World Health Organization Classification of Tumours Pathology and ...

ABCFig. 1.47 A t(X:1) RCC. Note tubular and papillary architecture. B t(X:17) renal carcinoma. Note alveolar growth pattern and clear cells. C t(X:1) RCC. Note compactnested architecture. D t(X:1) RCC. Note papillary architecture with foam cells.DFig. 1.48 Xp 11.2-translocation renal carcinoma.Note strong nuclear labeling of the tumour cells.TFE3 protein expression.Fig. 1.49 Xp11 translocation carcinomas. Partialkaryotypes showing t(X;1)(p11.2;q21) in a renaltumour from a male (courtesy of Dr. Suresh C.Jhanwar) and a t(X;17)(p11.2;q25.3) in a renaltumour from a female. The positions of the breakpointsare indicated by arrows (standard G-banding).Reprinted and adapted with permission fromP. Argani et al. {109}.carcinomas and the soft tissue ASPScontain identical ASPL-TFE3 fusion transcripts,the t(X;17) translocation is consistentlybalanced (reciprocal) in the formerbut usually unbalanced in the latter(i.e. the derivative X chromosome is notseen in ASPS) {109}.Prognosis and predictive factorsVery little is known about the clinicalbehaviour of these carcinomas. While theASPL-TFE3 renal carcinomas usuallypresent at advanced stage, their clinicalcourse thus far appears to be indolent.38 Tumours of the kidney