Renal angiomyolipoma (AML) is generally a benign mesenchymal renal tumor with an indolent clinical course. Vascular invasion by AML is uncommon and is more frequently reported in association with tuberous sclerosis complex (TSC). Intracardiac extension of AML, particularly into the right ventricle, is exceptionally rare and can present complex diagnostic and surgical challenges. This case report describes an aggressive presentation of sporadic renal angiomyolipoma with extensive venous extension into the heart in a patient without detectable TSC mutations.
A 36-year-old woman with a prior history of rheumatoid arthritis presented with progressive left upper-quadrant abdominal pain accompanied by nausea and back discomfort. Clinical evaluation prompted cross-sectional imaging that revealed a very large left renal mass. No personal or family history of tuberous sclerosis complex was reported in the source.
Cross-sectional imaging demonstrated a left renal angiomyolipoma measuring 19.5 × 18.0 × 10.5 cm. Imaging also showed a contiguous tumor thrombus originating from the left renal vein and extending through the inferior vena cava (IVC) into the right atrium. The thrombus was noted to intermittently prolapse across the tricuspid valve into the right ventricle. Transthoracic echocardiography confirmed a mobile intracardiac mass but did not show valvular obstruction.
These imaging findings documented extensive vascular and intracardiac involvement despite the absence of clinical or genetic evidence of TSC in this patient.
Genetic testing for mutations in TSC1 and TSC2 returned negative results, consistent with a sporadic rather than TSC-associated angiomyolipoma. The patient underwent surgical resection, and final histopathology confirmed complete excision with negative surgical margins. Pathology also reported an absence of epithelioid features.
The combination of negative TSC1/TSC2 testing and lack of epithelioid histology supports the diagnosis of a sporadic AML that nevertheless demonstrated unusually aggressive intravascular and intracardiac behavior.
Given the tumor size and its continuous extension into the venous system and right heart chambers, a coordinated multidisciplinary operative strategy was employed. The patient underwent an en bloc left radical nephrectomy with complete venous thrombectomy and reconstruction of the inferior vena cava. The operation required collaboration across specialties to address both the renal primary and the intracaval/intracardiac thrombus, and to ensure complete resection with vascular repair.
Final operative and pathologic assessment confirmed the success of the multidisciplinary approach: the tumor and thrombus were completely excised, margins were negative, and there were no epithelioid features identified on histology.
This case highlights several important clinical points derived from the report. First, although AMLs are typically benign and indolent, they can in rare instances demonstrate significant vascular extension, including propagation into the IVC and right heart chambers. Second, aggressive vascular invasion may occur in the absence of TSC-associated mutations and without epithelioid histologic features, challenging conventional associations between genetic background or histology and tumor behavior.
Comprehensive imaging — including cross-sectional studies and echocardiography — was essential to delineate the extent of disease and to plan the operative approach. The presence of a mobile intracardiac component that intermittently prolapsed across the tricuspid valve raised specific surgical considerations addressed by the multidisciplinary team.
Surgical management in this setting aimed for en bloc resection of the primary renal tumor together with complete venous thrombectomy and vascular reconstruction. The successful outcome in this patient supports the feasibility of aggressive surgical management for selected cases of AML with extensive venous extension when undertaken by a coordinated team.
Finally, the authors emphasize that because such tumors can behave unpredictably, close long-term radiographic surveillance is necessary even for lesions classified as benign, to detect potential progression or recurrence.
This report documents an exceptionally rare presentation of a sporadic renal angiomyolipoma with extensive intracaval and intracardiac extension into the right atrium and right ventricle. Key conclusions from the case include:
Significant vascular and cardiac involvement can occur in sporadic AML despite negative TSC1/TSC2 testing and absence of epithelioid histology.
Early recognition and comprehensive imaging are critical for accurate assessment of tumor extent.
Individualized operative planning and a multidisciplinary surgical approach enabled complete resection with negative margins and vascular reconstruction.
Given the potential for aggressive progression in otherwise benign tumors, long-term radiographic surveillance is recommended.
Details such as postoperative course duration, perioperative complications, or specific long-term surveillance protocol were not reported in the source and therefore are not included here.