title: Visceral clear cell sarcoma of soft tissue with confirmation by EWS-ATF1 fusion detection.
abstract: Clear cell sarcoma of soft tissue (CCS-ST) is a rare malignant neoplasm characterized by a tumor-defining translocation [t(12;22) (q13;q12)], resulting in the EWS-ATF1 gene fusion. An extremely limited number of visceral CCS-ST cases have been reported in the literature. Here the authors report a visceral CCS-ST in a Hispanic adolescent male with a large infiltrative mass involving the small bowel. The tumor was evaluated by light microscopy, immunocytochemistry, electron microscopy, cytogenetics, and molecular genetics. The tumor cells were strongly positive for S-100 protein, but negative for HMB-45. Rare premelanosomes were identified only after an extensive search with electron microscopy. Cytogenetics showed a characteristic t(12;22)(q13;q12) for CCS-ST with isochromosome 18q and trisomy 22. An EWS exon 8 sense primer and an antisense ATF1 primer were employed for detection of the CCS-ST tumor-defining EWS-ATF1 translocation, using reverse transcriptase-polymerase chain reaction techniques (RT-PCR), and the fusion gene breakpoint underwent DNA sequencing. This tumor is exceptional, because it is the first visceral CCS-ST that has been confirmed by RT-PCR and DNA sequencing. This case also illustrates the necessity of a multimodal approach to tumor diagnosis, and the utility of cytogenetics and molecular pathology in confirming the diagnosis of CCS-ST and eliminating conventional metastatic or primary visceral malignant melanoma as a consideration.
authors.affiliation: Department of Pathology, Texas Children's Hospital, Baylor, College of Medicine, Houston, Texas 77030-2313, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Granville
authors.forename: John
authors.initials: J
authors.lastname: Hicks
authors.forename: Edwina
authors.initials: E
authors.lastname: Popek
authors.forename: Megan
authors.initials: M
authors.lastname: Dishop
authors.forename: Nina
authors.initials: N
authors.lastname: Tatevian
authors.forename: Dolores
authors.initials: D
authors.lastname: Lopez-Terrada
mesh_terms: D000293:Adolescent; D018798:Anemia, Iron-Deficiency / Q000175:diagnosis; D014408:Biomarkers, Tumor / Q000378:metabolism; D020732:Cytogenetic Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D007414:Intestinal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000556:secondary; D015514:Oncogene Proteins, Fusion / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018227:Sarcoma, Clear Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017422:Sequence Analysis, DNA; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C111598:EWS-ATF1 fusion protein, human; D015514:Oncogene Proteins, Fusion; D014157:Transcription Factors