Transient increase of CA 19-9 serum concentrations in a liver transplant recipient with cystic fibrosis and hepatic abscess: a case report and brief literature review.

CA 19-9 (carbohydrate antigen 19-9) is a tumor marker widely used for surveillance of patients with pancreatic cancer. However, even high levels of CA 19-9 may not necessarily be cancer-associated thereby complicating the diagnosis. This case report highlights a transient increase of CA 19-9 in a triple transplanted patient with cystic fibrosis and continuous immunosuppression for 20 years who was under antibiotics. This case emphasizes the need for a balanced interpretation of biological results, especially in cases where many confounding factors are present such as diabetes, chronic renal failure, cystic fibrosis and infections. This case also provides an opportunity to formulate a number of recommendations for the interpretation of tumor marker results in order to avoid long and costly further investigations.