We experienced a case of primary pulmonary biphasic synovial sarcoma, which was confirmed by immunohistochemistry and molecular testing of SYT-SSX2 fusion transcripts. The patient was a 61-year-old man who presented with a well-defined mass in the left upper lung field on chest radiography. Left upper lobectomy with lymph node dissection was performed. Histological and immunophenotypic features were consistent with biphasic synovial sarcoma. Reverse transcriptase polymerase chain reaction, performed using RNA extracted from frozen tumor samples for the detection of SYT-SSX fusion gene, amplified a single 331-bp fragment that was characteristic of the SYT-SSX2 fusion transcripts. We report a case of primary pulmonary biphasic synovial sarcoma, which was confirmed by SYT-SSX2 fusion transcripts, and present a brief review of the literature on Korean cases.
Base Sequence ; DNA Primers/genetics ; Humans ; Korea ; Lung Neoplasms/diagnosis/*genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion/*genetics ; Oncogenes ; Sarcoma, Synovial/diagnosis/*genetics

Adolescent ; Child ; Female ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Leg ; Male ; Paraffin Embedding ; Sarcoma, Synovial ; diagnosis ; genetics ; pathology ; Soft Tissue Neoplasms ; diagnosis ; genetics ; pathology ; Translocation, Genetic

OBJECTIVETo establish a method of SYT-SSX fusion gene detection by FISH and to explore its diagnostic value for synovial sarcoma.

METHODSThe presence of SYT-SSX fusion gene was determined by FISH using a tissue microarray containing 62 known synovial sarcomas, 60 non-synovial sarcomas and 133 equivocal synovial sarcomas. FISH results were compared with those of RT-PCR published previously.

RESULTSOverall, 96.9% (247/255) of the cases were successfully analyzed by FISH. The sensitivity of FISH for known synovial sarcomas was 96.7% (58/60), and the specificity for the non-synovial sarcoma was 100% (59/59). Moreover, SYT-SSX gene fusion was detected in 78.1% (100/128) of the equivocal synovial sarcomas. The concordance rate between FISH and RT-PCR was 83.6% (102/122) in those equivocal synovial sarcomas, and overall 79.7% (106/133) of these cases were confirmed as synovial sarcomas either by RT-PCR or by FISH.

CONCLUSIONSThe sensitivity and specificity of FISH detection of SYT-SSX fusion gene are high. FISH and RT-PCR are complementary to each other in the confirmation of synovial sarcomas, particularly those questionable cases.

Biomarkers, Tumor ; analysis ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; methods ; Nucleic Acid Hybridization ; methods ; Oncogene Proteins, Fusion ; genetics ; isolation & purification ; Pathology, Molecular ; methods ; Reverse Transcriptase Polymerase Chain Reaction ; Sarcoma, Synovial ; diagnosis ; genetics ; Soft Tissue Neoplasms ; diagnosis ; genetics

Objective: To investigate the clinicopathological features, immunophenotype, molecular features and differential diagnosis of primary synovial sarcoma of the lung (PSSL). Methods: Twelve cases of PSSL were collected at Henan Provincial People's Hospital, during May 2010 and April 2021, and their clinicopathological parameters were summarized. SS18-SSX, H3K27Me3, and SOX2 were added to the original immunomarkers to evaluate their diagnostic value for PSSL. Results: The age of 12 patients when diagnosed ranged from 32 to 75 years (mean of 50 years). There were 7 males and 5 females, 2 left lung cases and 10 right lung cases. Of the 6 patients who underwent surgical resection, five cases were confined to lung tissue (T1), one case had mediastinal invasion (T3), two cases had regional lymph node metastasis (N1), and none had distal metastasis. Microscopically, 11 cases showed monophasic spindle cell type and one case showed biphasic type composed of mainly epithelial cells consisting of cuboidal to columnar cells with glandular and cribriform structures. It was difficult to make the diagnosis by using the biopsy specimens. Immunohistochemistry (IHC) showed CKpan expression in 8 of 12 cases; EMA expression in 11 of 12 case; TLE1 expression in 8 of 12 cases; S-100 protein expression in two of 12 cases; various expression of bcl-2 and vimentin in 12 cases, but no expression of SOX10 and CD34 in all the cases. The Ki-67 index was 15%-30%. The expression of SS18-SSX fusion antibody was diffusely and strongly positive in all 12 cases. SOX2 was partially or diffusely expressed in 8 of 12 cases, with strong expression in the epithelial component. H3K27Me3 was absent in 3 of 12 cases. SS18 gene translocation was confirmed by fluorescence in situ hybridization (FISH) test in all 12 samples. Six cases underwent surgery and postoperative chemotherapy, while the other six cases had chemotherapy alone. Ten patients were followed up after 9-114 months, with an average of 41 months and a median of 26 months. Five patients survived and five died of the disease within two years. Conclusions: PSSL is rare and has a broad morphological spectrum. IHC and molecular tests are needed for definitive diagnosis. Compared with current commonly used IHC markers, SS18-SSX fusion antibody has better sensitivity to PSSL, which could be used as an alternative for FISH, reverse transcription-polymerase chain reaction or next generation sequencing in the diagnosis of PSSL.
Male ; Female ; Humans ; Adult ; Middle Aged ; Aged ; Biomarkers, Tumor/analysis* ; Sarcoma, Synovial/diagnosis* ; In Situ Hybridization, Fluorescence ; Histones/genetics* ; Proto-Oncogene Proteins/metabolism* ; Oncogene Proteins, Fusion/genetics* ; Repressor Proteins/metabolism* ; Lung/pathology* ; Lung Neoplasms

12E7 Antigen ; Antigens, CD ; metabolism ; Cell Adhesion Molecules ; metabolism ; Diagnosis, Differential ; Fibrosarcoma ; metabolism ; pathology ; Heart Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Humans ; Male ; Mesothelioma ; genetics ; metabolism ; pathology ; Middle Aged ; Mucin-1 ; metabolism ; Oncogene Proteins, Fusion ; metabolism ; Pericardiectomy ; Pericardium ; pathology ; Sarcoma ; metabolism ; pathology ; Sarcoma, Synovial ; genetics ; metabolism ; pathology ; surgery ; Translocation, Genetic ; Vimentin ; metabolism