Congenital fibrosarcoma of the jejunum in a premature infant with meconium peritonitis.

We report an unusual case of perforation of a congenital fibrosarcoma of the jejunum in utero and secondary meconium peritonitis. Prenatal ultrasound showed polyhydramnios and fetal ascites from 25 gestational weeks in the absence of other fetal congenital anomalies. A 2200 g baby girl was born at 34 weeks gestation, presenting with severe generalized edema and respiratory distress immediately after birth. Plain radiography revealed progressive abdominal distension and pneumoperitoneum. The baby subsequently underwent surgery at the age of one day. A perforation of the upper jejunum, which had resulted in meconium peritonitis, was discovered intraoperatively and the perforated section of the intestine was resected and anastomosed successfully. The postoperative course was uneventful. Pathological examination confirmed that the perforation was caused by rupture of a congenital fibrosarcoma originating from the jejunum. Rupture of a malignant tumor is an extremely rare cause of peritonitis in the fetus and neonate.