title: EWS-ATF1 fusion transcripts in gastrointestinal tumors previously diagnosed as malignant melanoma.
abstract: BACKGROUND
  Clear cell sarcoma (CCS) is classically a deep soft tissue tumor associated with tendons or aponeuroses, although cases of primary CCS of the gastrointestinal (GI) tract have recently been reported. Because it is difficult to distinguish CCS from metastatic melanoma based on morphology, immunohistochemical profile, and ultrastructural features, it is possible that some GI tumors diagnosed as metastatic melanoma actually represent primary GI CCS. Because the EWS-ATF1 fusion transcript and the associated t(12;22)(q13;q12) translocation occur in CCS but not cutaneous melanoma, we investigated the use of molecular-based testing for discriminating CCS from metastatic melanoma (MM) in GI tumors.
  
  
  METHODS
  Patients with GI tumors diagnosed as MM were identified from departmental files. The tumors were tested for the EWS-ATF1 fusion transcript by RT-PCR and for t(12;22)(q13;q12) by fluorescence in situ hybridization.
  
  
  RESULTS
  Detailed review of medical records revealed that 16 (80%) of the 20 had a documented history of cutaneous melanoma. Two cases (10%) harbored the EWS-ATF1 fusion transcript, and fluorescence in situ hybridization confirmed the presence of t(12;22) in both cases. Of the 2 positive tumors, 1 developed in a patient who had no history of cutaneous melanoma, and the other developed in a patient with a remote history of vulvar melanoma.
  
  
  CONCLUSIONS
  Based on molecular genetic findings, a subset of GI tumors diagnosed as MM by routine histopathologic evaluation represents CCS.
authors.affiliation: Lauren V. Ackerman Laboratory of Surgical Pathology, Washington University School of Medicine, St. Louis, MO 63110-1093, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Covinsky
authors.forename: Steven
authors.initials: S
authors.lastname: Gong
authors.forename: Veena
authors.initials: V
authors.lastname: Rajaram
authors.forename: Arie
authors.initials: A
authors.lastname: Perry
authors.forename: John
authors.initials: J
authors.lastname: Pfeifer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D003937:Diagnosis, Differential; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008545:Melanoma / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018227:Sarcoma, Clear Cell / Q000235:genetics* / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology; D014157:Transcription Factors
chemical_list: C111598:EWS-ATF1 fusion protein, human; D015514:Oncogene Proteins, Fusion; D014157:Transcription Factors