Keyhole biopsy: an easy and better alternative to fine-needle aspiration or Tru-cut biopsy of submucosal gastrointestinal tumors

I read with great interest the recent studies of Fernandez-Esparrach [1] and Philipper [2] on diagnosing gastrointestinal stromal tumors (GIST). I agree with their observations that endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is often hampered by the lack of sufficient tissue to allow histology and immunohistochemistry to be done and that Tru-cut biopsy is technically impossible when the endoscope is angulated.

I suggest a much simpler and more efficient method that uses an EUS-guided keyhole biopsy technique (EUS-KB). Four patients (mean age 68 years) with submucosal tumors had experienced unsuccessful attempts at tissue diagnosis by conventional upper endoscopic forceps biopsy and underwent EUS-KB. The anatomic sites of the lesions were the stomach (n = 2) and the duodenum (n = 2). Following EUS evaluation of the submucosal lesion, a needle knife was used to cut a small mucosal keyhole over the center of the lesion ([Fig. 1 a]).

Fig. 1 Keyhole biopsy of a submucosal gastrointestinal tumor. a Following endoscopic ultrasound evaluation of the submucosal lesion, a needle knife was used to cut a small mucosal keyhole over the center of the lesion. b A biopsy forceps was then introduced through the hole into the center of the lesion and multiple samples were obtained and placed in formalin.

A biopsy forceps was then introduced through the hole into the center of the lesion and multiple samples were obtained and placed in formalin ([Fig. 1 b]).

The mean procedure time was 31 minutes. There were no complications. Adequate specimens for histology, mitotic rate, and immunohistochemistry were obtained from all lesions, allowing a diagnosis in all patients. The tissue specimens measured 7 – 10 mm and showed no cautery artifacts. Pathology showed one benign lesion (fibroma) and three neoplastic lesions (two GIST, one gastrinoma). Surgical resection was performed in two patients and confirmed the EUS-KB diagnosis of GIST and gastrinoma. Therefore, EUS-KB may represent an easy and quick technique providing abundant histological tissue to accurately diagnose mesenchymal tumors.

Competing interests: None

References

• 1 Fernández-Esparrach G, Sendino O, Solé M. et al . Endoscopic ultrasound-guided fine-needle aspiration and trucut biopsy in the diagnosis of gastric stromal tumors: a randomized crossover study.  Endoscopy. 2010;  42 292-299
• 2 Philipper M, Hollerbach S, Gabbert H E. et al . Prospective comparison of endoscopic ultrasound-guided fine-needle aspiration and surgical histology in upper gastrointestinal submucosal tumors.  Endoscopy. 2010;  42 300-305