Fine needle aspiration biopsy of monophasic spindle synovial sarcoma of lung with fluorescence in situ hybridization identification of t(x;18) translocation: a case report.

BACKGROUND

Primary monophasic spindle synovial sarcoma can occur in areas with no apparent relation to synovial structures. The diagnosis can be challenging because of the ability to mimic other spindle cell neoplasms. Within the lung, these neoplasms are rare and cytologic descriptions are limited.

CASE

A 58-year-old woman was diagnosed with colonic adenocarcinoma; chest computed tomography (CT) revealed a 5-cm solitary pulmonary mass, and CT-guided fine needle aspiration was performed. Aspirate smears were cellular, with large, loosely cohesive complex tissue fragments that showed dense spindled cells with numerous single stripped spindle cells. Spindle cells were bland and monomorphic, with minimal cellular variation. There was no anaplasia or specific mesenchymal differentiation. Immunohistochemical stains on the cell block were positive for vimentin and bcl-2. A diagnosis of spindle cell neoplasm was rendered; it was believed to be a second neoplasm unrelated to the colonic adenocarcinoma. The main diagnostic consideration was synovial sarcoma. On resection, the neoplasm demonstrated t(x:1 8) chromosomal translocation by fluorescence in situ hybridization.

CONCLUSION

In a spindled cell neoplasm arising as a single peripheral pulmonary nodule, monophacir spindle synorvial sarcoma should be considered in the differential diagnosis; detection of the t(x;18) chromosomal translocation can confirm the diagnosis.