Two cases of the same family with the unusual elevation of CA19-9 levels.

Introduction: Serum carbohydrate associated antigen (CA19-9) is widely used marker in clinical practice and shows small increases in a few benign diseases. Here we report two cases, a mother and her daughter with slightly elevated CA19-9 levels not accompanied by any clinical pathology.

Case Presentation: The mother with elevated CA19-9 level (89.90 U/mL; upper limit of normal range (ULNR) < 37 U/mL) was referred to our department for evaluation. Similar increase was determined in her daughter incidentally. Daughter's CA19-9 level was 123.92 U/mL. Extensive laboratory data, imaging procedures and clinical evaluations were within the normal ranges except elevated CA19- 9 levels for both. Also, any pathology compatible with the elevated CA19-9 level couldn't be determined. In order to avoid laboratory errors and interferences, we measured the samples at four different immunoassay platforms twice.

Conclusion: Healthy people can be in excess of the ULNR. Therefore, clinicians need to be aware of these rare situations without missing the malignant disorders.