Reactive Mesothelial Cells In Pleural Fluid Cytology

The distinction between reactive and malignant mesothelial cells has long been a challenge in effusion cytology.

Reactive mesothelial cells in pleural fluid cytology.

9 14 these studies suggest that 2. Because of the difficulty in distinguishing reactive mh from mm even in tissue specimens such as small pleural biopsies several studies have used immunohistochemical markers to distinguish between reactive and neoplastic mesothelial cells 3 8 or between adenocarcinoma reactive mh and mm in serous effusions. Hyperplastic mesothelial cells with slightly enlarged nuclei micronucleoli and a clear space or window between adjacent cells present singly and in small clusters. Normally mesotheial cells present only along surface and not in underlying tissue.

Larger clusters of hyperplastic mesothelial cells showing mildly nuclear atypia with small nucleoli. Epithelial or lining cells most commonly mesothelial cells 1 the appearance and presentation of nucleated cells found in pleural fluid and whether they are considered common benign or abnormal is discussed below. Numerous mesothelial cells are seen in this pleural fluid from a dog with a transudative effusion with concurrent diapedesis of red blood cells or hemorrhage. Reactive pleural effusion showing acute and chronic cells normal mesothelial cells and alveolar macrophages in aggregates and dispersed cells with rounded nuclei and vacuolated cytoplasm.

Neoplastic transformation of mesothelial cells results in malignant mesothelioma an aggressive tumor especially the pleura. The many faces of reactive mesothelial cells. Papanicolaou x100 breast adenocarcinoma cells in pleural effusion. An introduction to cytopathology is in the cytopathology article.

Reactive mesothelial cells reactive mesothelial cells in pleural fluid reactive mesothelial cells are found when there is infection or inflammation present in a body cavity. Many of the false positives in effusion fluid cytology are caused by the atypical features of reactive mesothelial cells associated with a variety of underlying benign processes including acute pancreatitis 2 tuberculosis 1 ovarian fibroma 1 pulmonary infarction 3 chemotherapy 4 and cirrhosis. Common cells present in pleural fluid include neutrophils lymphocytes monocytes mesothelial cells and red blood. Mesothelial cells form conspicuous layer of regularly spaced bland cuboidal cells along pleural surface.

The mesothelial cells have central round nuclei with a moderate amount of light purple cytoplasm and a corona or fringe to the cytoplasmic borders. Bap1 a new marker that is helpful in distinguishing reactive mesothelial cells from malignant mesothelioma. Mesothelial cytopathology is a large part of cytopathology.