Summary
Background: Gastroschisis is a defect of abdominal wall in which intestinal loops are displaced outside the abdominal cavity through a defect in the abdominal wall situated usually right to the umbilical cord, not covered by a pouch. Mesenchymal hamartoma of the liver is a rare benign, tumourlike malformation in children. In the literature on the subject the authors did not find a case of concomitant gastroschisis and mesenchymal hamartoma of the liver.
Case Report: The newborn in the first day of life was operated on for congenital abdominal wall defect–gastroschisis. Apart from eviscerated intestinal loops in the upper part of the operative wound,it was found a pedunculated solid mass penetrating towards the liver hilus, left to the gall bladder. Microscopic evaluation of the excised tumour revealed hepatocytes in chaotic distribution, forming
more or less regular trabeculae, numerous blood and lymphatic vessels of various diameter and small biliary ducts embedded in the connective tissue, but there were no cystic structures typical for hamartoma. Due to the lack of cystic structures, microscopic picture of described case differs from a typical picture of hamartoma mesenchymale of the liver. However, the other elements present in the tumour were described in various proportions in all cases of hamartoma.
Conclusion: We desribed the first case of the coexistence of gastroschisis and hamartoma mesenchymale-like tumor of liver in one day newborn. The coexistence of gastroschisis and hamartoma mesenchymalelike tumor probably was accidental. The atypical microscopic picture in described case may result from very young age of our patient.

Keywords: Gastroschisis, Hamartoma, Liver, congenital wall defects, hepatic tumors