Clinical History
Patient diagnosed of acute gallstone pancreatitis 3 months before. She had required multiple admissions to a hospital due to successive episodes of clinical worsening with development of liquefied gland necrosis. The patient was transferred to our institution because of a new episode of worsening.
Imaging Findings
Transverse abdominal CT obtained with intravenous and oral contrast material (Fig. 1) reveals fluid collections associated with liquefied necrosis and gallstones. In other slice you can see a tubular filling defect within the jejunal lumen, about 30 cm long and 0.4 cm thick.
Barium enema examination of the intestine (Fig. 2) confirmed the translucent filling defect in the lumen.
Discussion
The roundworm Ascaris lumbricoides usually inhabits the small intestine. It is the most common parasitic infection worldwide [1], although it predominates in areas of poor sanitation and in the developing world [2].
Humans become infected after ingesting material contaminated with eggs. Gastric secretions cause the eggs to hatch in the small bowel. The larvae penetrate the intestinal mucosa and are haematogenously transported to the lung. The worms grow and travel up the airway to be swallowed again, so they will be back in the small bowel [2].
Worms can often be seen on abdominal radiographs as curvilinear soft-tissue-density cords. At US, they appear as an echogenic tubular structures without distal acoustic shadowing, with a central hypoechoic area (the worm's digestive tract). Live worms may occasionally be observed moving. Contrast studies (fluoroscopy, CT or MR) can reveal a tubular filling defect within the lumen [1, 3]. Adult worms are 15–50 cm in length and 3–6 mm thick [4]. With these features, the diagnosis is fairly straightforward.
While the vast majority of these cases are asymptomatic, infected persons may present vague symptoms such as nausea, vomiting, anorexia, abdominal discomfort, or colicky pain. The worms can even cause pneumonia, intestinal obstruction, pancreatitis, volvulus, intussusception, pancreatitis, cholecystitis or and liver abscess [4].
Many of the conditions can often be managed with conservative anthelminthic therapy. Occasionally, endoscopic or surgical intervention is required [1, 5].
In our case, we hypothesise that some of the patent's digestive symptoms were due to the ascaris, but they were misdiagnosed because of the pancreatitis. Albendazole treatment made the patient better right away. Although there are many cases reporting pancreatitis due to ascariasis [1, 5], we reviewed the prior studies of the patient, and we found the worm in the jejunum since the onset of the pancreatitis, without evidence of parasitic obstruction of papilla of Vater, invasion of common bile duct, or pancreatic duct.
Teaching Point:
Abdominal pain or discomfort is a common cause of imaging referral. Ascaris can cause some of these symptoms. We must pay special attention to the bowel lumen of patients with unexplained symptoms to not overlook the findings.
Differential Diagnosis List
Ascariasis clinically hidden because of pancreatitis
Tapeworms
Enteral tubes
Final Diagnosis
Ascariasis clinically hidden because of pancreatitis
