Endoscopic Tattooing Site Presenting as Colonic Pseudotumor

Abstract

Purpose: Endoscopic tattooing is performed to facilitate identification of gastrointestinal lesions at follow-up endoscopy or surgery. We present a rare complication of endoscopic tattooing presenting as inflammatory pseudotumor. Case: A 62-year-old male presented with painless hematochezia and acute blood loss anemia. The patient had undergone colonoscopy with polypectomy 2 days prior to admission. During polypectomy, piecemeal resection of a large 2-cm sessile serrated adenoma was performed in the ascending colon. Proximal and distal ends of the polypectomy site were tattooed by injecting a sterile suspension of highly purified carbon particles (SPOT ink). A repeat colonoscopy was performed after admission for likely post-polypectomy bleed. A large amount of fresh blood was seen throughout the colon. Recent polypectomy site was identified in the ascending colon with ulceration and an adherent clot. The clot was dislodged and a visible vessel with active bleeding was seen. Hemostasis was achieved by injecting 1:10,000 diluted epinephrine and placing three endoclips on the bleeding lesion. Incidentally, a second large ulcer (1.5 x 1.0 cm in size) with heaped-up margins and surrounding induration was noted just proximal to the polypectomy site. This was the area of recent endoscopic tattooing with blue-black discoloration of the colonic mucosa and the ulcer crater. Conclusion: Endoscopic tattooing is an effective technique to mark gastrointestinal lesions by submucosal dye injection. It is a safe procedure; however, rare complications (focal peritonitis, abscess formation, infected hematomas, perforation) have been reported. Tattooing agents may elicit inflammation, thrombosis, and fibroblast proliferation resulting in fat necrosis and ulceration at the injection site. It is important for endoscopists to be aware of the potential localized tissue injury induced by endoscopic tattooing because it can mimic malignancy.