[Clinical diagnosis and treatment of renal angiomyolipoma with inferior vena cava tumor thrombus].

Objective: To summarize the clinical characteristics of patients with renal angiomyolipoma (RAML) combined with inferior vena cava (IVC) tumor thrombus, and to explore the feasibility of partial nephrectomy and thrombectomy in this series of patients.

Methods: The clinical data of patients diagnosed with RAML combined with IVC tumor thrombus in the Department of Urology of the Peking University Third Hospital from April 2014 to March 2023 were retrospectively analyzed, and demographic and perioperative data of RAML patients with IVC tumor thrombus were recorded and collected from Electronic Medical Record System, including age, gender, surgical methods, and follow-up time, etc. The clinical characteristics between classic angiomyolipoma (CAML) patients with IVC tumor thrombus and epithelioid angiomyolipoma (EAML) patients with IVC tumor thrombus were compared to determine the clinical characteristics of these patients.

Results: A total of 11 patients were included in this study, including 7 patients with CAML with IVC tumor thrombus and 4 patients with EAML with IVC tumor thrombus. There were 9 females (9/11, 81.8%) and 2 males (2/11, 18.2%), with an average age of (44.0±17.1) years. 9 patients (9/11, 81.8%) experienced clinical symptoms, including local symptoms including abdominal pain, hematuria, abdominal masses, and systemic symptoms including weight loss and fever; 2 patients (2/11, 18.2%) with RAML and IVC tumor thrombus did not show clinical symptoms, which were discovered by physical examination. Among the 11 patients, 10 underwent radical nephrectomy with thrombectomy, of whom, 3 underwent open surgery (3/10, 30.0%), 2 underwent laparoscopic surgery (2/10, 20.0%), and 5 underwent robot-assisted laparoscopic surgery (5/10, 50.0%). In addition, 1 patient underwent open partial nephrectomy and thrombectomy. The patients with EAML combined with IVC tumor thrombus had a higher proportion of systemic clinical symptoms (100% vs. 0%, P=0.003), more intraoperative bleeding [400 (240, 3 050) mL vs. 50 (50, 300) mL, P =0.036], and a higher proportion of tumor necrosis (75% vs. 0%, P=0.024) compared to the patients with CAML combined with IVC tumor thrombus. However, there was no statistically significant difference in operation time [(415.8±201.2) min vs. (226.0±87.3) min, P=0.053] between the two groups.

Conclusion: Compared with the patients with CAML and IVC tumor thrombus, the patients with EAML and IVC tumor thrombus had a higher rate of systemic symptoms and tumor necrosis. In addition, in the selected patients with CAML with IVC tumor thrombus, partial nephrectomy and tumor thrombectomy could be performed to better preserve renal function.