A case of duodenal strongyloidiasis presenting as a gastric outlet obstruction and endoscopically mimicking malignancy: a case report and mini review of literature

Abstract

Strongyloidiasis is a neglected soil-transmitted helminthiasis caused by Strongyloides stercoralis, affecting an estimated 300–600 million people worldwide. Due to its ability to cause autoinfection, the parasite may persist lifelong and lead to severe complications. While gastrointestinal symptoms are common, presentation as gastric outlet obstruction (GOO) is rare and can mimic malignancy. A 42-year-old male presented with several months of non-projectile vomiting, epigastric pain, indigestion, anorexia, and significant weight loss. Examination revealed dehydration, hypotension, and tachycardia. Laboratory tests showed mild microcytic anemia and mild hyponatremia, with normal eosinophil counts. Abdominal ultrasonography suggested gastric outlet obstruction. Upper gastrointestinal endoscopy demonstrated a circumferential ulcerated duodenal lesion with pyloric deformity, initially suspicious for malignancy. Histopathological examination of duodenal biopsies revealed S. stercoralis. After correction of hypovolemia and electrolyte imbalance, the patient was treated with ivermectin, resulting in complete resolution of symptoms. Strongyloidiasis has a broad clinical spectrum, ranging from asymptomatic infection to disseminated disease. Gastric outlet obstruction is an uncommon manifestation and poses diagnostic challenges, particularly in endemic regions. Endoscopy with histopathological confirmation is essential for diagnosis when clinical and laboratory findings are non-specific. Prompt treatment with ivermectin is highly effective and prevents serious complications. Strongyloidiasis should be considered in the differential diagnosis of gastric outlet obstruction, especially in endemic areas. Early diagnosis and timely antiparasitic treatment are crucial to reduce morbidity and prevent life-threatening complications. • Strongyloidiasis can rarely present as gastric outlet obstruction, closely mimicking upper gastrointestinal malignancy. • Endoscopic biopsy with histopathological examination is critical for diagnosis when clinical, laboratory, and imaging findings are non-specific. • Normal eosinophil counts do not exclude strongyloidiasis, underscoring the need for a high index of suspicion in endemic regions. • Timely treatment with ivermectin leads to complete clinical resolution and prevents severe or life-threatening complications.