[Significance of CA19-9 in mature cystic teratoma]

We comparatively studied preoperative and postoperative serum CA19-9 levels in 170 mature cystic teratoma (MCT) cases. In MCT cases with positive serum CA19-9 levels, immunohistochemistry by means of an enzyme immunoassay was performed to determine in which tissues the high levels of serum CA19-9 had originated. 1. The preoperative serum CA19-9 level was high, 83.8 U/ml, against the low postoperative level of 32.9 U/ml. This suggested the possibility of CA19-9 being produced in the tumor of MCT. 2. There were 31 CA19-9 positive cases and CA19-9 was found in the bronchial gland tissue and surface epithelium in 9 and 4 cases, respectively, out of 23 cases with serum levels of more than 101U/ml. Out of 45 cases with normal CA19-9 levels, 4 had bronchial gland tissue and 3 had surface epithelium, both without CA19-9. Lewis system examination of those cases indicated Lewisa(-) and Lewisb(-) in all of them. 3. CA19-9 levels were higher in cystic fluid than in serum from MCT patients. This suggested two routes for the transfer into blood of tumor-tissue-produced CA19-9: 1) directly excreted in serum via surface epithelium; 2) retained in the ovarian cyst, then leaking into surrounding capillary vessels via the interstitium. 4. Clinically, CA19-9 is a marker necessary for examining MCT recurrence.