Meckel’s Scan: Pitfall in Patients With Active Small Bowel Bleeding

Abstract

Potential for a false-positive Meckel's scan is highlighted in this patient with intermittent, low-volume small bowel bleeding. Meckel's scan showed late appearance of focal activity mimicking a positive diverticulum finding. This was secondary to extravasated tracer during a coincidental bleeding as shown by a Tc-99m tagged red blood cell scan obtained 2 days earlier. Inaccurate diagnosis of Meckel diverticulum was avoided by: 1) noticing the late appearance in relationship to the gastric uptake, and 2) showing motility of the focus on delayed dynamic imaging that confirmed transit of extravasated tracer along the small bowel with peristalsis. Subsequent capsule endoscopy showed a bleeding ulcer in the ileum.

Meckel’s diverticulum: misdiagnosis and late presentation

“…78 Similarly, Reddin and Rosenbaum 42 discovered a false positive scan for MD in a 32-year-old patient presenting with rectal bleedinga carcinoid tumor was found without MD. In a similar case, Tulchinsky 43 reported a patient with low-volume, intermittent small bowel bleeding who tested positive on a 99mTcpertechnetate scan for MD but who was later diagnosed with a bleeding ileal ulcer without MD, by capsule endoscopy.…”

Lower gastrointestinal bleed playing hide and seek

“…[ 2 ] Patients with ectopic gastric mucosa who bleed sporadically, may have false-negative 99m Tc-pertechnetate scintigraphy when performed during an active bleeding episode. [ 3 4 ] Necrosis of Meckel's diverticulum leads to the absence of or insufficient gastric mucosa to adequately concentrate the radioisotope. Furthermore, dilution of radioactivity in the small bowel due to hemorrhage, decreases the sensitivity of the study, thus hindering the diagnosis.…”