The bizarre mixture of elements may lead to confusion with a malignant. Histology of angiomyolipoma. This is a rare, usually benign neoplasm of the juxtaglomerular cells of the kidney. Clinically, they occur mainly in young people, all of whom present with hypertension. Grossly, the tumors are small, usually less than 3 cm in diameter, well circumscribed and located in the cortex.
Histologic appearances are variable.
The tumor varies in size from a small to very large mass that bulges from the kidney. It is hard in consistency and cut surface is white and whorled. The tumor is composed of spindle cells and the margins are irregular with bands of tumor cells interdigitating with adjacent parenchyma. Mitoses are common but are normal as in other tissues of the rapidly growing infant. The tumor is entirely benign.