title: [Alveolar soft part sarcoma: a clinicopathologic analysis of 48 cases].
abstract: OBJECTIVE
  To study the clinicopathologic features and differential diagnosis of alveolar soft part sarcoma (ASPS).
  
  
  METHODS
  The clinical data and pathologic features of 48 cases of ASPS were evaluated. Immunohistochemical study, PAS staining and fluorescence in-situ hybridization (FISH) were carried out in selected examples. Relevant literature was reviewed.
  
  
  RESULTS
  Amongst the 48 cases studied, there were 17 males and 31 females, with male-to-female ratio of 1.0∶1.8. The age of patients ranged from 2 to 60 years (median=26 years). The tumor was most commonly located in deep soft tissue, especially that of lower extremities. Histologically, the tumor cells were arranged in alveolar or solid patterns and separated by sinusoidal vessels. They were large and contained abundant eosinophilic granules or crystals in cytoplasm. The nuclei were round to polygonal and vesicular, often with prominent nucleoli. Intravascular tumor extension was common. Some cases showed necrosis, hemorrhage and cystic changes. Immunohistochemical study showed that the tumor cells were positive for TFE3 (100%, 33/33). FISH assay was carried out in 4 cases and all of them had TFE3-ASPL gene fusion.
  
  
  CONCLUSIONS
  ASPS is a rare malignant neoplasm, often occurs in young patients. TFE3 is a useful immunohistochemical marker for diagnosis. The diagnosis is further confirmed by other markers.
authors.affiliation: Department of Pathology, Nanjing General Hospital of Nanjing Command, Nanjing 210002, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng
authors.forename: Pin
authors.initials: P
authors.lastname: Tu
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.forename: Qiu
authors.initials: Q
authors.lastname: Rao
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Zhou
authors.forename: Qunli
authors.initials: Q
authors.lastname: Shi
mesh_terms: D000293:Adolescent; D000328:Adult; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D050939:Gene Fusion; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D018234:Sarcoma, Alveolar Soft Part / Q000175:diagnosis* / Q000473:pathology*; D055815:Young Adult
chemical_list: C422743:ASPSCR1 protein, human; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D047908:Intracellular Signaling Peptides and Proteins; D015514:Oncogene Proteins, Fusion