Wilms Tumor : Fibroblastic stroma

Comments:
The stromal component of Wilms tumor is usually fibroblastic (shown here) or myxoid and may contain heterologous elements such as skeletal muscle, smooth muscle, bone, cartilage, adipose tissue, and neuroglial tissue. Some cases show extensive skeletal muscle differentiation. These cases usually occur in young children (as opposed to infants), are frequently bilateral, and have better prognosis.