Article Text

Download PDFPDF
PD-1 and PD-L1 expression in thymic epithelial tumours and non-neoplastic thymus
  1. Emine Kilic Bagir1,
  2. Arbil Acikalin1,
  3. Alper Avci2,
  4. Derya Gumurdulu1,
  5. Semra Paydas3
  1. 1 Department of Pathology, Faculty of Medicine, Cukurova University, Adana, Turkey
  2. 2 Department of Chest Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey
  3. 3 Department of Medical Oncology, Faculty of Medicine, Cukurova University, Adana, Turkey
  1. Correspondence to Dr Emine Kilic Bagir, Department of Pathology, Faculty of Medicine, Cukurova University, Adana 01130, Turkey; eminebagir{at}


Aims We explored the relationships between programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) expression and the pathological and clinical features of thymic epithelial tumours and thymic hyperplasia.

Methods We evaluated PD-1 and PDL-1 expressions within epithelial and microenvironmental components in thymic epithelial tumours (n=44) and thymic hyperplasias (n=8), immunohistochemically. We compared the results with demographic, clinical and histopathological features of the cases.

Results We found 48% epithelial expression and 82.7% microenvironment expression for PD-1 and 11.5% epithelial expression and 34.6% microenvironment expression for PD-L1. There was no PD-1 expression, in either the epithelial or microenvironment, in the thymic hyperplasia group. PD-1 and PD-L1 positivity was more significant in thymic epithelial tumours than thymic hyperplasia. Patients with PD-1-positive microenvironments exhibited significantly shorter mean estimated survival time than their negative counterparts.

Conclusion These findings suggest that anti-PD-1 and anti-PD-L1 therapies may benefit patients due to high release of PD-1 and PD-L1 in thymic epithelial tumours.

  • immunohistochemistry
  • tumour immunity
  • oncology

Statistics from


  • Handling editor Tahir S Pillay.

  • Competing interests None declared.

  • Ethics approval Cukurova University ethics committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Presented at This study was presented as a poster at the 26th National Pathology Congress 2–6 November 2016, Antalya, Turkey, and the 29th European Congress of Pathology 2–6 September 2017, Amsterdam, The Netherlands.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.