Fluorescence cytology with 5-aminolevulinic acid in EUS-guided FNA as a method for differentiating between malignant and benign lesions (with video)

Abstract

Background: EUS-guided FNA (EUS-FNA) has been increasingly performed to obtain specimens for the pathological evaluation of patients with GI and pancreaticobiliary masses as well as lymphadenopathies of unknown origin. Photodynamic diagnosis by using 5-aminolebulinic acid (ALA) has been reported to be useful for enabling the visual differentiation between malignant and normal tissue in various cancers.

Objective: To evaluate the diagnostic accuracy of fluorescence cytology with ALA in EUS-FNA.

Design: A prospective study.

Setting: A single center.

Patients: A total of 28 consecutive patients who underwent EUS-FNA for the pathological diagnosis of a pancreaticobiliary mass lesion or intra-abdominal lymphadenopathy of unknown origin.

Interventions: Patients were orally administered ALA 3 to 6 hours before EUS-FNA. The sample was obtained via EUS-FNA for fluorescence cytology and conventional cytology. A single gastroenterologist performed the fluorescence cytology by using fluorescence microscopy after the procedure, independently of the conventional cytology by pathologists.

Main outcome measurements: The accuracy of fluorescence cytology with ALA in the differentiation between benign and malignant lesions by comparing the results of fluorescence cytology with the final diagnosis.

Results: Of the 28 patients included in the study, 22 were considered as having malignant lesions and 6 patients as having benign lesions. Fluorescence cytology could correctly discriminate between benign and malignant lesions in all patients. Therefore, both the sensitivity and specificity of fluorescence cytology were 100% in our study.

Limitations: Fluorescence cytology was performed by only 1 gastroenterologist with a small number of patients.

Conclusion: Fluorescence cytology with ALA in EUS-FNA may be an effective and simple method for differentiating between benign and malignant lesions.