Abstract
Introduction: Giardial infection of humans commonly presents as abdominal pain and diarrhea. There have been, however, only few case reports where Giardia organisms were incidentally retrieved from pancreatic masses that were found on imaging studies. Case presentation: 71-year-old male was referred to our tertiary center with intermittent vague and worsening abdominal pain, associated with weight loss of 15lbs since he was first diagnosed with acute pancreatitis 7 months ago. Patient was being treated with pantoprazole after esophagogastroduodenoscopy showed erosive gastritis. His medical history is significant for atherosclerotic vascular disease and hypertension. Surgical and family history were non-contributory. He was a heavy smoker with daily moderate alcohol consumption. Physical exam was unremarkable. His complete blood count, basic metabolic panel and liver chemistries were unrevealing. Lipase was 125 IU/L (normal 0-59). CA19-9 was 67 U/ml (normal 0-35). Because MRI of abdomen showed a complex cystic lesion in the inferior aspect of the pancreatic head, we proceeded with endoscopic ultrasound. This showed scattered hyperechoic foci and hyperechoic strands with no lobulization. There was an ill-defined hypoechoic and heterogenous mass 29.6x19.3mm (figure 1). Fine needle aspiration of the pancreatic mass and a paraduodenal lymph node was performed.Cytopathology results showed no evidence of malignancy. However, parasitic organisms morphologically consistent with Giardia were found in the aspirate from the pancreas and the lymph node (figure 2). Stool for ova and parasites failed to show any organisms. Patient was treated with metronidazole for 7 days. Repeat EUS after 2 months showed shrinkage of the mass. The patient on follow up reported resolution of symptoms. Discussion: This surprising finding of Giardia as a cause of inflammatory pancreatic masses stresses the importance of investigating the possibility of giardial infection even in the setting of nonrevealing stool test, especially in endemic areas. Repeating the endoscopic ultrasound was necessary to rule out pancreatic malignancy, especially the coexistence of cancer and giardial infection should be excluded. Some investigators reported resolution of pancreatic cysts after appropriate treatment for the parasite. It is worthy to mention that giardiasis was found to be associated with chronic pancreatitis. Further studies are needed to elucidate whether Giardia plays a role in pancreatic cancer.