Vij M, Veerankutty FH, Raju LP, Gowrishankar G, Rajalingam R, Jothimani D, Kaliamoorthy I, Rammohan A, Rela M. Frequent expression of PD-L1 in lymphocyte-rich hepatocellular carcinoma: A report of 4 cases.
Ann Diagn Pathol 2023;
66:152172. [PMID:
37348413 DOI:
10.1016/j.anndiagpath.2023.152172]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/09/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND
Programmed death ligand 1 (PD-L1) is an immune checkpoint inhibitor. PD-L1 binds to its receptor programmed death receptor (PD-1) expressed by immune cells and plays a key role in regulating immune responses. Engagement of PD-L1 on cancer cells and PD-1 on immune cells avoid destruction of tumour cells by immune cells. Immunostaining with PD-L1 has been suggested as a biomarker predictive of antiPD-L1 immunotherapy. Lymphocyte-rich hepatocellular carcinoma (LrHCC) is a rare histological HCC subtype which is characterised by neoplastic epithelial cells intermixed with numerous immune cells.
METHODS
Here in we investigated immunohistochemical PD-L1 expression in 4 cases of LrHCC. Tumour proportion score (TPS) and immune cell score was recorded. Immunophenotypic characterization of the tumour and inflammatory cells was also done. Epstein-Barr encoding region (EBER) in situ hybridization (ISH) assay as performed in all four tumours.
RESULTS
Expression of PD-L1 was demonstrated in tumour epithelial cells and immune cells in all four cases. Incomplete to membranous staining was demonstrated in the tumour cells. Tumour proportion score (TPS) was 1.2-20 %. Immune cells demonstrated membranous and cytoplasmic immunostaining. Immune cell score was ≥1 % to >10 %.
CONCLUSION
PD-L1 expression in both tumour and immune cells suggests distinct immunogenic feature and potential role of antiPD-L1 therapies in cases with inoperable disease.
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