Contemporary Diagnosis and Management of Renal Angiomyolipoma:

Sequential everolimus for angiomyolipoma associated with tuberous sclerosis complex: a prospective cohort study

Background

To evaluate the efficacy, safety and health economics of sequential everolimus in treating angiomyolipoma (AML) associated with tuberous sclerosis complex (TSC).

Methods

In this prospective cohort study, patients met the inclusion criteria received standard or sequential treatment according to their willingness. All patients received an initial dose of everolimus (10 mg oral, once a day) for 3 months. The standard treatment group maintained 10 mg QD for 12 months, while the sequential treatment group reduced the dose to 5 mg QD from the 4th month. The efficacy, serum everolimus concentration and safety were evaluated at 1, 3, 6, 9 and 12 months after treatment. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in the total volume of target AML relative to baseline.

Results

Between June 1, 2016 and June 1, 2017, a total of 53 patients were included. Twenty-three patients received standard treatment, 30 patients received sequential treatment. At 1, 3, 6, 9 and 12 months after treatment, the proportion of patients whose total target tumor volume decreased by ≥ 50% from baseline was 39.1% versus 36.7%, 43.5% versus 56.7%, 47.8% versus 50%, 47.8% versus 60% and 47.8% versus 23.3% respectively (P > 0.05 for all). The overall response rate of skin lesions in the two groups was 40.4%, and the response rates of skin lesions at different times were similar for two groups (P > 0.05 for all). Major adverse effects (AEs) included mouth ulceration, hypertriglyceridemia, hypercholesterolemia, menstrual disorders. There was no significant difference between the two groups in the incidence of AEs at 3 months after treatment. The incidence of overall and grade 3/4 AEs at 12 months after treatment were significantly lower in the sequential treatment group. The average direct cost of the two groups in 12 months was $15,466 and $11,120, respectively.

Conclusions

Compared to standard treatment, sequential treatment was equally effective, with a lower incidence of adverse events and a lower direct cost, suggesting that it may be an alternative treatment for AML associated with TSC.

A review of clinical and MR imaging features of renal lipid-poor angiomyolipomas

BACKGROUND

Lipid-poor angiomyolipomas (lpAMLs) constitute up to 5% of renal angiomyolipomas and are challenging to differentiate from malignant renal lesions on imaging alone. This review aims to identify clinical and MRI features which can be utilized to improve specificity and diagnostic accuracy for detecting lpAMLs in patients being considered for active surveillance rather than intervention.

FINDINGS

Young age, female sex, and small lesion size are associated with lpAMLs in studies evaluating indeterminate renal lesions. The accuracy of criteria using T2-weighted imaging, diffusion-weighted imaging, chemical shift imaging, dynamic contrast enhancement, multiparametric imaging, and radiomics are reviewed. Low T2 signal intensity is a particularly important MRI feature for lpAML. In studies with low T2 signal intensity, homogeneous early enhancement is a typical feature with an arterial-to-delay enhancement ratio > 1.5. Intratumoral hemorrhage with decrease in signal intensity on in-phase chemical shift imaging may be particularly useful for differentiating papillary renal cell carcinomas from lpAMLs in low T2 signal intensity lesions. Combining clinical and multiparametric MRI features can result in near-perfect specificity for lpAML. In select patients, clinical and MRI features can result in a high specificity and diagnostic accuracy for lpAMLs. These lesions can be considered for active surveillance rather than invasive diagnostic and therapeutic procedures such as biopsy or surgery.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study

Background

Tuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70–80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC.

Methods

All patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC.

Results

Complete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p <  0.01). 37 (7%) of the 521 patients were within the age-range of 18–40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p <  0.05), and 2 (33.3%) of which with a single, unilateral AML (p <  0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p <  0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2–344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01–0.88; p = 0.04)) to be a risk factor for TSC.

Conclusions

The presence of bilateral AML in patients within the age-range of 18–40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Successful endovascular treatment of spontaneous intrarenal pseudoaneurysm in a case of tuberous sclerosis

Tuberous sclerosis is a complex disorder which has multisystem involvement and varied clinical manifestations. Almost half of the patients have associated angiomyolipoma which contains fat, vascular and smooth muscle components. Spontaneous pseudoaneurysm formation is a complication of angiomyolipoma. Here we present a case of a female child presenting with hematuria who after thorough clinical and radiological investigations was diagnosed as a case of tuberous sclerosis with right intrarenal pseudoaneurysm. She was successfully treated with endovascular coil embolization.

Spontaneous rupture of enormous renal angiomyolipoma in a pregnant tuberous sclerosis patient: a rare case

Background

Renal angiomyolipoma (RAML) is a rare benign kidney tumour comprised of adipose tissue, smooth muscle, and blood vessels. It can cause fatal complications if it ruptures. Although there have been reports of RAMLs rupturing, it is unusual to see RAMLs rupture during pregnancy, especially in pregnant women with tuberous sclerosis (TSC). Moreover, we reported a rare complication after selective arterial embolization (SAE) for the first time, which called aseptic liquefaction necrosis.

Case presentation

The case is a 16-week-pregnant woman with TSC who presented with severe flank pain, which was secondary to the rupture of a large, previously unknown RAML. This was confirmed by emergency computed tomography and successfully treated with selective arterial embolization after the patient received counselling and provided prior informed written consent for medical termination of pregnancy (MTP). The patient underwent abortion 3 weeks after the SAE. The patient required drainage 2 months after the SAE because of aseptic liquefaction necrosis. During follow-up, the patient’s lesion remained stable.

Conclusion

RAML rupture is a rare but rather serious complication in pregnant tuberous sclerosis patients. Selective arterial embolization (SAE) should be performed immediately, and the status of the pregnancy needs to be assessed by a multidisciplinary team. We also report for the first time the rare complication of aseptic liquefaction necrosis after SAE of RAML, for which percutaneous drainage is effective.

Conservative treatment of monolateral giant renal angiomyolipoma in a patient with Tuberous Sclerosis Complex (TSC): A case report

Tuberous sclerosis complex has several renal manifestations like angiomyolipomas. We report a case of a giant AML and discuss its diagnosis and treatment. A 42-year-old woman was admitted to emergency department due to flank pain and hematuria. The patient had history of mental retardation and epilepsy. Abdominal CT without contrast medium revealed a large mass with a fat/blood content inside. On those findings, we diagnosed the patient a bleeding giant AML. We performed selective embolization of the bleeding source with subsequent conservative management. TSC-associated AMLs occur more frequently as multiple lesions and grow to larger size than idiopathic AML.

A scoring system based on clinical features for the prediction of sporadic renal angiomyolipoma rupture and hemorrhage

The purpose of this study is to analyze the risk factors of sporadic renal hamartoma and establish a risk scoring system, and to intervene in patients with high-risk sporadic renal hamartoma who are prone to rupture and bleeding as soon as possible.Retrospective univariate and multivariate logistic analyzes were conducted for clinical data of 332 sporadic renal hamartoma patients to screen out independent risk factors of tumor rupture. Score of each independent risk factor was calculated. (Calculation formula: the risk coefficient of each factor = the beta regression coefficient of each factor/the minimum value of the beta regression coefficient of all factors, the value of the smallest beta regression coefficient corresponding to all the factors was assigned 1 point. The score of each factor was equal to the risk coefficient of each variable was taken as an integer value by rounding.) The total score was equal to the sum of all factors. Then the area under the receiver operating characteristics (AUC) curve was compared between high risk factors and scoring system. Finally, the scoring system was evaluated by the area under the curve (AUC) and the Hosmer-Lemeshow method in an independent cohort of 130 patients.Factors such as symptoms at presentation, tumor size, tumor blood supply, and tumor growth pattern were significant predictors of sporadic renal angiomyolipoma rupture in both the univariate and multivariate analyses; these predictors were included in the scoring system to predict sporadic renal angiomyolipoma rupture. There were no significant differences in AUCs between high risk factors and scoring system (z = 0.6434, P = .583, AUC = 0.913, and 0.903 for high risk factors and scoring system, respectively). The sporadic renal angiomyolipoma patients who scored >6 points were prone to rupture. AUROC of the scoring system in the validation set was 0.854(95%CI:0.779, 0.928). Using the Hosmer-Lemeshow method, the value of X was 2.916, P = .893, suggesting the scoring system fitted well.A scoring system based on clinical features is simple and effective in predicting sporadic angiolipoma rupture and hemorrhage. When the score is higher than 6 points, the probability of hamartoma rupture and hemorrhage is significantly increased and early intervention is needed.

Emergency retroperitoneal laparoscopic partial nephrectomy for ruptured renal angiomyolipomas: a retrospective single-center series of 15 cases

Background

To assess the safety, tumor control and renal function preservation of the emergency retroperitoneal laparoscopic partial nephrectomy (LPN) for ruptured renal angiomyolipoma (AML) and summarize our single-center initial experience.

Methods

We performed a retrospective analysis of 15 patients pathologically confirmed renal AML treated with emergency retroperitoneal LPN between January 2016 and May 2019. The patient demographics, operation time, blood loss, transfusion requirements, complications and other surgical parameters were analyzed. Follow-up was performed by serum creatinine and imaging modalities.

Results

Fifteen patients were performed with emergency LPN with the median age 41.6 years. The mean size of the renal AMLs was 7.8 cm. The mean size of the retroperitoneal hematomas was 8.5 cm. All the emergency surgeries were performed successfully without any conversion to nephrectomy or open surgery. The mean operative time was 101 min. The mean warm ischemia time was 28 min. The mean estimated blood loss was 311 ml. Five patients required intraoperative blood transfusion (33.3%, 5/15). The mean transfused RBC was 4 U (range 2-6 U), and the mean transfused plasma was 200 ml (range 200-400 ml). The mean drainage duration was 3 days (range 2–5 days). The mean postoperative hospitalization was 4.7 days. No patients experienced intraoperative complications. The mean serum creatine was slightly higher after surgery (53.1 vs. 55.9 μmol/L). One patient had postoperative perirenal fluid collection. No patients needed dialysis. No recurrence was observed in the patients at the median follow-up of 24.1 months.

Conclusions

Our initial experience shows that the emergency retroperitoneal LPN is a safe, minimally invasive procedure for emergency patients with ruptured renal AMLs. It could be considered as an effective alternative to renal artery embolization in selected emergency patients.

Selective Arterial Embolization for Large or Symptomatic Renal Angiomyolipoma: 10 Years of Follow-up

OBJECTIVE

To assess long-term outcome after selective arterial embolization (SAE) as first-line treatment for large or symptomatic AML.

DESIGN, SETTING, AND PARTICIPANTS

Data from a prospectively maintained database on 71 patients who underwent SAE for large or symptomatic AML were reviewed. Patients with sporadic and tuberous-sclerosis-complex (TSC) were included.

OUTCOME MEASUREMENTS

The main endpoints were re-embolization rates, occurrence of clinical events related to AML, size of AML, and renal function.

RESULTS

Thirteen (19.1%) patients reported at least 1 major clinical event. Major complications affected 2 patients (2.9%), both ending in complete loss of renal unit function. Four renal units (5.9%) were eventually treated surgically. The re-embolization rate was 41.1%, with an average time from the initial to a repeat SAE of 2.18 years (range 0.31-10.65 years). The size of the tumor prior to SAE and after 5 and 10 years of follow-up were 8.9 cm (7-12), 6.5 cm (4-7.5), 7 cm (4-7.8), respectively [median (IQR)]. These results are translated to a size reduction of 27% in 10 years follow-up. Patients with TSC had larger tumors on long-term follow-up (77.8 vs 41.3 mm, P = .045). The long-term follow-up estimated average glomerular filtration rate was 81.97 (range 26-196). No patient needed renal replacement therapy, and disease-specific survival was 100%.

CONCLUSIONS

SAE is a safe treatment option for patients with symptomatic or large AML. It represents a minimally invasive intervention with good long-term outcome. SAE may be offered as first-line treatment in most cases, though, it is associated with high retreatment rates.

Evidence for a role of geranylgeranylation in renal angiomyolipoma and renal epithelioid angiomyolipoma

Research on mevalonate kinase deficiency has revealed that it may lead to the development of renal angiomyolipomas (RAMLs). Thus, it was suspected that geranylgeranyl pyrophosphate synthase (GGPPS), a key enzyme in the mevalonate pathway, may be involved in the development of RAMLs. In the present study, the expression of GGPPS in RAMLs and renal epithelioid angiomyolipomas (REAs) was assessed, and paraffin embedded specimens from 60 patients, including 9 cases with REA and 51 cases with RAML, were examined. Immunoreactivity was evaluated semi-quantitatively according to the intensity of staining and the percentage of positively stained cells. The results indicated that GGPPS was predominantly present in the cytoplasm, and REA tissues exhibited higher expression of GGPPS in the cytoplasm compared with RAML tissues. It was also identified that GGPPS was upregulated in TSC2-null cells, and inhibition of GGPPS could induce apoptosis of TSC2-null cells by autophagy. In conclusion, the increased expression of GGPPS in RAMLs and REAs indicated that mevalonate pathways may be involved in disease progression. GGPPS may serve as a potential therapeutic target and the current results may provide a novel therapeutic strategy for RAML and lymphangioleiomyomatosis.

Late local, peritoneal and systemic recurrence of renal angiomyolipoma: A case report

Renal angiomyolipoma (AML) is a relatively rare tumor that is generally considered as merely benign. However, epithelioid AML (EAML), an uncommon subtype, is associated with potentially malignant behavior. We herein present the case of a 60-year old male patient who had undergone left nephrectomy with left adrenalectomy and lymphadenectomy for a renal tumor 12 years earlier, and presented to our hospital with dull abdominal pain. The histology report after the previous surgery had revealed an AML of the left kidney with a maximal diameter of 17 cm. Imaging studies demonstrated a large tumor of 13 cm in diameter in the area of the resected kidney, as well as hepatic and peritoneal metastases. Computed tomography-guided core needle biopsy of the mass and revision of the histology of the nephrectomy revealed an EAML. Four years after a two-stage resection of the recurrences the patient is in excellent condition and free of disease. From this case report and the literature review on EAML, it appears that correct histological diagnosis of this subtype of renal AML is crucial. Erroneous diagnosis of simple renal AML instead of EAML may lead to insufficient postoperative management. Clinicians should be aware of the malignant potential of EAML and the need for long-term follow-up. As effective surgical and emerging medical treatment options are available, timely detection of recurrent disease may lead to improved outcome.

Tuberous sclerosis syndrome: a typical case of a rare disease

The article is devoted to a rare hereditary disease from the group of phak omatoses with an autosomal dominant type of inheritance — Pringle — Burnevill disease. The questions of the prevalence of the disease, the variability of the clinical picture, the timeliness of the clinical diagnosis are considered. Particular attention is paid to skin manifestations and their differential diagnosis. A clinical case of this disease is described.

Two in One: Epithelioid angiomyolipoma within a classic kidney angiomyolipoma - a case report

Background

Epithelioid angiomyolipoma is defined as potentially malignant mesenchymal neoplasm, characterized by proliferating epithelioid cells, whereas classic angiomyolipoma, composed of fat, smooth muscle cells and dysmorphic vessels, is defined as a potentially benign. The usual or classic angiomyolipoma is often found incidentally on imaging studies, relatively easily identified due to the presence of fat, in contrast to the epithelioid angiomyolipoma that can pose diagnostic challenges.

Case presentation

We report a 51-year-old female patient in which an ultrasonography examination showed a solid mass close to the right renal pelvis with hypoechoic and hyperechoic areas. A differential diagnosis of atypical sinus lipomatosis, lipoma and a transitional cell carcinoma was postulated whereas in a subsequent computed tomography a classic angiomyolipoma was postulated. A re-examination by contrast enhanced ultrasound revealed a striking perfusion difference of the hypoechoic and hyperechoic areas. The hypoechoic area showed homogenous and prolonged enhancement whereas the hypoechoic area displayed a marked slower contrast material flooding and a relatively rapid wash out. The histological analysis from the biopsy of the hyperechoic area showed a classic angiomyolipoma, whereas the sample of the hypoechoic central portion revealed an epithelioid angiomyolipoma. A nephrectomy was performed because of the malignant potential of the epithelioid variant of the angiomyolipoma.

Conclusions

A solid kidney mass with two sharply defined parts, one-part compatible with a classical angiomyolipoma and the other being suspected of carcinoma, is rare, but also illustrative and instructive. The combination of different imaging modalities in the work up of a solid renal mass facilitated to discriminate benign from malignant areas.

Natural history of patients with tuberous sclerosis complex related renal angiomyolipoma

OBJECTIVE

To examine temporal relationships between tuberous sclerosis complex (TSC) and renal angiomyolipoma diagnosis and outcomes, treatment, and healthcare utilization.

METHODS

Administrative data from the MarketScan Commercial Database was used to select TSC-related renal angiomyolipoma patients during 1 January 2000-31 March 2013. Patients were followed until the earliest of inpatient death or end of enrollment or study. Occurrence of kidney-related outcomes, kidney-related procedures, and all-cause healthcare utilization and time to occurrence were reported. Kaplan-Meier curves were used to display the unadjusted distribution of time to outcome.

RESULTS

A total of 605 patients were selected (<18 years N = 225; ≥18 years N = 380). Mean time from TSC to renal angiomyolipoma diagnosis was 25.7 months in younger and 16.9 months in older patients. Patients ≥18 years had higher rates of chronic kidney disease (CKD), hematuria, kidney failure, embolization (EMB), and partial and complete nephrectomy compared to patients <18 years (all p < .05). Mean time from TSC-related renal angiomyolipoma diagnosis to CKD, hematuria, kidney failure, EMB, first emergency room and inpatient visits was shorter in older compared to younger patients (all p < .05). Probability of developing CKD was approximately 0.8 and 0.95 within 3 years in younger and older patients, respectively.

CONCLUSIONS

Patients with TSC-related renal angiomyolipoma had high rates of kidney-related outcomes and procedures. These events sometimes preceded the angiomyolipoma diagnosis. A key study limitation was that due to the small sample size, results may have been biased by outliers. Research is needed to determine whether earlier angiomyolipoma diagnosis can impact occurrence of events and reduce healthcare utilization.

Outcomes of angioembolization and nephrectomy for renal angiomyolipoma associated with tuberous sclerosis complex: a real-world US national study

OBJECTIVE

To examine outcomes of clinical procedures for renal angiomyolipoma associated with tuberous sclerosis complex (TSC) based on US national health claims databases.

METHODS

This retrospective cohort study selected two cohorts of TSC patients, who underwent either embolization or nephrectomy (either partial or complete) for renal angiomyolipoma in the years from 2000 through 2011. Based on claims diagnosis codes, we estimated the prevalence rates of 10 angiomyolipoma-related conditions and 50 embolization- or nephrectomy-related conditions in the pre- and post-baseline periods respectively, and made cross-year and cross-period comparison of these rates with repeated measures analysis methods.

RESULTS

The embolization cohort (N = 4280) and the nephrectomy cohort (N = 3842) had mean baseline ages of 50.7 and 51.7 years with 52.5% and 51.3% males, respectively. After the intervention, the embolization cohort had statistically significant reductions (all p < .05) in gross hematuria (-27.7%), retroperitoneal hemorrhage (-8.4%), and abdominal mass (-6.9%), and increases in hypertension (15.5%), renal mass or unspecified disorder of kidney and ureter (13.8%), anemia (5.1%), and renal insufficiency (3.3%). Similarly, the nephrectomy cohort saw statistically significant reductions (all p < .05) in gross hematuria (-30.6%), flank pain (-7.5%), and abdominal mass (-6.4%), but increases in hypertension (11.9%), renal insufficiency (10.4%), and anemia (7.6%). Embolization was associated with post-procedure increases in renal mass or unspecified kidney/ureter disorder (13.9%), other disorders of kidney and ureter (3.4%), non-acute renal insufficiency (3.1%), flank pain (3.7%), renal insufficiency (3.2%), etc. (all p < .05). Nephrectomy was associated with post-procedure increases in postoperative ileus (5.3%), pain and headache (4.8%), paralytic ileus (3.6%), etc. (all p < .05).

CONCLUSIONS

Both embolization and nephrectomy were effective, but associated with increases in certain angiomyolipoma-related conditions. Further, the embolization effect on gross hematuria, retroperitoneal hemorrhage, and abdominal mass might subside after the intervention year.

Giant bilateral renal angiomyolipomas: a case report

Angiomyolipoma (AML) is a mesenchymal renal tumor composed of variable proportions of adipose tissue as well as vascular and smooth muscle elements. It can cause important, potentially life-threatening complications. The aim of this case report is to show a conservative treatment modality of this disease. A 50-year-old man underwent ultrasonography and then computed tomography showing the presence of bilateral renal masses of 27.5 × 19.5 × 21 cm on the left kidney and 28.5 × 19.6 × 27.5 cm on the right, respectively. Serum creatinine was normal; an ultrasonography-guided biopsy of the left kidney did not allow a diagnosis with absolute certainty, but was suggestive of AML. The patient also underwent total body magnetic resonance imaging, which was negative for pathological findings. He underwent a strict regime of surveillance with magnetic resonance imaging every 4-5 months, and at the last follow-up he was asymptomatic and serum creatinine was still normal. The management of giant AML is a complex and multifactorial decision. Patients can knowingly choose an active surveillance program, even in case of giant AMLs.

Frequency of undiagnosed cystic lung disease in patients with sporadic renal angiomyolipomas

OBJECTIVE

The aim of this study was to assess the frequency of undiagnosed cystic lung lesions suggestive of pulmonary lymphangioleiomyomatosis (LAM) in patients who received a diagnosis of sporadic renal angiomyolipomas (AMLs).

METHODS

We conducted a retrospective review of CT scans of the chest or abdomen for cystic lung lesions on 176 adult patients who received a diagnosis of sporadic renal AML during a 10-year period, 1997 to 2006, and comparison with chest CT scans of 176 control subjects without renal AML but matched for age, sex, and smoking history. Patients presenting with suspected or known pulmonary LAM and those with underlying tuberous sclerosis were excluded.

RESULTS

Sporadic renal AML was diagnosed in 176 patients with a median age of 58 years (range, 20-91 years), the majority of whom were women (81.8%). Renal tumor was an incidental finding on imaging studies for most patients (90.3%). Nineteen patients (10.8%) had one or more cystic lung lesions and included nine patients (5.1%) with four or more cysts, all of whom were women. In comparison, eight control subjects (4.6%) had one to three cystic lung lesions and none of them exhibited four or more cysts. None of the patients with renal AML and cystic lung lesions, including six women with 10 or more cysts, had undergone an evaluation of their cystic lung disease.

CONCLUSIONS

We conclude that a significant portion of women with sporadic renal AMLs exhibit cystic lung lesions suggestive of pulmonary LAM but may remain undiagnosed. Coexistence of pulmonary LAM should be considered in women incidentally found to have sporadic renal AMLs.

Conservative management of giant symptomatic angiomyolipomas in patients with the tuberous sclerosis complex

OBJECTIVE

To present two patients with the tuberous sclerosis complex in whom giant angiomyolipomas (AMLs) were managed conservatively for >20 years, as large (>4 cm) symptomatic AMLs are generally treated with embolization or nephrectomy because of the risks of haemorrhage.

PATIENTS AND METHODS

The first patient initially presented with bilateral renal AMLs replacing >70% of his parenchymal volume, and a large left renal cyst. Since presentation he was hospitalized three times, but has had no transfusions or procedures to treat his AMLs. His renal function has remained stable during this 21-year interval. The second patient initially presented with bilateral renal AMLs that were not amenable to nephron-sparing surgery. After removing her nonfunctioning left kidney, the 24-cm AML in her right kidney was managed conservatively for >20 years, during which she had 44 transfusions and 11 hospitalizations before uncomplicated right nephrectomy and subsequent need for haemodialysis.

CONCLUSION

Conservative management of AMLs can preserve renal function for >20 years in patients with tuberous sclerosis at high risk of end-stage renal disease.

Massive epithelioid angiomyolipoma of the kidney in a young girl

We report the case of a huge right renal tumor in a 17-year-old girl. Absence of fat on preoperative magnetic resonance imaging suggested renal cell carcinoma, and surgery was performed. Pathologic evaluation with HMB-45 immunohistochemical staining confirmed the diagnosis of epithelioid angiomyolipoma. The tumor consisted predominantly of epithelioid cells, and it could easily be misidentified as a renal cell carcinoma due to the paucity of the fat component. Previous reports have suggested that epithelioid angiomyolipomas have the potential to be malignant, and thus regular postoperative surveillance is recommended. Our patient had no signs of recurrence at her most recent follow up, 12 months after surgery.

Huge renal angiomyolipomas in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominance disorder with variable penetrance. Renal angiomyolipoma (AML) is one of the commonest urological manifestations. These lesions may cause significant morbidity and mortality. We report two patients with multiple and huge renal angiomyolipomas presenting with gross haematuria. They subsequently underwent unilateral nephrectomy. The difficulty in diagnosis and controversies in management will be briefly discussed.