Myxedema ascites with an extremely elevated CA125 Level: a case report.

Carbohydrate antigen 125 (CA125) is a tumor-marker frequently associated with ovarian malignancies; however, benign gynecologic conditions (e.g. ovarian cysts) commonly cause a smaller increase in CA125 levels. This report describes an elderly Japanese woman with high CA125 levels and massive ascites caused by hypothyroidism. A 67-year-old woman presented herself with a weight gain of about 12 kg and abdominal distension. Her serum CA125 level was markedly elevated (822 U/ml) and abdominal CT revealed a right ovarian cyst and massive ascites. Hormonal laboratory data showed severe primary hypothyroidism with a serum TSH of 594 IU/L and a free thyroxin level of 0.05 ng/dl. Ascitic fluid was found to be exudate with a high protein content of 42 g/L. Cytological analysis and FDG-PET showed no evidence of malignancy. The ascites completely disappeared and serum CA125 normalized after adequate hormonal replacement therapy. These data suggest that hypothyroidism should be considered in patients with ascites and elevated serum CA125.