Aspiration biopsy cytology of renal angiomyolipoma.

The aspiration cytology of a renal angiomyolipoma is reported. Single mature fat cells, clusters of renal tubular epithelial cells and single as well as groups of smooth muscle cells were seen. The smooth muscle cells were pleomorphic, with vacuolated, granular or fibrillar cytoplasm. Their nuclei varied in size and shape and displayed variable chromatin patterns, ranging from finely to coarsely granular. Many nuclei contained prominent nucleoli.