Strongyloidiasis: An Incidental Discovery on Colonoscopy in an Asymptomatic Immunocompromised Host

Abstract

Strongyloidiasis can range from asymptomatic eosinophilia in an immunocompetent host to disseminated disease with septic shock in an immunocompromised host. In this case, we present the incidental finding on routine colonoscopy of strongyloidiasis in an immunocompromised host. A seventy-one year-old gentleman with past medical history notable for Chronic Lymphocytic Leukemia on therapy with imatinib presented for an esophagogastroduodenoscopy (EGD) and colonoscopy for evaluation of intermittent solid food dysphagia, weight loss, and normocytic anemia. He denied any odynophagia, abdominal pain, diarrhea, constipation, hematochezia, or melena. Physical examination was normal and cursory review of the laboratory data revealed only a mild normocytic anemia. EGD was normal. Colonoscopy revealed severe pandiverticulosis and in the ascending colon, a small (< 1cm) raised sessile lesion was encountered with an odd appearance to it. It did not have the classic pattern of either a tubular or sessile serrated adenoma when examined under white light (Image 1) or narrow band imaging (Image 2). The lesion did not evert when poked by the biopsy forceps, making an inverted diverticulum unlikely. Snare cautery polypectomy was performed and later to our surprise, the pathology returned back as it being an eosinophilic abscess with numerous strongyloides organisms present (Image 3) Upon further review of the patient's chart, it was noted that he had peripheral eosinophilia for years but this had gone largely unnoticed. The patient received anti-helminthic therapy with ivermectin and did well with complete resolution of his peripheral eosinophilia over time. The most common manifestations of strongyloidiasis are mild waxing and waning gastrointestinal (i.e. diarrhea), cutaneous (i.e. rash, pruritus), or pulmonary symptoms (i.e. cough, dyspnea) that can persist for years. More often than not, patients are asymptomatic and the presence of peripheral eosinophilia is the only marker to suggest a parasitic infection. In addition, as in our case, there are no classic endoscopic features of strongyloidiasis and it can mimic that of other diseases. Overall the prognosis of strongyloidiasis is good if detected early and treated appropriately. It is especially important to be worried about infection in immunocompromised individuals given they are at risk for developing a potentially fatal hyperinfection syndrome that can result in multi-organ failure and death.Figure: Image 1- White Light View of Lesion.Figure: Image 1- Narrow Band Imaging View of Lesion.Figure: Image 3- Strongyloides filariform larvae seen in upper left portion of slide with surrounding eosinophilia.