Renal Perivascular Epithelioid Cell Tumor with Lymph Nodes Metastasis: A Case Report and Literature Review

Abstract Background: Perivascular epithelioid cell tumor (PEComa) is mesenchymal tumor that originated from perivascular epithelioid cells. Angiomyolipoma (AML) is a common benign PEComa, composed of blood vessels, smooth muscle and mature adipose tissue. Epithelioid angiomyolipoma (EAML) is a rare subtype of AML that has the potential to be malignant. Case presentation: The patient was a 42-year-old woman admitted to the hospital for her left low back swelling. The computed tomography angiography (CTA) revealed a 6.3*5.5*6.7cm cystic-solid tumor in the intermediate kidney. Then we performed a left nephrectomy. Postoperative pathology showed that the tumor was angiomyolipoma (PEComa) with necrotic formation and was 6cm*6cm*5.5cm in size. Additionally, lymph nodes involved (4/17) were observed in the left renal hilum. Immunohistochemistry staining indicated that tumor cells focally expressed MelanA and HMB45. No evidence of disease progression at the six-month follow-up after surgery. Conclusions: Lymph nodes involvement in renal PEComa was rare and was regarded as a type of metastasis. Lymph nodes metastasis might indicate a poor prognosis.