A splenic cyst and a high serum CA 19-9: a case report.

A 22-year-old man was admitted to our hospital with a palpable mass in the left upper quadrant. He had a history of blunt abdominal trauma. Computer tomography showed a large splenic cyst. Another finding was a markedly elevated concentration of the tumor marker CA 19-9 in his serum and cystic fluid. After surgical removal of the cyst this concentration decreased to a nearly normal level. Because no cellular lining of the cyst was found at histological examination, the cyst could have been regarded as 'false' or a 'pseudocyst'. However, since several cases of epithelial splenic cysts in combination with a high serum CA 19-9 have been described recently, our diagnosis was of an epithelial 'true' cyst. We assume that, for some reason, in primary splenic cysts, the thin cellular lining can be released before histological examination is performed.