Fine-Needle Aspiration vs Surgical Pathology Specimens for PD-L1 Expression Evaluation
According to a quality assurance project, there was moderate concordance between cytology and surgical specimens when evaluating PD-L1 expression.
These data were first presented by Olabisi Afolayan-Oloye, MD, MPH, Temple University Hospital, Philadelphia, Pennsylvania, at the 2025 College of American Pathologists Meeting (CAP25) in Orlando, Florida.
This study included 12 cases of non-small cell lung (NSCLC) diagnosed via PD-L1 immunohistochemistry (IHC) and correlated with surgical specimens. The PD-L1 tumor proportion score (TPS) was considered to be negative with expression < 1% and positive with expression > 1%. Positive TPS was also categorized into < 50% and high expression with > 50%
Tumor sizes ranged from 1.0 to 9.3 cm and included squamous cell carcinoma (n = 3) and adenocarcinoma (n = 9). Of the 12 cases, 8 had PD-L1 scores that were concordant between cytology and surgical specimens (75%). Additionally, 4 cases expressed a higher PD-L1 score on the surgical specimens compared to the cytology. Study authors identified the challenges to concordance included “artifactual crowding after processing and background nontumoral cellularity.”
Dr Afolayan-Oloye et al concluded that these data “support the use of cytology specimens for initial assessment” adding “negative PD-L1 scores should be repeated for the surgical specimens.”
Source:
Afolayan-Oloye O, Akhtar I, and Gonzalez MF. Concordance of PD-L1 tumor proportion score between fine-needle aspiration and surgical pathology specimens in non-small cell carcinoma. Presented at CAP25 Meeting. September 13-16, 2025; Orlando, FL. Poster # 115
