Benign mesothelial inclusions in a mediastinal lymph node

Abstract

Benign mesothelial proliferations found in lymph nodes present a diagnostic dilemma as they can mimic metastatic disease. There are only a few case reports of mesothelial proliferations in lymph nodes in the literature. We report our findings in a patient who developed heart failure and had an incidental mediastinal lymph node removed at the time of coronary artery by-pass graft and aortic valve replacement. Histologically the proliferations are characterised by epithelioid cells lacking atypia and which demonstrate an immunohistochemical profile characteristic of mesothelium. Incorrect diagnosis can lead to over-treatment and morbidity for the patient.