[Double-negative αβ T lymphocytes: What are the etiological considerations?].

INTRODUCTION

Double-negative T lymphocytes with αβ TCR (CD3+CD4-CD8-TCRαβ+) are a population of T cells present in low proportions in the blood under normal conditions. They can be abnormally elevated in various pathological situations.

CASE REPORT: A 64-year-old female patient was hospitalized due to a general deterioration of health. Laboratory tests revealed a monoclonal proliferation of double-negative αβ T lymphocytes, representing 28% of T cells (219/mm3). A thoraco-abdomino-pelvic CT scan revealed two suspicious intrahepatic masses, multiple enlarged lymph nodes, and peritoneal nodules. These lesions were hypermetabolic on 18FDG PET scan. A biopsy of the hepatic masses showed histological features consistent with cholangiocarcinoma.

CONCLUSION

We report a case illustrating how the investigation of a proliferation of double-negative αβ T lymphocytes led to the diagnosis of cholangiocarcinoma. Although a direct link between the two cannot be proven, we hypothesize that tumor antigenic stimulation selected a T lymphocyte clone.