Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

Fig. 1.121 Synovial sarcoma of the kidney.
Immunoexpression of CD99 in the synovial sarcoma
of the kidney.
ing cells of the cysts are consistently
highlighted by these markers {112,1316}.
Fig. 1.122 Synovial sarcoma of the kidney. SYT-SSX
fusion transcripts demonstrated by RT-PCR. M,
molecular size marker;1, positive control; 2,negative
control; 3 and 4, synovial sarcomas.
Genetics
Synovial sarcoma is cytogenetically characterized
by the translocation t(X;18)
(p11.2/q11.2) generating a fusion between
the SYT gene on chromosome 18 and one
member of the SSX family gene(SSX1;SS
X2;SSX4) on chromosome X.
Molecularly confirmed primary renal synovial
sarcomas have demonstrated the
characteristic SYT-SSX gene fusion {112,
1316,1379}. In contrast to soft tissue synovial
sarcoma where the SYT-SSX1 gene
fusion is more common than the alternative
SYT-SSX2 form {1422}, the majority
of renal synovial sarcomas have so far
demonstrated the SYT-SSX2 gene fusion
{112,1316,1379}. In soft tissue synovial
sarcomas, the SYT-SSX2 form of the
gene fusion is strongly correlated with
monophasic histology {1422}; this tendency
is also consistent with the predominance
of monophasic spindled morphology
of these tumours in the kidney
and the rarity of biphasic histology.
Prognosis and predictive factors
Prognostic data are limited, some have
responded to chemotherapy, however
recurrence is common.
80 Tumours of the kidney