EPIDERMOID CYST OF THE SPLEEN WITH CA19-9 OR CARCINOEMBRYONIC ANTIGENPRODUCTIONS - REPORT OF 3 CASES

True splenic cyst is a relatively rare disease, and the majority of th e cases are classified as epidermoid cysts. Three cases of epidermoid cysts in the spleen or accessory spleen were studied using an immunohi stochemical technique and staining for mucin. In case 1, serum carcino embryonic antigen (CEA) and CA19-9, and in cases 2 and 3, serum CA19-9 , before surgery were markedly elevated. and these levels decreased po stoperatively. This strongly indicates the relationship between the in crease of tumor marker levels and the presence of the epidermoid cyst. In addition, stratified squamous epithelium in the resected tissues o f cases 1 and 2 was positive for anti-CEA antibody and anti-CA19-9 ant ibody, and that of case 3 was positive for anti-CA19-9 antibody. This strongly supports CEA or CA19-9 production in the squamous epithelium.