An extremely elevated serum CA125 level in a Crohn's patient developing endometriosis and the establishment of a cell line (MD-E) from the endometrioma.

We report an extremely high serum CA125 value of 1243 units/mL in a 21-year-old-patient with Crohn's disease who developed endometriosis. Such a high CA125 value has not been reported to date in endometriosis or other pathologies except ovarian carcinoma. The pelvic mass of unknown nature in the above patient was discovered by ultrasound during a sudden onset of severe abdominal pain which subsided within two days. The high CA125 value six days after the onset of pain and at the end of menses declined spontaneously to 100 units/mL in 15 to 30 days, and stabilized over the three months prior to colectomy and removal of the left ovarian endometrioma, after which it gradually declined to 7 to 11 units/mL as found a year earlier. Although primary cells from endometrioma produced 113 units/mL of CA125 in the culture medium, the cell line established from it gave a value of less than 7 units/mL even after treatment with interferons. The adherent cells were moderately positive for CA125, cytokeratin and non-specific esterase, were strongly positive for periodic acid Schiff's (PAS) and acid phosphatase, and had epithelioid morphology. In addition to the extremely high CA125 level in our endometriosis patient and the establishment of the cell line, the case illustrates the usefulness of CA125 estimation in helping to determine the nature of abdominal masses in female inflammatory bowel disease patients.