Persistent elevation of serum CA 19-9 with no evidence of malignant disease

Abstract Background Serum CA 19-9 is the mainstay marker for the diagnosis of biliopancreatic malignancies, though a persistent elevation can also be observed in various benign diseases. Aims In this study, a marked increase of serum CA 19-9 was seen in 10 patients who had no evidence of malignant disease. The possible causes of this finding are discussed. Patients Nine women and one man were studied, whose admitting diagnoses were as follows: pulmonary fibrosis in two, diabetes in two, non-ulcer dyspepsia in two, obesity in one, acute diarrhoea in one, colon diverticula in one and gastric ulcer in one. Methods Routine blood tests, tumour marker determinations, imaging studies and endoscopy were carried out at admission. Results Serum CA 19-9 levels ranged from 112 to 1338 IU/ml (mean 517 IU/ml). Abdominal ultrasonography, CT-scan, upper gastrointestinal X-ray series and gastrointestinal endoscopies were negative for malignancy. During the follow-up period (range 2–7 years) serum CA 19-9 values were persistently elevated in all patients. Conclusions Our study shows that persistent and significant elevation of serum CA 19-9 can be found in non-malignant and non-cholestatic disease.