1. Multilayered cell balls, smooth outlines, psammoma body 2. Acini in CB @kriyer68 @smlungpathguy @VijayPatho
![Image](https://pbs.twimg.com/media/ENcVy64UwAApPd2.jpg)
![Image](https://pbs.twimg.com/media/ENcVzvFU8AEGv3J.jpg)
* Proliferation spheres (cell balls) are solid with stromal cores in mesotheioma unlike carcinoma
* Mesothelial cells: peripheral condensed cytoplasm, vacuoles (intercellular windows)
![Image](https://pbs.twimg.com/media/ENhotg6UcAAXV7j.jpg)
* In peritoneal effusion however, PsB may be associated with benign mesothelial hyperplasia, endometriosis etc
* Not all ca. show cell balls- SCC, ILC, Signet ring ca