Cellularity improvement of EUS-FNB specimens for pancreatic adenocarcinoma using CytoMatrix

Aims Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) is the best way to targeting and sampling pancreatic lesions although without optimal results with diagnostic accuracy ranging from 80-95% because of the high desmoplastic reaction, inflammatory and necrotic content. The leght, nuumber and quality of histologic cores as well as the cellularity obtained on the EUS-FNB samples are crucial for diagnostic improvement as well as for ancillary genetic analyses. Polymeric matrices (such as CytoMatrix) were recently proposed for the collection of specimens for diagnostic purposes. The aim of this study is to investigate the adequacy, number and length of histological micro fragments and cellularity of the specimens carried out on 22 FNB samples included in CytoMatrix as compared with passages scattered in formalin.

Methods From November 2023 to September 2024 consecutive patients underwent to EUS FNB 22 gauge (Acquire Boston Scientific) for pancreatic ductal adenocarcinoma (PDAC) were enrolled. were enrolled. A single Endosonographer performed all the exams in deep sedation (spontaneous breathing) with a linear Ultrasound Endoscope. Two passes were performed, one included in CytoMatrix (CM), and the other was scattered in formalin (FM). All specimens were evaluated blindly by two pathologists (PE and CT) with experience in pancreatic diseases. The quality of specimens obtained was assessed based on a histology score, for comparison purposes, in four classes. The cellularity of each sample was also assessed by counting the neoplastic cells in both samples (CM and FM).

Results Twenty patients underwent EUS –FNB for PDAC were enrolled. Six female, Mean age 71 yrs (40-85), 17 lesions were localized in the head. The overall diagnostic accuracy of FNB was 95%. Two passes included in Cytomatrix and one in formalin were not diagnostic, with a diagnostic accuracy of 90% and 95% respectively. Histological specimens were obtained in 16 FNB passes included in CM versus 15 in FM and median of 3 mm in length of microfragments were obtained in CM (range 0-5 mm) versus 4 mm (range 0-10) in FM without significant different results in the two groups (P=0.4). The cellularity of each pass showed a median of 100 and 500 representative cells procurements when included in Cytomatrix versus less than 100 representative cells in the sample in FM (P=0.03).

Conclusions EUS-FNB, as expected, showed a high diagnostic accuracy. No differences in terms of adequacy, number and length of histological microfragments were observed in samples included in CytoMatrix as compared with formalin.A higher representative neoplastic cellularity was found in CytoMatrix samples. Since the quantity of tumour cells obtained is crucial for successful genomic analysis such as NGS, this results could impact on procedural outcomes for molecular profiling and therapeutic stratification markers on FNB specimens in PDAC.

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Artikel online veröffentlicht:
27. März 2025