Incidental finding of tuberous sclerosis complex in a woman with hematuria: A case report of renal angiomyolipoma and review of the literature

Tuberous sclerosis complex (TSC) is a rare genetic multisystem disorder that was first described by Von Recklinghausen. We describe a case of a female, who initially presented with hematuria and was later found to have multiple manifestations of the disease. The report emphasizes the value of investigations on suspected cases.

Renal Angiomyolipoma: Radiologic Classification and Imaging Features According to the Amount of Fat

OBJECTIVE

The purposes of this article are to introduce the radiologic classifications of renal angiomyolipoma (AML) and the clinical implications, to show the imaging features of each type of AML, and to describe which types of AML should be biopsied.

CONCLUSION

Renal AML can be classified according to amount of fat as fat rich, fat poor, or fat invisible. To detect fat, one needs to thoroughly evaluate the entire AML by controlling the size and shape of the ROI. Fat-invisible AML should be biopsied, and fat-poor AML requires further investigation to determine whether biopsy is necessary to differentiate it from renal cell carcinoma. If differentiation between AML and renal cell carcinoma is not clear with CT and MRI, percutaneous biopsy may be performed.

Aspiration Biopsy in Renal Angiomyolipoma

Ultrasound guided aspiration biopsy of renal mass lesions was performed in 56 patients in whom renal cell carcinoma could not be excluded due to equivocal imaging results. Cytology showed non-malignant mesenchymal cells consistent with angiomyolipoma in 12 patients. In 5 of these patients the diagnosis was ensured by open biopsy. No nephrectomy was performed. In 6 of the 7 patients not operated upon the tumours remained unchanged with no evidence of malignancy during a 3–36 months' follow-up period. Aspiration biopsy is an easy and safe method for diagnosing renal angiomyolipoma in cases where computed tomography is not diagnostic for this disease.

Clinical Risk Management in radiology. Part II: applied examples and concluding remarks

With the aim of providing a clearer understanding of the tools used for evaluating risk in the radiological setting and how they are applied, this second part presents two practical examples. The first is a proactive analysis applied to CT, whereas the second is a reactive analysis performed following a sentinel event triggered by a CT study allocated to the wrong patient in the RIS-PACS system.

The management of renal angiomyolipomas in a patient with tuberous sclerosis

BACKGROUND

A 17-year-old girl, who was diagnosed with tuberous sclerosis in infancy, presented with multiple bilateral renal masses, the largest of which was 6.0 cm in diameter on the left side.

INVESTIGATIONS

History and physical examination, ultrasonography, MRI, CT, magnetic resonance angiography, and measurement of serial creatinine levels.

DIAGNOSIS

Bilateral angiomyolipomas.Management Observation, serial imaging, embolization and infarction.

MR imaging of renal masses: correlation with findings at surgery and pathologic analysis

Magnetic resonance (MR) imaging is useful in the characterization of renal masses. The MR imaging manifestations and pathologic diagnoses of 82 renal masses were reviewed and correlated. The MR imaging appearance of clear cell type renal cell carcinoma varies depending on the presence of cystic components, hemorrhage, and necrosis. Papillary renal cell carcinomas appear as well-encapsulated masses with homogeneous low signal intensity on T2-weighted images and homogeneous low-level enhancement after the intravenous administration of contrast material, or as cystic hemorrhagic masses with peripheral enhancing papillary projections. Transitional cell carcinoma may be seen as an irregular, enhancing filling defect in the pelvicaliceal system or ureter. Lymphomatous masses are usually hypointense relative to the renal cortex on T2-weighted images and enhance minimally on delayed gadolinium-enhanced images. Bulk fat is a distinguishing feature of angiomyolipoma. Oncocytoma has a variable and nonspecific appearance at MR imaging. MR imaging findings may allow the characterization of various renal masses and can provide valuable information for their clinical management.

Tuberous sclerosis complex and renal angiomyolipoma: case report and review of the literature

A 5-year-old boy with a known diagnosis of tuberous sclerosis complex was found to have an enlarging renal mass on routine ultrasound. He was diagnosed with an angiomyolipoma (AML) and scheduled for close observation. Follow-up magnetic resonance imaging demonstrated the AML to be significantly enlarged and hypervascular. Selective arterial embolization of the tumor was performed, which resulted in an appropriate decrease in tumor size. Angiomyolipoma is a known and well-described complication of the tuberous sclerosis complex that is usually found among patients in their adolescent and adult years. The case presented here illustrates the need for early and repeated renal imaging of younger pediatric patients with tuberous sclerosis. Our experience adds to the literature on young pediatric patients requiring embolization for treatment of large renal angiomyolipomas.

Angiomyolipoma in the knee--a case report

Extrarenal angiomyolipoma is an uncommon disease and this may be the first report of angiomyolipoma in the knee, mimicking a malignant sarcoma. A 38-year-old man without tuberous sclerosis presented with a history of increased mass in the knee joint. Computerized tomography and magnetic resonance imaging demonstrated a CS x CS x CR cm subcutaneous tumor in the knee joint. The tumor was widely excised. Histologically, the tumor was, well circumscribed, and composed of smooth muscle, vascular spaces, connective tissue, and mature fat. There were no signs of recurrence at one year and eight months after surgery.

Contemporary diagnosis and management of renal angiomyolipoma

PURPOSE

We present a comprehensive resource that summarizes contemporary advances relevant to the clinical management of renal angiomyolipoma.

MATERIALS AND METHODS

A MEDLINE search was done using the key words angiomyolipoma, hemangioma or lipoma and kidney neoplasm, and therapeutic embolization. References from these articles were reviewed to identify additional relevant source material. We identified 13 series published since 1986 comprising 336 patients as well as 24 reports of therapeutic embolization for angiomyolipoma, comprising 76 patients. To our knowledge we report the largest compilation series to date.

RESULTS

Angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Tuberous sclerosis associated angiomyolipoma tends to be larger, multiple and more likely to cause spontaneous hemorrhage than the sporadic entity. Tumors that hemorrhage tend to be larger. Computerized tomography or magnetic resonance is usually sufficient for diagnosis. Biopsy is rarely useful. Primary indications for intervention include symptoms such as pain or bleeding or suspicion of malignancy. Prophylactic intervention is justifiable for large tumors, in females of childbearing age or in patients in whom followup or access to emergency care may be inadequate. Recent advances that have affected management include improved understanding of tuberous sclerosis complex and angiomyolipoma genetics, the identification of molecular markers that facilitate histopathological diagnosis, and the refinement of embolization and partial nephrectomy techniques.

CONCLUSIONS

Although some cases of angiomyolipoma may require complete nephrectomy, most can be managed by conservative nephron sparing approaches. Ongoing research into the molecular biology and clinical behavior of angiomyolipoma may improve our ability to manage these lesions.

Renal manifestations of tuberous sclerosis complex

Patients with tuberous sclerosis complex (TSC) are at increased risk of renal disease, predominantly angiomyolipomas and renal cysts. We retrospectively reviewed clinical data of 71 patients diagnosed with TSC. Progression of renal lesions was noted. TSC patients with renal lesions were compared with TSC patients without renal disease. Fifteen of 38 patients had renal abnormalities by imaging at presentation. Six of 9 with initially normal kidneys subsequently developed new lesions. Although not of statistical significance, there was a trend toward increased retinal hamartomas, cardiac rhabdomyomas, and skin lesions in those patients who also had renal abnormalities. Renal disease should be considered and sought in all patients with TSC, both at initial presentation and subsequently, since renal disease is a very significant cause of morbidity and mortality.

A case of angiomyolipoma diagnosed by thin slice non-enhanced CT and needle biopsy

We report a case of a 52-year-old female with two intrarenal tumors in the left kidney and a contralateral non-functioning kidney. Two renal cell carcinomas were suspected on 10mm and 5mm thick slices of computed tomography (CT), while angiography could not exclude a diagnosis of angiomyolipoma. Thin section (2 mm thick) non-enhanced CT detected negative attenuation values (indicative of fat) within both tumors, but these values were higher than the value for normal fat tissue. Negative attenuation values within the tumor using non-enhanced thin sections are thought to be essential for a CT diagnosis of angiomyoplipoma, especially when angiomyolipoma is difficult to distinguish from renal cell carcinoma. We performed an ultrasonography-guided needle biopsy of the tumor and pathological examination confirmed the diagnosis of angiomyolipoma, consisting of rich angiomyomatous element and small amount of mature adipose tissue.

Bilateral renal angiomyolipoma

Bilateral renal angiomyolipoma is a rare entity, usually associated with tuberous sclerosis. Five cases of bilateral renal angiomyolipoma, all females, with a mean age of 34.6 years, are reported. All patients had symptoms attributable to lesions only on one side, with flank pain and mass the commonest symptoms encountered. Only one case had clinical evidence of stigmata of tuberous sclerosis. The mean size of the lesions on the symptomatic side was 17 cm, while that on the asymptomatic side was 2 cm. Three patients were diagnosed correctly as having angiomyolipomas preoperatively with the use of ultrasonography and computed tomography (CT); two of these were treated with total nephrectomy and the third with partial nephrectomy. The other two cases were seen before the availability of CT and were only diagnosed intraoperatively. Both patients were treated with total nephrectomy. The lesions on the asymptomatic side were kept on close surveillance. Two patients developed an increase in the size of the lesions in the contralateral kidney 1 year and 3 1/2 years after the first surgery. Both patients were treated with partial nephrectomy. All patients are alive at 3-14 years (mean 6.6 years) after operation.

Adult onset of renal angiomyolipoma in a patient with tuberous sclerosis

The growth of renal angiomyolipomas in adult tuberous sclerosis patients has not been previously reported. We report one such case of the growth of an angiomyolipoma in a previously documented angiographically normal appearing kidney after the contralateral kidney was removed for angiomyolipoma 15 years earlier.