Rapidly Progressing Malignant Epithelioid Renal Angiomyolipoma: A Case Report.

Typical angiomyolipoma (AML) is a benign neoplasm, which consists of a mixture of smooth muscle, fat, abnormal blood vessels, and perivascular epithelioid cells, the latter of which have been described to be present in varying proportions. Recent reports have described renal masses comprised almost entirely of perivascular epithelioid cells and have designated them as “monotypic epithelioid angiomyolipomas (EAMLs)” or “renal epithelioid oxyphilic neoplasms”, which are potentially malignant. It has also been reported EAML sometimes exhibits aggressive growth, rupture, metastasis, or local recurrence. Here, we report a case of rapidly progressing EAML.