[Pediatric vascular tumors of liver:a clinicopathological study of 22 cases].

Objective: To investigate the clinicopathological features of hepatic vascular tumors in children. Methods The clinical characteristics, histology and immunohistochemical staining results were summarized and analyzed in 22 cases of hepatic vascular tumors in children at Guangzhou Women and Children's Medical Center from September 2007 to November 2020. Results: The 22 patients aged from 1.0 month to 2.5 years (mean age 9 months). There were 10 males and 12 females. Five cases were found in premature and had low birth weight infants; three cases were discovered in the antenatal period; one patient also had cutanous hemangioma; six patients had associated anemia; Kasabach-Merritt phenomenon was not seen in any patient. CT examination showed 17 tumors were solitary and five were multifocal lesions. Macroscopically, the tumors size ranged from was 0.6 cm to 11.0 cm; the cut surface was solid, gray red and brown in color, and in six cases there were hemorrhage and necrosis in the central area. Microscopically,15 cases of solitary congenital hepatic hemangiomas showed characteristic necrosis in the central area, with loose fibrous tissues at periphery. Proliferation of capillaries, residual bile ducts between the vascular lumens, and dilated thrombosed vascular channels were seen, and contained extramedullary hematopoietic foci and calcification. Five cases of multiple hepatic infantile hemangiomas showed capillaries of different sizes composing of plump endothelium and pericytes and were arranged in lobular or diffuse patterns. Two cases of cavernous hemangioma (venous malformation) consisted of dilated thin-walled blood vessels with branch-like pattern lined with flat endothelial cells. Immunohistochemically, all 22 case expressed vascular endothelial markers CD31 and CD34, but D2-40 was negative. Glut1 was positive in five cases of multiple hepatic infantile hemangiomas, and the other cases were negative. Conclusion: Hepatic vascular tumors in children are rare, and their classification is different from that of adults. It is of great significance to make clear pathologic diagnosis.