Malignant vascular neoplasms such as epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS) can arise within the liver. The aim of this study was to study the expression of keratins CK7, AE1/AE3 and OSCAR in primary hepatic EHE and AS. 9 cases of hepatic EHE and 13 cases of hepatic AS were stained with ERG, CK7, keratin AE1/AE3 and keratin OSCAR. Their expression was graded as 1+ (1-25% of tumor cells positive), 2+ (26-50%), 3+ (51-75%) or 4+ (>75%). ERG was positive in all 9 (100%) EHEs and all 13 (100%) ASs. CK7 was positive in 5/9 (56%) EHEs (2, 1+; 1, 2+; 1, 3+; 1, 4+) and 1/13 (8%) AS (2+). Keratin OSCAR was positive in 6/9 (67%) EHEs (5, 1+; 1, 2+) and 4/13 (31%) ASs (2, 1+; 1, 2+; 1, 4+). Keratin AE1/AE3 was positive in 6/9 (67%) EHEs (3, 1+; 3; 2+) and 4/13 (31%) ASs (2, 1+; 1, 2+; 1, 4+). Overall, 6/ 9 (67%) EHEs were positive for at least one keratin marker, of which 5 were positive for all 3 keratins (AE1/AE3, OSCAR and CK7) while 1 was positive only for 2 keratins (OSCAR and AE1/AE3). 4/13 (31%) of ASs were positive for both keratins OSCAR and AE1/AE3, of which 1 case was also positive for CK7. Aberrant keratin expression is common in primary hepatic EHEs (67%) and ASs (31%). Awareness of this diagnostic pitfall is important for avoiding misdiagnosis of these primary hepatic malignant vascular tumors as carcinomas.
Keywords: Angiosarcoma; Epithelioid hemangioendothelioma; Keratin; Liver; Vascular.
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