Ultrasound diagnosis of oesophagostomiasis

Human infection with Oesophagostomum bifurcum, a parasitic intestinal helmi nth, is endemic in parts of West Africa. Oesophagostomum bifurcum juveniles develop in the colonic wall, causing pus-filled granulomas. The pathology has two distinct forms. Multinodular oesophagostomiasis comprises hundreds of small nodules within a thickened, oedematous wall of the large intestine . Uninodular oesophagostomiasis, called the Dapaong tumour, presents as a p ainful 30-60 mm granulomatous mass in the abdominal wall or within the abdo minal cavity. Diagnosis of oesophagostomiasis on clinical grounds alone is difficult. We describe cases illustrating the ultrasound appearance of thes e two presentations. Multinodular disease shows nodular "target" and "pseud okidney" colonic lesions. The Dapaong tumour is an echo-free ovoid lumen en veloped within a well defined poorly reflective wall.