Identification of a ring chromosome with spectral karyotyping in a pleural synovial sarcoma

Pediatric Primary Pleural Synovial Sarcoma: A Unique Case Report with Brief Review of Literature

Synovial sarcoma (SS) primary to the pleura is an extremely rare tumor. So far, only nine cases have been reported in pediatric patients. However, none of these patients was found to have a conglomeration of tumors. Here, we report a case of 16-year-old female with monophasic SS and synchronous occurrence of left paraspinal ganglioneuroma and a right paraovarian cystadenoma. A next-generation sequencing genetic panel revealed a novel variant of unknown significance in the MET gene. The occurrence of multiple different tumors in a young patient with a novel genetic variant in a known oncogene (MET) may suggest a possibility of a hitherto unknown cancer predisposition syndrome. We also present a brief review of primary pleural SS reported in pediatric patients.

Characterization of giant marker and ring chromosomes in a pleomorphic leiomyosarcoma of soft tissue by spectral karyotyping

Pleomorphic leiomyosarcoma of soft tissue is relatively rare and its cytogenetic and molecular genetic data are scarce. We present a case of pleomorphic leiomyosarcoma arising in the left thigh of a 60-year-old man. Fluorine-18-deoxyglucose positron emission tomography imaging showed a homogenously high uptake within the mass in the proximal left thigh (maximum standardized uptake value, 20.9). Following a core needle biopsy, wide resection of the tumor was performed. Histologically, the tumor was composed of a mixture of spindle cells, polygonal cells and bizarre giant cells forming interlacing bundles and a storiform pattern. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin and desmin. The MIB-1 labeling index was 19.7% in the highest spot. Cytogenetic analysis exhibited a complex karyotype with several numerical and structural alterations, including giant marker and ring chromosomes. Spectral karyotyping demonstrated that giant marker and ring chromosomes were composed of material from the X chromosome. Metaphase-based comparative genomic hybridization analysis showed high-level amplifications of 1q21-q25 and 12q13-q21 and gains of 1p31-p32, 10p11-p13, 17p11 and 19p13. The patient received postoperative adjuvant radiotherapy and doxorubicin-based chemotherapy. No local recurrence or distant metastasis was detected during a follow-up period of 19 months. The clinicopathological, cytogenetic and molecular genetic features of pleomorphic soft tissue leiomyosarcoma are discussed.