Chronic GI bleeding in a middle-aged woman

A middle-aged woman without any underlying systemic disease was referred to our hospital due to a 1-month history of recurrent black diarrhoea and anaemia. At presentation, her vital signs were stable and the physical examination was unremarkable except for pale conjunctiva. Laboratory tests showed iron-deficiency anaemia with a haemoglobin concentration of 7.3 g/dL (reference range, 11.1-15.1 g/dL). As she had no severe symptoms of anaemia, we administered oral iron preparations without blood transfusion and her anaemia was gradually corrected. Oesophagogastroduodenoscopy, colonoscopy and contrast-enhanced abdominal CT revealed no cause of bleeding, so obscure GI bleeding was suspected. Capsule enteroscopy revealed black fluid in the proximal small intestine, and subsequent peroral double-balloon enteroscopy detected a 1 cm diameter hemispheric elevated lesion at the upper jejunum (figure 1A, B). The lesion was non-pulsatile and hard in consistency, appearing as a submucosal tumour (SMT). An ulcer was located at the top of the lesion, suggesting the source of bleeding, although no blood clot was present around the site.gutjnl;68/8/1385/F1F1F1Figure 1Endoscopic findings of the jejunum on white light endoscopy (A) and chromoendoscopy with indigo carmine dye (B).

What is your diagnosis? Do you try to obtain biopsy specimens from this lesion?