title: Rhabdomyosarcomatous Transformation of a Gastrointestinal Stromal Tumor following Treatment with Imatinib.
abstract: Rhabdomyosarcomatous dedifferentiation of GIST following tyrosine kinase inhibitor (TKI) therapy is rare, with only a handful of cases previously reported in the literature. Herein we present a case of metastatic GIST initially treated with imatinib that developed radiographic evidence of progression after 8 months of standard dose therapy with continued progression despite attempts at using dose-escalated imatinib 400 mg bid. Due to the patient's worsening clinical symptoms and radiographic concerns for colonic thickening, abscess, and extraluminal air, the patient underwent a palliative resection of a large heterogeneous mass arising from the posterior stomach and several metastatic foci. Pathology revealed a dedifferentiated GIST with rhabdomyosarcomatous features. This report will highlight the unique features of this case and review the existing literature.
authors.affiliation: Department of Pathology, Duke University, DUMC Box 3712, Durham, NC 27710, USA.
authors.forename: Xiaoyin
authors.identifier: 0000-0002-3069-3130
authors.initials: X
authors.lastname: Jiang
authors.affiliation: St. George's University, St. George, Grenada.
authors.forename: H Bryan
authors.initials: HB
authors.lastname: Anderson
authors.affiliation: Department of Pathology, Duke University, DUMC Box 3712, Durham, NC 27710, USA.
authors.forename: Cynthia D
authors.initials: CD
authors.lastname: Guy
authors.affiliation: Department of Surgery, Duke University, 3116 North Duke Street, Durham, NC 27704, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mosca
authors.affiliation: Department of Medicine, Duke University, DUMC Box 3198, Durham, NC 27710, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Riedel
authors.affiliation: Department of Pathology, Duke University, DUMC Box 3712, Durham, NC 27710, USA.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Cardona