2016 Volume 55 Issue 3 Pages 142-147
Objective : The aim of the present study was to characterize the cytological features of reactive mesothelial cell clusters with collagenous stroma (RMCCs-CS) in malignant and non-malignant effusions in serous cavities.
Study Design : We analyzed the data of 200 patients with pleural effusion and 88 patients with ascites. Patients with and without malignant effusion were compared in terms of the incidence and number of RMCCs-CS per Papanicolaou-stained specimen, and in terms of the cytological features, such as the number of mesothelial cells in the RMCCs-CS, the number of layers in the RMCCs-CS, and the size of the collagenous stroma (CS).
Results : The incidence of RMCCs-CS was significantly higher in the malignant effusion group (20.9%) as compared to that in the non-malignant effusion group (p<0.001). The average number of RMCCs-CS detected per Papanicolaou-stained specimen in the malignant effusion group was 17.9, which was significantly higher than that in the non-malignant effusion group (p=0.012). The RMCCs-CS comprised fewer than 19 cells in 91.5% of patients and showed single-to double-layer formations in 94.7% of patients. The CS showed marked variations of size.
Conclusion : RMCCs-CS typically appeared as flat and small clusters in malignant effusion, which may represent an important cytological finding in malignant effusions.
