Monophasic synovial sarcoma: A cytologic spectrum

Abstract

Synovial sarcoma (SS) is a high-grade sarcoma that can be diagnosed in cytology with certainty only when it presents with a biphasic pattern. Monophasic SS (MSS), however, is a diagnostic consideration when a uniform spindle cell population is present. The purpose of this study was to evaluate a series of cytologic cases of MSS and its cytologic presentation. Twenty-one FNAs of histologically confirmed MSS were reviewed. Specimens consisted of tissue fragments and single cells containing scant granular cytoplasm, medium-sized nuclei, and coarse chromatin. A monotonous spindle pattern with comma-shaped nuclei was present in 5 cases. Sixteen cases contained oval and spindled nuclei. Eight of these specimens contained round nuclei, and 5 of these cases showed prominent nucleoli and cohesive clusters, reminiscent of biphasic SS. We conclude that a spectrum of cytologic findings can be seen in MSS, including a secondary population of cells with morphology usually typical of biphasic SS.

Synovial sarcoma: Diagnosis on fine‐needle aspiration by morphology and molecular analysis

“…The cytology of monophasic SS was described by Ewing et al in 17 cases, 4 of which had molecular genetic analyses on the surgical specimen. 17 Our study is a combined analyses of RT-PCR-confirmed and immunohistochemically confirmed cases of SS with both biphasic and monophasic variants. The morphological features highlighted in our study are in concert with the previous studies quoted.…”

“…The morphological features highlighted in our study are in concert with the previous studies quoted. [13][14][15][16][17] The cell yield is usually good and, hence, smears are very cellular. The architectural feature usually evident at low magnification is the prominent pericapillary arrangement, which has been highlighted previously.…”

“…16,17 In the present study, we describe a detailed analysis of the FNA cytology of 16 cases of SS. In 6 of these cases, RT-PCR carried out on the sample obtained by FNA demonstrated the SYT-SSX fusion transcript, which was further confirmed by DNA sequencing.…”

Malignant small round cell tumors

“…Ewing et al . [56] have elaborated on the cytological features of the monophasic variant of synovial sarcoma wherein tissue fragments and single cells containing scant granular cytoplasm, medium-sized nuclei, and coarse chromatin were seen. A monotonous spindle pattern with comma-shaped or oval and spindled or round nuclei were also seen.…”

Synovial Sarcoma of the Heart

“…24 The majority of monophasic SSs are spindle cell neoplasms and cytomorphologically similar to the spindle cells of biphasic SS, consisting of ovoid or comma-shaped nuclei. 23,25,26 In both histologic types of SS, capillaries are admixed with lesional cells. 22,24 The tumor cells of SS on cytologic preparations, particularly the more commonly encountered monophasic type, are often impossible to distinguish from other spindle cell neoplasms.…”