Clinical Features Of Renal Epithelioid Angiomyofipoma

Objective: Renal epithelioid angiomyolipoma is a rare subtype of renal angiomyolipoma,which is rare in clinical practice.Renal epithelioid angiomyolipoma is potentially malignant,and a few patients may have distant metastases.At present,the biological behavior of renal epithelioid angiomyolipoma is still a challenging problem.We explored and analyzed the clinical characteristics and biological behavior of renal epithelioid angiomyolipoma to improve the clinical doctors understanding of this disease.Methods: The clinical data of 10 patients with renal epithelioid angiomyolipoma admitted to general hospital of tianjin medical university from June 2012 to November 2018 were analyzed,retrospectively.Among the 10 patients,9 were female and 1 was male.The oldest was 69 years old and the youngest was 17 years old,with an average age of 36±17 years old.All patients underwent preoperative imaging examinations,including color doppler ultrasound,computed tomography or magnetic resonance imaging.None of the 10 patients had a history of tuberous sclerosis and clinical manifestation.The tumors were located in the right kidney in 6 cases and the left kidney in 4 cases.One case was preoperatively considered right renal carcinoma.1 case was considered right kidney carcinoma before surgery;1 case was considered right renal liposarcoma before surgery;1 case was considered the right renal cystic solid mass before surgery: Renal abscesses are more likely;1 case was considered left retroperitoneal malignancy before surgery;Renal angiomyolipoma was considered in 6 cases before surgery,and 5 cases had renal angiomyolipoma with hemorrhage.5 of them were associated with hemorrhage.1 case was performed “radical resection of right kidney”;1 case was performed “right nephrectomy”;1 case was performed “resection of left retroperitoneal mass + partial resection of left kidney”;3 case was performed “open partial nephrectomy”;4 case was performed “Laparoscopic partial nephrectomy”;Hematoxylin-eosin staining(HE staining)and immunohistochemical staining were performed on the surgically resected specimens for pathological diagnosis.Results: According to HE staining and immunohistochemical staining results of postoperative pathological specimens: 8 cases were pathologically diagnosed as renal epithelioid angiomyolipoma;2 cases were pathologically diagnosed as renal angiomyolipoma with partial epithelioid angiomyolipoma.Postoperative follow-up of 10 patients through outpatient and telephone contact,the follow-up time was up to January 2020,a total of 2 patients who were lost to follow-up,the remaining 8 patients were followed up for 13 to 56 months,with an average follow-up time of about 35±14 months.All of the 8 patients who were followed up are currently survived,and no tumor recurrence or distant metastasis was found according to the relevant imaging examinations after the operation.Conclusion: Most renal angiomyolipoma is benign,with a good prognosis and simple diagnosis;Renal epithelioid angiomyolipoma is considered to be a potentially malignant mesenchymal tumor,which is clinically rare,Few patients may develop distant metastases and even die.The early symptoms of renal epithelioid angiomyolipoma is not obvious,and preoperative diagnosis is mainly performed by imaging examination,but it is easy to be confused with other renal tumors such as renal cancer,so need to pay attention for identification.Postoperative pathological HE staining and immunohistochemical staining can further confirm the diagnosis,However,the current histological criteria for the diagnosis of renal epithelioid angiomyolipoma and the criteria for the differentiation of benign and malignant are still uncertain,which may easily cause diagnosis difficulties.The treatment is mainly based on surgical resection,at present,there is no unified understanding of the prognosis,which requires a long-term and close follow-up.