title: Malignant stromal tumor of the gallbladder with interstitial cells of Cajal phenotype.
abstract: Malignant mesenchymal tumors of the gallbladder are exceedingly rare. We report a malignant stromal tumor of the gallbladder with a phenotype of interstitial cells of Cajal. To our knowledge, only the benign counterpart of this tumor has been described previously. A 34-year-old woman presented with right upper quadrant abdominal pain. At the time of cholecystectomy, the gallbladder was noted to have a thickened wall and a polypoid mass arising in the neck of the gallbladder. Histologic sections showed a cellular proliferation of spindle neoplastic cells that were arranged in short fascicles. Numerous mitotic figures and foci of necrosis were noted. The neoplastic cells expressed CD117 (c-Kit protein) and vimentin. They were negative for smooth muscle actin, desmin, myoglobin, cytokeratin, S100 protein, and CD34. Our case demonstrates that a malignant stromal tumor that is histologically and immunohistochemically identical to gastrointestinal stromal tumor can occur in the gallbladder, and that the expression of CD117 may be of therapeutic importance.
authors.affiliation: Department of Pathology, Regional General Hospital, Social Security System, Mexico City, Mexico.
authors.forename: Marisela
authors.initials: M
authors.lastname: Mendoza-Marin
authors.forename: Mai P
authors.initials: MP
authors.lastname: Hoang
authors.forename: Jorge
authors.initials: J
authors.lastname: Albores-Saavedra
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D005706:Gallbladder Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007124:Immunoenzyme Techniques; D009197:Myenteric Plexus / Q000473:pathology*; D009442:Neurilemmoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D017154:Stromal Cells / Q000473:pathology*; D014746:Vimentin / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D014746:Vimentin; D019009:Proto-Oncogene Proteins c-kit