Leiomyosarcomas are rare malignant
tumors of the
kidney. They may arise from the renal
capsule,
renal vein, renal pelvic musculature or renal parenchyma.
Renal pelvis is an uncommon site of occurrence, with around 10 cases reported in the
literature so far. Here we present a 60-year-old
male who presented with increased urinary frequency,
lower limb weakness,
anorexia and
weight loss. Imaging showed a right renal mass. A
renal cell carcinoma was suspected clinically. A right
nephrectomy was performed, which showed a large circumscribed mass in the hilar region.
Histology revealed a
tumor mass arising from the
renal pelvis. The
tumor was composed of spindle
cells arranged in fascicles.
Immunohistochemistry showed
tumor cells to be positive for
smooth muscle actin (SMA) and
desmin (Des) and negative for
cytokeratin (CK), HMB 45, CD117 (C-kit), and CD34. That confirmed the
diagnosis of
leiomyosarcoma.