title: Primary mesenchymal tumors of the pancreas: single-center experience over 16 years.
abstract: OBJECTIVE
  Primary mesenchymal tumors of the pancreas are extremely rare and no comprehensive study of this class of tumors has been previously performed.
  
  
  METHODS
  Twenty cases of the primary mesenchymal tumors of the pancreas were selected and compared clinicopathologic variables with consecutively resected 500 pancreatic ductal adenocarcinomas.
  
  
  RESULTS
  Finally, 20 (0.3%) cases were confirmed as primary mesenchymal tumors. The 14 (70%) cases of benign/borderline tumors included 4 cases of fibromatoses, 2 cases of cavernous hemangiomas, 2 cases of schwannomas, 2 cases of solid and cystic hamartomas, 2 cases of solitary fibrous tumors, 1 case of inflammatory myofibroblastic tumor, and 1 case of angiomyolipoma. The 6 (30%) cases of sarcomas comprised 3 cases of undifferentiated/unclassified sarcomas, 1 case of leiomyosarcoma, 1 case of Ewing sarcoma/primitive neuroectodermal tumor, and 1 case of atypical lipomatous tumor/well-differentiated liposarcoma. When compared with the 500 ductal adenocarcinomas, the 3 surgically resected sarcomas were larger (mean, 5.8 cm vs 3.6 cm; P = 0.02); however, no difference in median survival time was observed between patients with sarcoma (23 months) and patients with ductal adenocarcinoma (16 months).
  
  
  CONCLUSIONS
  First, primary mesenchymal tumors of the pancreas are extremely rare. Second, several primary mesenchymal tumor types can be observed in the pancreas. Understanding these rare disease entities will help ensure their correct diagnosis.
authors.affiliation: From the Departments of *Pathology, †Radiology, ‡Hepatobiliary and Pancreas Surgery, and §Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Joo Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Joon Seon
authors.initials: JS
authors.lastname: Song
authors.forename: Hosub
authors.initials: H
authors.lastname: Park
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Byun
authors.forename: Ki-Byung
authors.initials: KB
authors.lastname: Song
authors.forename: Kyu-Pyo
authors.initials: KP
authors.lastname: Kim
authors.forename: Song Cheol
authors.initials: SC
authors.lastname: Kim
authors.forename: Seung-Mo
authors.initials: SM
authors.lastname: Hong
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D004252:DNA Mutational Analysis; D005260:Female; D005350:Fibroma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006391:Hemangioma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008648:Mesoderm / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D019009:Proto-Oncogene Proteins c-kit