Tuberculous peritonitis with extraordinarily high serum CA125.

A 74-year-old woman who was admitted for the evaluation of ascites showed a marked elevation of serum CA125 level. Laparoscopy revealed the presence of numerous white modules (approximately 5 mm diameter) on the peritoneum suggestive of tuberculomas. A biopsy specimen showed epithelioid cells and Langhans-type giant cells. Following the administration of diuretics, the level of serum CA125 decreased concomitantly with the decrease in the volume of peritoneal fluid. The level of CA125 decreased further with the administration of antituberculosis agents. Clinical specimens were negative for mycobacteria. We conclude that the elevated serum level of CA125 was due to peritoneal tuberculosis and consequent ascites. Thus, tuberculous peritonitis should be considered in the presence of an unexplained, abnormally elevated serum level of CA125.