Primary Pulmonary Sarcoma With Morphologic Features of Monophasic Synovial Sarcoma and Chromosome Translocation t(X; 18)

Abstract

The authors report an unusual spindle cell sarcoma that arose in the lung of a 12-year-old girl. This tumor had histologic, immunophenotypic, and ultrastructural features consistent with monophasic fibrous synovial sarcoma. These features included a growth pattern of densely packed spindle cells in irregularly intersecting, broad fascicles, diffuse vimentin immunoreactivity, and focal expression of epithelial membrane antigen and S100 protein. This diagnosis was further supported by cytogenetic studies showing the specific t(X; 18) chromosomal translocation associated with synovial sarcoma. This balanced translocation appears to be an essentially universal characteristic of these sarcomas, regardless of histologic subtype or site of origin. The constellation of morphologic and cytogenetic findings in this case firmly establishes synovial sarcoma as a subtype of pulmonary spindle cell sarcomas. The distinctive features of these neoplasms allow them to be distinguished from a variety of primary and metastatic malignancies in the lung.

Pulmonary Carcinomas With Pleomorphic, Sarcomatoid, or Sarcomatous Elements

“…18,23,26,32,34,50,68,79 A generous sampling (at least one section per centimeter of tumor diameter) and the use of ancillary techniques, such as electron microscopy and immunohistochemistry, can be necessary to disclose the epithelial nature of the tumor.…”

Detection ofSYT-SSXFusion Transcript in Synovial Sarcoma Using Archival Cytologic Specimens

“…Eleven cytologic and 12 histologic specimens stored for 0.1 to 20 years were selected from 9 patients. The SYT-SSX transcript was identified in 10 Synovial sarcoma (SS) accounts for approximately 10% of soft-tissue sarcomas and occurs mainly in adolescents and young adults.' Occasionally the tumors manifest in areas where there are no obvious synovial structures, such as the head and neck region or the thoracic wall, but they usually are more associated with extremities.…”

“…3 The detection of the specific translocation of SS has been used as an ancillary method for establishing the definite diagnosis. So far, cytogenetics, 10,11 fluorescence in situ hybridization (FISH), 12 and reverse transcription-polymerase chain reaction (RT-PCR) 613 have been performed using fresh or frozen materials. FISH has been applied to paraffin tissues.…”

Sarcomatoid Carcinomas of the Lung: A Clinicopathologic Review

“…1 ' 8 ' 114,115 Finally, SCs arising at the extreme periphery of the lung may involve the pleura and cause confusion with sarcomatoid malignant mesothelioma. 116 The clinical and histologic attributes of these neoplasms have been well covered in other public a t i o n s .…”

“…However, we urge caution because synovial sarcoma and sarcomatoid mesothelioma may be virtually identical to SC as s e e n w i t h the e l e c t r o n m i c r o s c o p e or in i m m u n o p h e n o t y p i c e v a l u a t i o n s . The m a r k e d propensity for synovial sarcoma to affect children, a d o l e s c e n t s , a n d y o u n g a d u l t s a n d its typical t(X;18) cytogenetic aberration 114 ' 115 (not seen in carcinomas) are crucial points in its distinction from SC of the upper airway, and nuances of histologic appearance and radiographic characteristics also are valuable in this differential diagnosis. Similarly, roentgenologic findings are more helpful than morphologic observations in making the distinction between SC and spindle cell or biphasic mesothelioma.…”