[Renal epithelioid angiomyolipoma].

Area of Science:

• Oncology
• Pathology
• Urology

Background:

• Renal epithelioid angiomyolipomas (ReAML) are rare kidney tumors, comprising 8% of operated angiomyolipomas (AML).
• These tumors are histologically defined by an epithelioid cell component alongside typical AML cells and are classified as perivascular epithelioid cell (PEComa) tumors.
• ReAML can be benign, potentially aggressive, or malignant, with most malignant PEComas being ReAML, presenting as sporadic or Tuberous Sclerosis Complex (TSC)-associated entities.

Purpose of the Study:

• To describe the characteristics, diagnosis, and treatment of renal epithelioid angiomyolipomas (ReAML).
• To differentiate ReAML from renal cell carcinoma (RCC) and discuss management strategies based on tumor behavior.

Main Methods:

• Histological examination for diagnosis, identifying epithelioid cell components.
• Radiological assessment (CT-scan) noting fat-poor characteristics.
• Clinical evaluation of tumor presentation, size, and association with TSC.

Main Results:

• ReAML are unique, localized kidney tumors, often discovered incidentally or via complications like hemorrhage.
• Fat-poor appearance on CT-scan can lead to misdiagnosis as renal cell carcinoma (RCC).
• Approximately one-third of ReAML are malignant, with potential for fatal locoregional, nodal, or metastatic spread.

Conclusions:

• ReAML diagnosis is histological, requiring differentiation from RCC.
• Treatment is multimodal, ranging from partial nephrectomy or follow-up for benign cases to radical nephrectomy with adjuvant therapy (doxorubicin, rapamycin) for aggressive or malignant forms.