Primary Leiomyosarcoma of the Kidney

Primary leiomyosarcoma of the kidney is a rare tumor with an aggressive behaviour. A 55-year-old woman presented with a left sided abdominal mass in our outpatient department. Radiologic investigations revealed the mass to be renal in origin with colonic adhesions for which radical nephrectomy and hemicolectomy were done. The tumor completely appeared to replace the left kidney and had a whorled character focally on cut section. Microscopically, spindle cells having malignant features with cigar shaped nuclei were seen. The smooth muscle origin of the cells was confirmed by immunohistochemical positivity for smooth muscle actin. Sarcomatoid variant of the renal cell carcinoma was ruled out as the tumor was negative for cytokeratin. Tumors with spindle cell morphology in the kidney should not always be taken for a sarcomatoid variant of renal cell carcinoma and should be investigated thoroughly. 1. Introduction Renal sarcomas are rare tumors. They constitute only 1%-2% of malignant renal tumors in the adulthood [1]. Though leiomyosarcoma is the most common histologic type of the renal sarcoma (50%–60%), the information available about renal leiomyosarcomas is limited. We report a case of renal leiomyosarcoma with colonic adhesions and also review the relevant literature. 2. Case Report A 55-year-old woman presented with large palpable mass on the left side of the abdomen with dull aching pain in the flank and abdomen. Surprisingly, she had noticed the mass one month earlier on turning or bending forward. She had no haematuria, fever, or history of bowel disturbances. Previous medical history was not significant. On examination, vitals were within normal limits. Physical examination revealed a firm multinodular, mildly tender mass in the left hypochondrium extending up to left iliac, left lumbar, and umbilical region. The mass moved with respiration. No other organomegaly was present. Laboratory investigations revealed normocytic hypochromic anaemia with a raised ESR. Serum chemistry levels were normal. Urinalysis showed 2–5 polymorphonuclear cells per high power field without any evidence of microscopic haematuria. Abdominal ultrasonography showed a large heterogenous mass originating from lower half of left kidney and occupying more than three fourths of it. A portion of uninvolved left upper pole showed hydronephrotic changes. Computed tomographic scan revealed a large left renal mass without any vascular or hepatic metastasis. There was no calcification in the lesion. A provisional diagnosis of renal cell carcinoma was made. Left radical nephrectomy