Evaluation of fine‐needle core biopsy specimens for pancreatic ductal adenocarcinoma: Diagnostic utility and helpful histological features

Aims With the advent of new biopsy devices, fine‐needle core biopsy specimens can be obtained from pancreas masses. This study aimed to report the histological spectrum of intrapancreatic adenocarcinoma on fine‐needle core biopsy and the accuracy of sampling. Methods and results We identified 423 SharkCore™ fine‐needle core biopsies taken from patients with a high clinical concern for pancreatic adenocarcinoma. For each, we recorded patient age and sex, percentage of diagnostic tissue in each sample and tumour site, size and histological findings. The cases came from 392 patients (193 men, 199 women; mean age 69 years). Median diagnostic tissue amount in the samples was 30%. Common histological findings included desmoplasia (36%), single atypical cells (44%), haphazard glandular growth pattern (68%), nuclear pleomorphism > 4:1 (39%), incomplete gland lumens (18%) and detached atypical epithelial strips (37%). Additional levels were ordered on 143 cases. Final clinical diagnoses associated with the 423 cases were adenocarcinoma (n = 343), pancreatitis (n = 22), intraductal neoplasm or other benign/low‐grade process (n = 16) and unknown (n = 42, patients lost to follow‐up). Of the adenocarcinoma cases, the diagnosis was established by the evaluated fine‐needle core biopsy sample alone in 178, by fine‐needle aspiration biopsy alone in 30, by both concurrently in 89 and by subsequent biopsy or resection in 37 cases. Among 68 cases called suspicious on fine‐needle core biopsy, 78% ultimately represented adenocarcinoma. Conclusions Fine‐needle core biopsy allows for histological diagnosis of pancreatic adenocarcinoma, using known histological parameters. Common findings include single atypical cells, desmoplasia, haphazard gland growth and nuclear pleomorphism. Cases interpreted as suspicious often represent malignancy. In our cohort of 423 fine‐needle core biopsies of the pancreas, the median diagnostic tissue amount was 30%. Common histological findings included desmoplasia (36%), single atypical cells (44%), haphazard glandular growth pattern (68%), nuclear pleomorphism > 4:1 (39%) and incomplete gland lumens (18%). A total of 343 (81%) were linked to a final clinical diagnosis of adenocarcinoma, and among 68 cases called suspicious on biopsy, 78% ultimately represented adenocarcinoma.