Abstract
Due to the difficulty in differentiating between reactive mesothelia (RM) and epithelial malignant mesothelioma (EMM) in effusion cytology, we attempted to distinguish EMM from RM cytologically.
The 12 cytomorphological parameters we studied in 15 EMM and 17 RM cases were (1) cell arrangement, (2) cytoplasmic thickness, (3) nuclear size variability, (4) nuclear size, (5) number of nuclei, (6) nuclear shape, (7) nuclear irregularity, (8) chromatin pattern, (9) number of nucleoli, (10) mitotic figures, (11) cell-to-cell apposition, and 12) intracytoplasmic vacuoles.
Cell in EMM were predominantly arranged in clumps, showed a wide range of sizes, and frequently had multiple nuclei. Cells in RM alone had no apparent nucleolus and were typically solitary. In EMM, mitotic figures were seen more frequently, as were intracytoplasmic vacuoles.
In conclusion, cell arrangements and intracytoplasmic vacuoles were most useful for differential diagnoses, and nuclear size variability, nuclear size, number of nuclei, number of nucleoli, and mitotic figures were highly useful.
