This spectacular case is an example of an inflammatory myofibroblastic tumor centered in the gallbladder. Note that there is abundant keratin expression (there was also actin expression), which can be a pitfall. The myofibroblastic cells show macronucleoli, a typical feature. Note also the background inflammatory mix.
Case provided by Dr. Elizabeth Montgomery, Professor of Pathology and Vice Chair of Anatomic Pathology at the University of Miami, and Editor-In-Chief at Innovative Science Press. You can check out her GI and Soft Tissue volumes as well as our other titles at: