title: A novel case of synovial sarcoma of the kidney: impact of SS18/SSX analysis of renal hemangiopericytoma-like tumors.
abstract: We report a new case of synovial sarcoma of the kidney. The patient underwent nephrectomy because of a large tumor in the right kidney. The histologic diagnosis was hemangiopericytoma. Less than 1 year after primary surgery the patient was reoperated due to massive local recurrence. Histology now revealed a poorly differentiated tumor tissue with hemangiopericytoma-like features. Immunostainings showed immunoreactivity to cytokeratin, epithelial membrane antigen, and vimentin. The tumor was negative to CD34 and factor VIII. The tumor cell proliferation, assessed by Ki-67, was high. RT-PCR analysis and sequence analysis demonstrated the presence of SS18/SSX2 fusion gene. Review of the histologic specimens from the original tumors confirmed hemangiopericytoma-like morphology. The new diagnosis was poorly differentiated synovial sarcoma. At the time of reoperation, lung metastases were detected radiologically, reflecting a very aggressive phenotype. To our knowledge, this is the third case of poorly differentiated synovial sarcoma of the kidney. Common for all these three cases is the hemangiopericytoma-like histology and a very aggressive clinical behavior. These circumstances accentuate the impact of SS18/SSX analysis in diagnosis of renal hemangiopericytoma-like tumors.
authors.affiliation: Department of Surgery, Cancer Center Karolinska, Karolinska Hospital, Stockholm, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Törnkvist
authors.forename: Johan
authors.initials: J
authors.lastname: Wejde
authors.forename: Jan
authors.initials: J
authors.lastname: Ahlén
authors.forename: Bertha
authors.initials: B
authors.lastname: Brodin
authors.forename: Olle
authors.initials: O
authors.lastname: Larsson
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006393:Hemangiopericytoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007120:Immunochemistry; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009363:Neoplasm Proteins / Q000235:genetics*; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins / Q000235:genetics*; D013584:Sarcoma, Synovial / Q000175:diagnosis* / Q000473:pathology
chemical_list: D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; D011506:Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; C093961:SS18 protein, human; C116512:SYT-SSX fusion protein; C093962:synovial sarcoma X breakpoint proteins