Introduction: CA 19.9 is considered the most specific and sensitive serological marker of pancreatic adenocarcinoma. However, serum CA 19.9 can be raised in several non-neoplastic disorders, particularly in various benign pulmonary diseases. An increase in serum CA 19.9 in bronchiectasis remains exceptional.
Case report: We report the case of a 67 year old woman in whom a serum level of more than 1500 U/ml (normal value less than 37 U/ml) was found incidentally. Exhaustive investigation and clinical evolution excluded a neoplastic digestive disorder but positron emission tomography revealed a distinct hypermetabolic focus in the area of the hilum of the right lung. A complementary work-up (CT scan and fibreoptic bronchoscopy) demonstrated bilateral bronchiectasis colonised with Haemophilus influenzae. Antibiotic therapy with amoxicillin-clavulanic acid brought about a decrease in the serum CA 19.9 but level of the tumour marker remained abnormal after more than 2 years.
Conclusion: This case report emphasises the uselessness of tumour markers as screening tests as a serum level of CA 19.9 up to 50 times normal may be found in benign respiratory disorders such as bronchiectasis.