Mummificated form of hookworm as a cause of bleeding duodenal bulb lesion – case report

An 81 year-old man taking 100mg aspirin daily was admitted because of and rapidly worsening dyspnoea and severe anaemia. Laboratory data showed typical iron-deficiency anaemia (haemoglobin 5.0g/dl, hematocrit 20.5%, serum iron 18µg/dl). Eosinophilia was not detected and the FOBT was positive.

After transfusion with 5 unites of packed red blood cells upper endoscopy was performed. On the anterior wall of the duodenal bulb an 8–10mm in length speculum like foreign body was found. The spike was bedding in a sessile polyp like mucosal protuberation with an ulcerated inner margin.

The whole pathologic body was removed by a polypectomy snare using mucosectomy technique. Histopathologically the speculum like body was found to be a female hookworm (Ancylostoma duodenale) containing large amount of eggs. The original tissue formation of the worm was not detectable and the surrounding inflammed and ulcerated mucosa was also deeply infiltrated by hookworm particles.

Endoscopy on the 7^th day showed a non bleeding post polypectomy ulcer in the duodenum and no hookworm eggs were detected in the patient's stool. Oral iron and PPI therapy was given and despite of continued aspirin medication anaemia resolved rapidly without further blood transfusion. Control endoscopy at month four showed normal gastroduodenal mucosa.

Hookworms usually live in the upper part of the small intestine, with relatively few in the duodenum. The classic clinical symptom in an active hookworm disease is iron-deficiency anaemia. In our case we suggest that as a late result of previous hookworm infection the lifeless and mummificated remnant of the Ancylostoma duodenale may cause chronic mucosal injury with reactive inflammation and mucosal ulceration. Our patient, a former forest-officer, presumably suffered his hookworm infection in his earlier lifetime being asymptomatic until introducing aspirin medication. Aspirin provoked chronic occult bleeding resulting severe anaemia and clinical symptoms. After endoscopic removal of the unusual structure resolved the problem and total mucosal healing was achieved.