Figure 2
Hematoxylin and eosin (H&E) stain,
(x100): Left: tumor composed of spindle cells arranged in interlacing
bundles and fascicles Right: tumor cells with oval to elongated nuclei
having blunted ends
Immunohistochemistry was done and tumor cells showed diffuse positivity
with smooth muscle actin (SMA) and focal positivity for desmin
(Figure 3). Cytokeratin was negative. A
final diagnosis of renal leiomyosarcoma, high grade (Grade 2) using the
French Federation of Cancer Centers System was
made. The renal leiomyosarcoma was
staged as pT3bN0M0 , meaning the tumor had extended into the
renal vein without evidence of lymph node involvement or distant
metastasis at the time of diagnosis.