Probe-based confocal laser endomicroscopy versus biopsies in the diagnostics of oesophageal and gastric lesions: A prospective, pathologist-blinded study

Abstract

Background and aim: Probe-based confocal laser endomicroscopy (pCLE) provides real-time microscopic visualisation. Our aim was to compare the diagnostic accuracy of pCLE with standard biopsies in patients with visible oesophageal or gastric lesions.

Methods: This was a single-centre, prospective, pathologist-blinded study. Patients underwent high-resolution endoscopy, and lesions were examined by pCLE followed by standard biopsies. A definitive diagnosis was determined from resection specimen. Main outcomes were overall diagnostic accuracy, sensitivity, specificity and positive and negative predictive values.

Results: We examined 74 lesions in 67 patients. Definitive diagnoses revealed 34 malignant and 40 non-malignant lesions. pCLE diagnosis was correct in 89.2% (66/74), while diagnosis based on biopsy was correct in 85% (57/67; p = 0.6). The overall diagnostic accuracy of biopsies was 85% (76-94%) and that of pCLE was 89% (79-96%). pCLE correctly diagnosed malignant lesions, comprising oesophageal adenocarcinoma, oesophageal squamous-cell cancer or gastric adenocarcinoma, in 88.2% (30/34) of cases, while biopsy was correctly diagnosed in 75.9% (22/29; p = 0.3). Sensitivity and specificity to diagnose a malignant lesion were 75.9% (95% confidence interval (CI) 56-89%) and 100% (95% CI 90-100%) for biopsies and 88.2% (95% CI 72-97%) and 92% (95% CI 79-98%) for pCLE. No differences between biopsies and pCLE were found with regard to sensitivity, specificity to diagnose dysplastic and benign lesions (p > 0.2).

Conclusion: pCLE provides satisfactory diagnostic accuracy comparable with standard biopsies in patients with oesophageal or gastric lesions. ClinicalTrials.gov identifier: NCT0292049).

Trial registration: ClinicalTrials.gov NCT02922049.

Keywords: Confocal laser endomicroscopy; oesophageal and gastric cancer.

Figure 1.

Granular cell tumour, Abrikossoff’s tumour (left: endoscopy with the lesion; middle: standard histopathology; right: pCLE). Correct diagnosis was made by both pCLE and histology. pCLE: probe-based confocal laser endomicroscopy.

Figure 2.

Agreement in the diagnosis in a patient with Barrett’s oesophagus (left: high-grade dysplasia (HGD), standard histopathology; right: HGD, pCLE). 1. Unequal luminal surface in dysplastic gland. 2. High activity of dysplastic cells (left: nucleocytoplasmic ratio increased; right: dark cells).

Figure 3.

Agreement in the diagnosis (left: standard histopathology; right: pCLE). 1. Serrated hyperplastic gastric epithelium with low-grade dysplasia; right: unequal epithelium structures of the serrated adenoma.

Figure 4.

Incorrect diagnosis by pCLE (left: gastritis, standard histopathology; right: dysplastic appearance, pCLE); correct diagnosis was gastritis. 1. Unequal luminal surface in dysplastic gland. 2. High activity of cells influenced by inflammation (left: nucleocytoplasmic ratio increased; right: dark cells).