Monophasic synovial sarcoma–a histological entity?

Abstract

Consideration is given to the concept of a histologically identifiable monophasic type of synovial sarcoma. It is accepted that a sarcomatous tumour may be encountered where the spindle cells assume a somewhat epithelioid appearance associated with a reticulin pattern unlike that of most other spindle cell sarcomas. The appearance should alert a hsitopathologist to the possibility of a synovial sarcoma and prompt the examination of multiple additional sections in an attempt to find the pathognomonic biphasic pattern. It is not, however, believed that an entire tumour composed of cells of a single type could be identified with certainty as a synovial sarcoma by light microscopy. The term monophasic synovial sarcoma is worthy of retention, but only as a guide towards the establishment of a definite diagnosis by further sampling of the specimen. Other features suggestive of this diagnosis are discussed.

CO2 Laser in the Treatment of Laryngeal Synovial Sarcoma: A Clinical Case

“…The diagnosis of SS of the head and neck is particularly difficult due to the rare occurrence of the tumor in this region and its resemblance to other tumors occurring more frequently in the head and neck. SSs are histologically divided into two subgroups: biphasic SS, characterized by the admixture of spindle and epithelioid cells, the latter often organized in gland-like structures, and monophasic SS, in which only one cell component, either spindle or, less often, epithelioid, is present 7,[9][10][11][12] . Biphasic SS needs to be distinguished from a carcinoma with partial sarcomatoid differentiation, while monophasic spindle cell SS requires a differential diagnosis with all spindle cells tumors, including hemangiopericytoma, malignant schwannoma, and spindle cell carcinoma.…”

Monophasic synovial sarcoma: a case report and literature review

“…In the large majority of cases, this applies to the spindle cell sarcomatous component, which is easily misdiagnosed as fibro sarcoma, hemangiopericytoma or some other spindle cell neoplasm by the unwary. 9,10 Histopathological examination of the excised mass from our patient revealed cellular lesion composed of sheets and fascicles of spindle cells with indistinct cytoplasm, irregular nuclear membrane, mild pleomorphism, open chromatin and prominent nucleoli. Foci of necrosis, haemorrhages were seen but there was no evidence of vascular emboli.…”

Sarcomas-a clinicopathological guide with particular reference to cutaneous manifestation III. Angiosarcoma, malignant haemangiopericytoma, fibrosarcoma and synovial sarcoma

“…15) quite common in the typical biphasic synoviai sarcomas (Roth et al, 1975;Evans, 1980;Schmookler, Enzinger & Brannon, 1982, Varela-Duran & Enzinger, 1982 and (ii) the presence of focal calcification, again not unusual in the typical case (Crocker & Stout, 1959;Cadman et a/., 1965;Varela-Duran & Enzinger, 1982). MacKenzie (1977), however, showed that, by careful exaniination of so-called monophasic tumours, features of a developing biphasic pattern can be identified, especially with the use of a reticulin stain; and if, as a consequence, further sections of the tumour are cut then the typical biphasic pattern v^-ill be revealed. Other authors have similarly felt that a careful search will reveal an epithelioid component, thus verifying the diagnosis (Roth et al, 1975;Schmookler et al, 1982;Varcla-Duran & Enzinger, 1982).…”