Monarch Disease Ontology id MONDO_0002857 (gallbladder sarcoma) is a malignant soft tissue neoplasm that arises from the gallbladder. Representative examples include Kaposi sarcoma, leiomyosarcoma, and rhabdomyosarcoma. Also known as: gall bladder sarcoma, malignant mesenchymal tumor of gallbladder, malignant mesenchymal tumour of gallbladder, sarcoma of gall bladder, sarcoma of gallbladder, sarcoma of the gallbladder.