title: Recurrent retroperitoneal extra-GIST with rhabdomyosarcomatous and chondrosarcomatous differentiations: a rare case and literature review.
abstract: Selective tyrosine kinase inhibitor (TKI) targeting KIT and PDGFRA is the frontline therapy for metastatic and unresectable GIST patients. Some initially responsive patients experience tumor progress because of secondary drug resistance, and some cases can develop heterogeneous differentiation. Here we report a rare case of recurrent retroperitoneal extra-GIST with rhabdomyosarcomatous and chondrosarcomatous differentiation with TKI therapy after surgical tumorectomy. Histology, immunohistochemistry, and mutational analysis were performed on primary and recurrent samples. The current case represents the first report of a recurrent retroperitoneal extra-GIST harboring mixed morphologic phenotypes of rhabdomyosarcoma and chondrosarsoma after TKI treatment. The dual differentiation can represent diagnostic pitfall.
authors.affiliation: Institute of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Department of Oncology, Zhongshan Hospital of Hubei Province Wuhan 430000, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Fei
authors.affiliation: Institute of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, China.
authors.forename: Yue'e
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, China.
authors.forename: Qilin
authors.initials: Q
authors.lastname: Ao
authors.affiliation: Institute of Pathology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Wang
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis; D004252:DNA Mutational Analysis; D017809:Fatal Outcome; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D000068877:Imatinib Mesylate / Q000627:therapeutic use*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D012186:Retroperitoneal Neoplasms / Q000188:drug therapy / Q000473:pathology*
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D047428:Protein Kinase Inhibitors; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit
keywords: Extragastrointestinal stromal tumor; chondrosarcoma; heterogeneous differentiation; rhabdomyosarcom; tyrosine kinase inhibitor