Reply to Grubel et al.

We greatly appreciate the conclusive technique called the endoscopic ultrasonography (EUS) keyhole biopsy technique proposed by Peter Grubel. Facing the situation of suboptimal EUS-guided fine needle aspirates, as we have shown in our series with a miss rate of up to 40 % for the additional immunocytochemical analysis, new techniques are crucial to overcome this situation.

But first going back to our discussion, beside the issue of inferior aspiration samples the question was in which situations do we need cytology for submucosal tumor management? We support the current practice of removing tumors larger than 2 – 3 cm and surveying smaller tumors, keeping the mitotic rates in mind. So histology will not be needed on a routine basis. In this respect Lee et al. recently demonstrated a similar even more invasive technique [1]. However, in addition to the small number of patients in this study, we also doubt the bleeding rate, and it seems controversial to just chop off a possible malignant tumor in the gastrointestinal tract rather than resect it.

To conclude, we fully agree that this keyhole technique might provide important information in special clinical situations, although more data about the value of information in a clinical setting and the risks, particularly bleeding rates, should be provided.

Competing interests: None

References

• 1 Lee C K, Chung I K, Lee S H. et al . Endoscopic partial resection with the unroofing technique for reliable tissue diagnosis of upper GI subepithelial tumors originating from the muscularis propria on EUS.  Gastrointest Endosc. 2010;  71 188-194