Abstract

Liver tumors are rare in children. Hepatoblastoma (HB) is usually diagnosed during the first three years of life and represents approximately 80% of malignant tumors. Occasionally it  can  be  diagnosed  in  neonates  or  during  the  prenatal  period.  It  is  an  embryonic  tumor  that  originates  from  hepatocyte  precursors  that  recapitulate  stages  of  organ  development.  The  variant  of  undifferentiated  small  cells  or  Small  Cell  Undifferentiated  (SCUD),  is  an  epithelial variant of HB that represents between 3 to 5% of cases, occurring in a younger age  group  of  0-1  years  old  are  low  or  normal  serum  alpha-fetoprotein  unlike  the  classic  variant and exhibits a very aggressive clinical behavior. It is a population of small round and  blue  cells  that  co-express  stromal  and  epithelial  markers  and  can  grow  in  a  diffuse  pattern, in groups, nests or organoid pattern. Histology is a prognostic factor of death risk factor. There is a subgroup of SCUD that exhibits morphological and immunophenotypic characteristic of hepatic malignant rhabdoid tumors such as loss of nuclear expression of INI-1 by immunohistochemistry with or without deletion of the INI gene. It is an extremely aggressive neoplasm with a diffuse growth pattern and should be distinguished from other small and round small blue cell tumors. The objective is to present an infrequent case of embryonic hepatocyte tumor with prenatal presentation.

Keywords

hepatoblastoma, small cell, rhabdoid tumor, liver, prenatal, undifferentiated elements