Subepithelial tumours of the gastrointestinal tract can be benign, pre-malignant or malignant. Most small tumours are benign. Lipoma, leiomyoma, pancreatic rests or duplications cyst will usually not need further follow-up. Gastrointestinal stromal tumours or neuroendocrine tumours will require resection or surveillance. Metastasis to the gastrointestinal wall can rarely also present as subepithelial lesion.

Histology acquisition from subepithelial tumours is challenging as conventional endoscopic biopsies do usually not reach deeper than the mucosal layer. Subepithelial tumours often present a diagnostic dilemma.

The authors investigated the use, the safety and the diagnostic success of performing tunnel biopsies from subepithelial tumours to obtain histology.

Tunnel biopsy was defined as repeating at least 10 double pass biopsies targeting the identical spot on the subepithelial mass with conventional biopsy forceps. All patients with subepithelial tumours reported at oesophagogastroduodenoscopy presenting within the 6 year study period were included and data were analysed regarding size and location of the tumour, histology, radiological findings, re-admissions and adverse events.

Only in about half of the 229 encountered subepithelial tumours tunnel biopsies were attempted. However, when tunnel biopsies were performed, they were diagnostic in 53.6%. Adverse events were not observed.

Performing tunnel biopsies from subepithelial tumours during endoscopy prolongs the procedure only a few minutes but can save endoscopic ultrasound-guided sampling or the need for follow-up in about 50%.

Further randomized studies with cost-analysis should assess the diagnostic yield of tunnel biopsies performed at the index endoscopy compared with endoscopic ultrasound-guided sampling.