”Cat scratch” colon: an impressive but innocent endoscopic finding

We have read with great interest the article by McDonnell et al. [1] on a new endoscopic finding in the cecum and ascending colon, characterized by bright erythematous linear marks resembling scratches, thereby creating the neologism ”cat scratch” colon. Here we describe a similar case to expand the experience with this endoscopic entity.

A 74-year-old man with metastatic liver disease of unknown origin was referred for colonoscopy. The patient reported normal bowel habits. Physical examination revealed remarkable hematomegaly. There were no hematologic abnormalities and renal function was normal. Liver function tests revealed the following: serum bilirubin 1.2 mg/dL (normal range 0.2 - 1.2 mg/dL); alkaline phosphatase 198 U/L (normal range 40 - 120 U/L); γ-glutamyltransferase 273 U/L (normal range 20 - 40 U/L); alanine aminotransferase 148 U/L (normal range 10 - 40 U/L); aspartate aminotransferase 112 U/L (normal range 10 - 40 U/L). At colonoscopy multiple diverticula in sigmoid and descending colon were found. At intubation of the cecum, bright red linear marks with extravasation of fresh blood resembling ”scratches” ([Fig. 1 a] and b) were observed. Although we speculated that these lesions were caused by barotrauma [2] of the right colon from air insufflation into a less compliant right colon due to pressure from the metastatic liver, biopsies were taken from the site of the lesions and the results were normal.

Despite the impressive endoscopic picture, the ”cat scratch” colon finding is innocent because it is usually associated with normal histopathology or rarely with collagenous colitis [1].

Fig. 1 a, b Endoscopic view of the cecum showing bright red linear marks with extravasation of blood resembling ”scratches”.

Competing interests: None

References

• 1 McDonnell W M, Loura F, Pointon M J, Greenson J K. Cat scratch colon.  Endoscopy. 2007;  39 459-461
• 2 Woltjen J A. A retrospective analysis of cecal barotraumas by colonoscope air flow and pressure.  Gastrointest Endosc. 2005;  61 37-45