DESMOPLASTIC STROMA IDENTIFICATION AS A QUALITY MARKER FOR RELIABLE HISTOLOGIC SAMPLES OBTAINED BY EUS IN SOLID PANCREATIC LESIONS. A NEW STANDARD FOR ADEQUACY

Aims To evaluate the presence of desmoplastic stroma as a potential new quality marker of the fine needle biopsy (FNB) samples in pancreatic ducal adenocarcinoma (PDAC). To illustrate that a simplified strategy to obtain and process the tissue using histologic needles allows an adequate high-quality sample, including the identification of stroma.

Methods We retrospectively analyzed the global diagnostic performance and the presence of desmoplastic stroma in consecutive FNB samples of solid pancreatic lesions clinically suspicious of PDAC. We included those lesions starting after the switch from cytologic-based (FNA) samples to those obtained using histologic needles (FNB), and processed straightforwardly as a usual biopsy, what we defined as “simplified biopsy”, namely to directly express the tissue in formalin, doing a rapid first adequacy assessment according to macroscopic on-site evaluation (MOSE) as described in the literature. 22G caliber Franseen and fork-type needles were used.

Results

Table 1

ANALYSED VARIABLE	FREQUENCY: Mode (n)
Tip design	Franseen 22G (14)
Number of passes	3 (9), range 2-4
Adequacy to diagnose PDAC	YES: 100% (15)
Visible desmoplastic stroma	YES: 100% (15)

From January 2020 to August 2021, fifteen consecutive purely solid and 5 solid-cystic lesions were diagnosed as PDAC using the simplified biopsy strategy. Diagnostic accuracy was 100%. Desmoplastic stroma was identified in all the samples from solid lesions.

Fig. 1

Conclusions Identification of desmoplastic stroma could work as a new specific quality marker for FNB samples, as it represents a more reliable feature of a PDAC lesion in terms of molecular microenvironment. This could facilitate ancillary tests aimed at stromal therapeutic targets including the design of organoids. A simplified biopsy strategy allows to easily obtain high quality histologic specimens with a complete diagnostic yield.

Publication History

Article published online:
14 April 2022