Indeterminate diagnosis in fine‐needle aspiration of the pancreas: Reasons and clinical implications

Abstract

An indeterminate diagnosis made on fine-needle aspiration (FNA) samples of the pancreatic lesions can cause dilemmas in clinical management. We retrospectively analyzed FNA features of such lesions in 65 consecutive pancreatic FNAs from 56 lesions to learn more about the sources of uncertainty and their clinical implications. A definitive diagnosis based on follow-up information was available in 50 lesions. Radiologically, 39% of the lesions showed a cystic component, and 25% of the lesions were ill-defined. Cytologically, contributing factors included scant atypical cells, coexistence of gastrointestinal epithelium, pancreatitis, poor cellular preservation, and interpretation error. Repeat sampling, as requested by clinicians prior to treatment, was performed in 33 (66%) of the 50 lesions, leading to a definitive pathologic diagnosis in 20 (61%) lesions. Seventeen lesions were eventually resected, of which a definitive preoperative diagnosis was attempted in 12 lesions via repeat sampling and was successful in seven. We concluded that indeterminate cytologic diagnosis of a pancreatic lesion often needs to be pursued for optimal management. Although intrinsic natures of a lesion such as cystic component may contribute to insufficient sampling, diagnostic certainty can be improved by proper specimen handling, interpretation, and clinical and/or radiographic correlation.

Blinded Prospective Comparison of the Performance of 22-Gauge and 25-Gauge Needles in Endoscopic Ultrasound-Guided Fine Needle Aspiration of the Pancreas and Peri-pancreatic Lesions

“…On follow-up, this individual ultimately did not have pancreatic carcinoma. Our findings confirm the greater cellularity expected for individuals with true malignancies (e.g., carcinoma) than for individuals without malignancy (e.g., pancreatitis) [2,10].…”

“…It is widely accepted that cellular discohesion, necrosis, and nuclear atypia are cytologic features that contribute to a diagnosis of malignancy [2,10]. Furthermore, the presence of these features can lower the cellularity required for a confident malignant interpretation.…”

“…During the EUS examination, FNA can be performed on visible masses, nodules, and/or lymph nodes under ultrasound guidance with little risk of complication [1]. Although the accuracy of FNA has improved along with advances in obtaining and processing specimens, indeterminate (suspicious for malignancy) and false-negative diagnoses are still a significant concern [2][3][4][5][6][7][8][9][10].…”

Endoscopic ultrasound‐guided pancreatic fine‐needle aspiration: Potential pitfalls in one institution's experience of 1212 procedures

“…In our experience, one of the major challenges in pancreatic EUS‐FNA has been distinguishing mucinous neoplasms, especially IPMN, from gastric foveolar cell contaminants in cases of transgastric EUS‐FNA. This has been a concern in studies by many others as well . The general consensus is that there is no single cytomorphologic feature that can reliably separate gastric foveolar cells from the low‐grade neoplastic cells in the gastric foveolar type of IPMN.…”

Fluorescence In Situ Hybridization and K-ras Analyses Improve Diagnostic Yield of Endoscopic Ultrasound-Guided Fine-Needle Aspiration of Solid Pancreatic Masses

“…There have been variable reports on the incidence of atypical cell diagnosis after EUS-FNA. 3,8,9 Atypical cell diagnosis creates a difficult management dilemma as this diagnosis is considered insufficient for initiation of chemotherapy or for surgery. Notably, most atypical cell diagnoses have been determined to be malignant on clinical follow-up or repeat aspirations.…”