Taskin OC, et al. - Six hundred and fifty-six gallbladder carcinomas (GBC) were evaluated by experts to determine the clinicopathologic characteristics of sarcomatoid carcinomas (recently seen via genetic profiling studies and also as a distinct model of epithelial-mesenchymal transition) of the gallbladder. There were 11 (nine females, two males) with a sarcomatoid component recognized and compared with ordinary GBC. Out of them, 9 presented with advanced stage (pT3/4) tumors. Nine patients had an adenocarcinoma component composing 1–75% of the tumor and eight had surface dysplasia/CIS with either in situ or invasive carcinoma observed in all patients. A pleomorphic–sarcomatoid pattern was exhibited by seven individuals; four had subtle/bland elongated spindle cells. The median Ki67 index was discovered to be 40%. The overall behavior was more serious than ordinary adenocarcinomas in general, however, it was not different when grade and stage were matched. Therefore, the sarcomatoid component was recognized in <2% of GBC. These were rarely of the “osteoclastic” type and subjects presented with large/advanced stage tumors, unlike sarcomatoid carcinomas in the remainder of the pancreaticobiliary tract. Moreover, these tumors were recognized as aggressive with active mortality, unlike pancreatic osteoclastic ones which usually had an indolent behavior.