Wilms Tumor in an Adult

A 43-year-old woman was admitted to the hospital with left flank pain. The physical examination revealed a left abdominal mass. Laboratory test results identified normochromic- normocytic anemia (hematocrit, 33%; hemoglobin, 10.8 g/dL; and mean corpuscular volume, 88 fL) and microscopic hematuria (10 red blood cells per high-power field). Ultrasonography and a CT scan of the abdomen demonstrated a large, solid tumor in the left kidney. The angiogram depicted a hypovascular tumor. A radical nephrectomy was performed via the transabdominal approach; pathologic examination of the resected mass confirmed Wilms tumor. Wilms tumor, or nephroblastoma, is the most common solid renal tumor that occurs in children; it is rarely seen in adults. The neoplasm develops from remnants of the primitive metanephric blastema of the immature kidney. Alterations in a region on the short arm of chromosome 11 (11p13) have been implicated in the tumor’s development. Surgery and chemotherapy with or without radiotherapy are options; the choice depends on tumor stage and histologic type. Despite its rare occurrence in adults, Wilms tumor needs to be included in the differential diagnosis of all renal masses. This patient’s neoplasm was a stage 2 malignancy— tumor extends beyond the kidney and is completely excised with no residual tumor at or beyond the margins of the excision—according to the National Wilms Tumor Study classification.¹ Adjuvant chemotherapy with vincristine- actinomycin D was given. The patient remains free of disease 45 months after the surgery.