Primary malignant vascular tumors of the liver in children: Angiosarcoma and epithelioid hemangioendothelioma

Table 1 Clinicopathologic characteristics of pediatric hepatic angiosarcoma and epithelioid hemangioendothelioma

	Angiosarcoma	Epithelioid hemangioendothelioma
Demographics	Female predominance; mean age at diagnosis: 40 mo	Female predominance; median age at diagnosis: 12 yr
Clinical presentation	Abdominal pain, and distension due to rapid liver enlargement. Lung metastasis is common	Mostly present with multiorgan involvement, most frequently involving liver, lungs, bone and soft tissue
Associated conditions	Cutaneous and hepatic infantile hemangiomas, cutaneous vascular malformations, dyskeratosis congenita	None reported
Molecular	Unknown (ROS1-GOPC fusion reported in an adult hepatic angiosarcoma)[29]	WWTR1-CAMTA1 fusion (90%) YAP1-TFE3 fusion (10%)
Histology	Well-formed, anastomosing vessels to more solid areas composed of pleomorphic spindle cells. Hypercellular whorls of spindled cells (glomeruloid bodies). Intracytoplasmic eosinophilic globules (periodic acid-Schiff -positive and diastase-resistant)	Cords and nests of epithelioid cells in a variable fibromyxoid stroma. Occasional intracytoplasmic vacuoles/lumina. Minimal cytologic atypia with low mitotic rates
Immunohistochemistry	CD31, CD34, factor VIII, FLI-1, ERG, occasionally podoplanin and GLUT-1	CD31, CD34, factor VIII, FLI-1, ERG, variable podoplanin, smooth muscle actin and keratin