under 40 years
May have in situ lesion or keratinization No in situ lesion or keratinization
May have history of epithelial primary No primary epithelial lesion
CK5/6 commonly extensive CK5/6 rare, focal
CA125 negative in cutaneous SCC, frequently positive in SCC of other sites CA125 90% positive
CD34 reactivity is very rare in carcinoma of any type

 

Keratin positivity is typically seen in both
Sweat Gland Carcinoma Epithelioid Sarcoma
CD34 negative CD34 50% positive
May express GCDFP15, S100, actin GCDFP15, S100, actin negative
CD34 reactivity is very rare in carcinoma of any type

 

Both may present as keratin positive spindle cell neoplasms
Epithelioid Sarcoma Monophasic Synovial Sarcoma
Usually superficial Usually deep
Necrosis frequently extensive Necrosis usually focal
CD34 50% positive CD34 negative
No ropy collagen Ropy collagen frequent
Calcification infrequent Calcification frequent
No hemangiopericytomatous vessels Hemangiopericytomatous vessels frequent
No SYT-SSX gene fusion SYT-SST gene fusion present
TLE1 0% (0/2) TLE1 97%
CA125 90% positive CA125 negative

 

Abundant well defined cytoplasm in a dermal tumor may simulate melanoma
Melanoma Epithelioid Sarcoma
S100, HMB45 positive S100, HMB45 negative
Keratin very rare Keratin positive
CD34 negative CD34 50% positive
May have adjacent junctional component No junctional component
CA125 negative CA125 90% positive
INI1 positive INI1 loss in 91%

 

Epithelioid Hemangioendothelioma Epithelioid Sarcoma
CD31 usually positive CD31 negative
Keratin negative Keratin positive
Uncommon on distal extremities Common distally
Frequently small nested pattern Nodular or sheets
May be centered on a vessel Not centered on a vessel

 

Epithelioid Sarcoma Sclerosing Epithelioid Fibrosarcoma
EMA and keratin often strongly positive EMA and keratin negative or focal and weak
Often granuloma-like Cords of cells in hyalinized stroma
Eosinophilic cytoplasm Clear cytoplasm

 

Epithelioid Sarcoma Ischemic Fasciitis
Usually extremities of young patient Usually shoulder or hip of elderly patient
Usually brightly eosinophilic cytoplasm Cytoplasm usually basophilic or amphophilic
Keratin positive Keratin negative
Both are frequently CD34 positive

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