Renal angiomyolipoma with extension into renal vein

Renal angiomyolipoma with renal vein extension

Renal angiomyolipomas are uncommon benign tumors containing fatty tissue. Only a few cases of infiltrating angiomyolipomas have been reported. We aimed to describe a case of a 65-year-old woman presenting a peripheral angiomyolipoma of the left kidney with CT evidence of involvement of the renal vein. The lesion has been found incidentally during abdominal CT for an unrelated reason. The patient underwent surgical treatment considering the vascular extension of the lesion and the risk of thromboembolic complications. The pathological analysis confirmed the diagnosis of renal AML in the upper pole of the left kidney invading the renal vein without malignancy.No post-operative complications and the evolution was favorable.

Renal oncocytoma with and without intravascular extension into the branches of renal vein have the same morphological, immunohistochemical and genetic features

We attempted to investigate the clinicopathological correlation of renal oncocytoma (RO) with renal vein extension. We identified seven ROs with extension into the branches of renal vein. The age of seven patients ranged from 61 to 82 years. Five cases were identified; incidentally, two patients had gross hematuria. After surgery, all patients were alive and free of tumors with follow-up of 1 to 5 years (mean=3.6). Oncocytomas measured from 2.2 to 7.5 cm. Renal vein extension was grossly suspected in 5/7 cases and histologically confirmed in all seven cases. Tumor cells were positive for cytokeratins, mitochondrial antigen, epithelial membrane antigen, and parvalbumin; 5/7 tumors were focally positive for cluster of differentiation 117. Ultrastructurally, the cytoplasm was packed by mitochondria. Molecular genetic analysis did not detect abnormal numbers of chromosomes 1, 2, 6, 7, 10, 17, and XY by fluorescence in situ hybridization, loss of heterozygosity on 3p, and mutation of Von Hippel-Lindau gene in all cases. Array comparative genomic hybridization analysis of two cases did not show any major genetic changes. Conclusions are: (1) renal oncocytomas may have intravascular extension to the branches of the renal vein; (2) renal oncocytomas with intravascular extension to the branches of the renal vein have the same morphological, immunohistochemical, and cytogenetic findings as have their counterparts without evidence of intravascular invasion; (3) the absence of metastases suggests an overall benign behavior of this tumor, but this has to be substantiated by further studies with a long-term follow-up; (4) in a renal tumor with granular cytoplasm showing renal vein extension, it is necessary to carefully exclude renal cell carcinomas (RCC) such as chromophobe RCC, oncocytic variant of papillary RCC, and granular variant of clear cell RCC.

Angiomiolipoma renale: Nostra esperienza in 14 casi sottoposti a terapia chirurgica

Renal angiomyolipoma (AML) is an uncommon hamartomatous benign tumour and may present in an isolated form or associated with tuberous sclerosis (Bourneville's disease). Since there is no specific symptomatology when dimensions are small or medium, discovery is often accidental and the tumour may sometimes grow to a considerable size. In the symptomatic forms or larger tumours, surgery may be indicated due to the risk of retroperitoneal hemorrhage, both spontaneous and secondary to lumbar trauma, however slight. As the tumour is benign, kidney-sparing surgery should be as conservative as possible. For this purpose, ultrasound and CT scan are considered essential for a differential diagnosis between AML and parenchymal renal masses. In our experience with 14 cases (12 women and 2 men; minimum age 31 years, maximum 62 years) of monolateral renal AML (10 right kidney AML and 4 left kidney AML) in patients not suffering from tuberous sclerosis, treated surgically between August 1988 and February 1997, the pre-operative ultrasound and CT scan gave a correct diagnosis in 7 cases, a suggestion of renal carcinoma in 5 cases while leaving doubts in 2 cases. The two methods of investigation therefore proved not to be error-free. Following instrumental diagnosis, 12 patients underwent enucleoresection of the tumour while the remaining two underwent extensive nephrectomy. The presence of hemorrhagic areas with AML was considered to be the frequent cause of pre-operative diagnostic error.