title: [Clinicopathologic features of extrapulmonary inflammatory myofibroblastic tumor].
abstract: OBJECTIVE
  To investigate the clinicopathologic features, immunohistochemic phenotypes and genetic alterations of extrapulmonary inflammatory myofibroblastic tumor (IMT) and the correlation with prognosis.
  
  
  METHODS
  Thirty cases of IMT with follow-up were analyzed morphologically and immunohistochemically. ALK FISH was also performed to determine the ALK gene status.
  
  
  RESULTS
  Patients ranged in age from 12 to 73 years (mean 43.4 years). The male-to-female ratio was 1.0: 1.1. The tumors were located in various anatomical sites including gastrointestinal tract, liver, spleen, kidney, pelvic, retroperitoneum, mediastinum etc. Histologically, the majority of cases were composed of spindled fibroblastic and myofibroblastic cells accompanied by an inflammatory infiltrate of plasma cells, lymphocytes, and eosinophils. Most cases with aggressive behavior had features including prominent nucleoli and edematous myxoid background. Lymphohistiocytic reactions were usually absent. Some cases showed multinucleation, nuclear pleomorphism and mitoses. One case demonstrated epithelioid morphology with round-to-epithelioid cells. The immunohistochemical study showed vimentin, SMA, CK, desmin, and ALK were expressed in 100% (30/30), 70% (21/30), 13% (4/30), 27% (8/30), and 27% (8/30) of IMT, respectively. Diffuse cytoplasmic ALK staining was detected in seven cases. One case (containing round-to-epithelioid cells) demonstrated ALK nuclear membrane staining, coupled with positive reaction for CD30 and negative reaction for LCA. EMA, CD34, CD117 and S-100 protein, and MyoD1 were negative for all cases. Six ALK protein positive cases harbored ALK gene rearrangement, but not the remaining 22 cases. Follow-up data were available in 21 patients. After initial resection, 14 patients were alive with no evidence of disease, while 4 patients were alive with tumor recurrence and 3 patients died of the disease.
  
  
  CONCLUSIONS
  Most IMT with aggressive behavior have features including prominent nucleoli, edematous myxoid background, and positive expression of ALK. Lymphohistiocytic reaction is usually absent. ALK may be a potential novel therapeutic target for IMT.
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Huanping
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Qiuyuan
authors.initials: Q
authors.lastname: Xia
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Shi
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Rusong
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Henghui
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Pathology, Medicine School of Nanjing University/Nanjing Jinling Hospital, Nanjing 210002, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhou
authors.affiliation: E-mail: raoqiu1103@126.com.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Rao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000077548:Anaplastic Lymphoma Kinase; D002648:Child; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006104:Granuloma, Plasma Cell / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007249:Inflammation / Q000473:pathology; D008297:Male; D008875:Middle Aged; D058628:Myofibroblasts / Q000473:pathology; D011379:Prognosis; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D055815:Young Adult
chemical_list: C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases