Introduction

Ascariasis is a common helminthic disease of the human gastrointestinal tract caused by the parasitic worm Ascaris lumbricoides (AL) that primarily affects developing tropical countries. Adult AL usually inhabit the intestinal lumen without causing any significant symptoms or health problems. Occasionally, adult worms can migrate to the biliary tract through the ampulla of Vater, causing symptoms similar to those of choledocholithiasis, or to the pancreatic duct, causing symptoms similar to the ones observed in pancreatitis cases.

Clinical case

A 47-year-old male from Leticia (Amazonas, Colombia) was referred due to experiencing severe (burning sensation) abdominal pain (8/10) in epigastrium and right hypocondrium, spasms, multiple emetic episodes of biliary characteristics and the presence of choluria for 2 weeks.

As a result, the patient was referred to a secondary care center, where he was diagnosed with hyperamylasemia (595 mg/dL) associated with hyperbilirubinemia (Table 1). Furthermore, positive acute phase reactants and imaging findings, using an enhanced computed tomography (CT) scan, were compatible with acute pancreatitis (Balthazar grade D) (Figure 1), which was classified as moderate to severe according to the clinical severity index, with an APACHE II (Acute Physiology and Chronic Health Evaluation II) score of 7. Consequently, management was initiated with fluid resuscitation, antibiotic treatment with ampicillin/sulbactam, and cessation of feeding.

Table 1 Patient’s lab tests results on admission and at discharge 

LAB: lab test; LEU: leukocytes; NTRO: neutrophils; Hb: hemoglobin; AP: alkaline phosphatase; TB: total bilirubin; BD: direct bilirubin; GOT: glutamic oxaloacetic transaminase; GPT: glutamic pyruvic transaminase; CRP: C-reactive protein; IU: international unit.

Figure 1 Abdominal CT scan: hepatomegaly and fat infiltration, pancreatitis (Balthazar D) with severity index score of 5, bilateral pleural effusion, and small amount of free fluid in the abdominal cavity. Source: Own elaboration. 

An abdominal ultrasound was performed as a complementary study, revealing a gallbladder polyp and biliary sludge without alterations of the bile duct. Endoscopic ultrasonography was performed due to the intermediate risk of choledocholithiasis associated with an increase in bilirubin levels, alteration of the liver panel, clinical symptoms of biliary pancreatitis (Table 1), and greater sensitivity for microlithiasis. Imaging manifestations of cholelithiasis were observed, which were consistent with AL in the choledochal lumen, with an elongated hyperechogenic tubular structure that did not produce acoustic shadowing and railway track sign (Figure 2). Albendazole treatment was prescribed (400 mg orally, every 24 h for 3 days) and an ERCP was performed, along with papillotomy and removal of ascaris from the biliary tract. There were no postoperative complications (Figure 3).

Figure 2 Pancreatobiliary endoscopic ultrasonography: cholelithiasis, biliary ascariasis. CBD: Common bile duct. Source: Own elaboration. 

Figure 3 ERCP: biliary route slightly dilated from 7 to 8 mm, with delayed filling defect and railway track sign due to the presence of ascaris. Source: Own elaboration. 

During his hospitalization, the patient’s condition improved, and complete remission of acute pancreatitis was achieved. Afterwards, he was referred to undergo laparoscopic cholecystectomy due to the cholelithiasis diagnosis made through endoscopic ultrasonography, and no complications were reported.

Discussion

Obstructive jaundice has several causes of both malignant and benign origin. One of them, which is also rare and difficult to diagnose, is obstruction of the common bile duct (CBD) due to AL infection, a nematode that parasitizes humans and can be between 10 and 30 cm in length¹.

In general, about 30% of patients with AL in the CBD have undergone cholecystectomy. It has been concluded that this causes a dilatation of the CBD, which is associated with an increase in cholecystokinin production, resulting in the relaxation of the sphincter of Oddi and, this way, facilitating the migration of the parasite to the CBC².

Conclusions

Biliopancreatic endoscopic ultrasonography is a useful diagnostic tool, with high sensitivity and specificity rates to detect CBC diseases. Interventions associated with morbidity must be avoided in cases of suspected biliary obstruction of unknown etiology, while biliopancreatic endoscopic ultrasonography is the diagnostic tool of preference if there are symptoms of BA.

Since combined use of ERCP and anthelmintics is an efficient therapy, it is considered the first-line treatment of BA