1346 CA 19-9: Elevation in Mycobacterium Avium-Intracellulare Infections

Abstract

INTRODUCTION: Carbohydrate antigen 19-9 is usually associated with pancreatic malignancy. However, other causes as bronchiectasis can cause lab elevation. Here we present a case of an elevated CA 19-9 with pulmonary mycobacterium avium-intracellulare. CASE DESCRIPTION/METHODS: 66 year old HIV negative female with MAI (Figure 1) on Ethambutol, Rifampin, Azithromycin (started 4/2017, stopped 10/2017, restarted 1/2018) presented to clinic with complaints of epigastric pain with unintentional weight loss. She was started on proton pump inhibitor and H2 blocker therapy and underwent EGD and colonoscopy with biopsies positive for Helicobacter pylori. She received quadruple therapy with eradication on stool antigen. She complained of a mass in her supra-pubic region and given this with her weight loss and normal endoscopies, a CT Abdomen and Pelvis was performed which showed no hepato-biliary abnormalities but significant bladder distention (Figure 2). This resolved on its own prior to her seeing urology or coming in for follow up. A CA 19-9 remained elevated at 105, 94, and 111 during this time frame. DISCUSSION: Mycobacterium is a masquerader causing hydronephrosis to bronchiectasis, both seen in our patient, with the mechanism of CA 19-9 elevation unknown. Shin et al presented a patient with MAI and elevated CA 19-9 levels, which improved with treatment. 1 Studies have shown an elevated CA 19-9 may be from MAI infection or other causes of bronchiectasis, such as Chang et al in 2013. 2 Yamazaki et al compared CA 19-9 in patients with deteriorated (96.9) vs non-deteriorated (19.2) disease. 3 Hong and colleagues in their analysis showed that CA 19-9 could be elevated in patients with MAI and improved with treatment. 4 Here, we highlight the importance of a differential diagnosis of non-pancreatic etiologies for elevated CA 19-9 levels.