Abstract
A 15-year-old male was diagnosed as having a splenic cyst in December, 2004. He presented to the hospital because of severe abdominal pain after suffering a bruise in September 2008. The serum CA19-9 level was high at 1044U/ml. Computed tomography revealed a collapsed splenic cyst surrounded by ascites. Peritonitis due to splenic cyst rupture was suspected, and a dome resection with coagulation was thus performed via a laparotomy. The CA19-9 level in the cystic fluid was high at 4.19×106U/ml, but there was no cytological evidence of malignancy. The histological diagnosis was benign true cyst. Immunostaining showed positive responses for CA19-9 in the intra-cystic epithelium. After surgery, the serum CA19-9 level returned to the normal range. The patient has since been free of recurrence but is being followed closely, since there are few long-term follow-up studies on such cysts.
