Cytologic features on needle aspiration of Wilms' tumor in an adult. A case report.
A needle aspiration specimen from a left kidney mass in a 28-year-old woman was submitted for cytologic evaluation. Malignant cells were found, and the cytologic appearance was suggestive of a poorly differentiated sarcoma, with the possibility that it was a nephroblastoma. Important cytologic features of the needle aspiration specimen included round or oval blastomatous cells mixed with spindle or elongated sarcomatous cells, rare tubulelike formations of cells that appeared epithelial and a pronounced tumor diathesis. Histologic study of the nephrectomy specimen showed a Wilms' tumor, with anaplastic blastomatous and undifferentiated sarcomatous elements.