Hepatic perivascular epithelioid cell tumors: The importance of preoperative diagnosis

Accurate preoperative diagnosis is highly important for the treatment of perivascular epithelioid cell tumors (PEComas) because PEComas are mainly benign tumors and may not require surgical intervention. By analyzing the causes, properties and clinical manifestations of PEComas, we summarize the challenges and solutions in the diagnosis of PEComas.

Microscopic Kidney Disease in Tuberous Sclerosis Complex and Treatment With mTOR Inhibition

Declining kidney function in tuberous sclerosis complex (TSC) is often attributed to large lesions, including angiomyolipomas (AMLs) and cysts, that encroach on the normal parenchyma or that require intervention and loss of parenchyma from surgical debulking or embolization. Consequently, research on inhibitors of the mammalian target of rapamycin (mTOR), a protein complex implicated in TSC pathophysiology for its role in promoting cell growth and proliferation, has largely focused on their ability to reduce AML size. Clinical guidelines distilled from this research limit mTOR inhibition as a first-line treatment to patients with large AMLs. However, chronic kidney disease (CKD) occurs in patients without large AMLs or a history of renal intervention. Alternate mechanisms postulated for CKD in TSC may suggest a role for mTOR inhibition in this population. In this report, we present 2 cases of a microscopic variant of TSC kidney disease causing declining kidney function, as well as anecdotal evidence for the use of mTOR inhibition to improve kidney function in the absence of large AMLs. We highlight the importance of annual kidney function assessment in patients with TSC and suggest a low threshold for kidney biopsy in patients with declining glomerular filtration rate without a clear etiology clinically or radiographically.

Comparison of Polyvinyl Alcohol Versus Combination of Lipiodol-Bleomycin Emulsion and NBCA-Lipiodol Emulsion for Renal Angiomyolipoma Embolization: A Prospective Randomized Study

BACKGROUND. Consensus is lacking regarding optimal embolic agents for transarterial embolization (TAE) of renal angiomylipomas (AMLs). OBJECTIVE. To compare the safety and efficacy of TAE with polyvinyl alcohol (PVA), and of TAE with combination of lipiodol-bleomycin emulsion (LBE) and N-Butyl cyanoacrylate (NBCA)-lipiodol emulsion, for the treatment of patients with large or symptomatic AMLs. METHODS. This prospective study enrolled patients referred for TAE of a large (>4 cm) or symptomatic renal AML from July 2007 to December 2018. Patients were randomized to undergo TAE using PVA particles or combination of LBE and NBCA-lipiodol emulsion. Patients underwent serial clinical follow-up visits and follow-up CT or MRI examinations after TAE. Outcomes were compared between groups. RESULTS. Seventy-eight patients were enrolled. After exclusions, the analysis included 72 patients (15 male, 57 female; mean age, 35.0 years; 51 with hematuria, 66 with flank pain), 35 randomized to treatment by PVA and 37 randomized to treatment by combination of LBE and NBCA-lipiodol emulsion. Complete occlusion of all angiographically visible arterial supply was achieved in all patients. No major adverse event occurred in any patient. Mean follow-up after TAE was 77±45 months (range, 37-180 months). Frequency of resolution of hematuria after initial TAE without recurrence was greater after treatment by LBE and NBCA-lipiodol than by PVA (100.0% vs 80.0%, p=.03). At 12-month follow-up, frequency of complete resolution of flank pain was higher after treatment by LBE and NBCA-lipiodol emulsion than by PVA (100.0% vs 75.0%, p=.04). Mean reduction in AML volume at ≥36 months versus at baseline was greater in patients treated by LBE and NBCA-lipiodol than by PVA (98.0% vs 85.7%, p=.04). Frequency of complete response by mRECIST criteria at ≥36 months was greater in patients treated by LBE and NBCA-lipiodol than by PVA (94.6% vs 74.3%, p=.04). Rate of repeat TAE was higher among patients treated by PVA than by LBE and NBCA-lipiodol (25.7% vs 8.1%, p=.03). CONCLUSION. Superior outcomes after TAE of AML were achieved using LBE and NBCA-lipiodol than using PVA. CLINICAL IMPACT. TAE using combination of LBE and NBCA-lipiodol emulsion is a safe and effective treatment option for large or symptomatic AMLs.

Adult renal angiomyolipomas: A retrospective analysis of the histological subtypes and their clinicoradiological correlates

Background

Renal angiomyolipomas (AMLs) are rare, benign mesenchymal tumors of the kidney. Asian data on the prevalence of the subtypes of AMLs and their association with tuberous sclerosis are sparse prompting us to evaluate the clinicopathological characteristics of these tumors.

Materials and Methods

We included cases diagnosed from 2001 to 2021 extracting demographic details, clinical presentation, syndromic association with tuberous sclerosis, and preoperative clinicoradiological features from the electronic medical records.

Results

Ninety-five cases of adult renal AML were diagnosed among 2402 renal tumors, a prevalence of 3.95%. Forty tumors (42%) were detected incidentally; two patients had life-threatening retroperitoneal hemorrhage. Tuberous sclerosis complex (TSC) was associated with ten cases (10.5%). These patients were a decade younger than those in the non-TSC group (P = 0.008) and had bilateral, multiple, and larger tumors (P = 0.0009, 0.001, and 0.047, respectively). Microscopically, classic and epithelioid subtypes were seen in 87 (91.6%) and 8 cases (8.4%), respectively. Hemorrhage was more common in the epithelioid subtype (P = 0.13). HMB-45, melan-A, and smooth muscle actin immunohistochemistry were useful in cases which lacked the prototypical classic histology and for confirming a diagnosis of epithelioid AML.

Conclusions

The prevalence of renal AML in our series was four times higher, and the mean age at diagnosis was a decade earlier than that reported in Western literature but similar to data from two Asian countries. Similar studies from other countries will help ascertain if these differences in prevalence can be attributed to ethnic differences.

[Prevalence of the tuberous sclerosis complex at patients taken care for a renal angiomyolipoma]

INTRODUCTION

Bourneville's tuberous sclerosis or Tuberous Sclerosis Complex (TSC) is an autosomal dominant hereditary phakomatosis associated with angiomyolipomas (AML) of the kidney. The aim of this study was to identify the prevalence of TSC in patients diagnosed and cared for AML in our department of urology.

MATERIALS AND METHODS

All the patients with AML were included between March 2009 and June 2016 in a French university hospital. Each patient was reviewed in consultation with a clinical examination and imaging. Specific clinical criteria were used to refer patients to genetic analysis. Patients with a high TSC probability had a genetic analysis to search TSC1 and TSC2 genes mutations.

RESULTS

In all, 28 patients were included and 3 (11%) were diagnosed TSC. The median age of the patients was 62 years (36-82 years). The most frequent clinical criteria were facial angiofibromas in 7 patients (25%). Among the 8 patients (29%) with evocative clinical criteria, a mutation of the TSC1 and TSC2 genes was identified in 3 patients (11%) with a diagnosis of TSC made before the AML diagnosis.

CONCLUSION

In this study, 8 patients (29%) presented clinical criteria suggestive of TSC, preferentially dermatological. The diagnosis was confirmed by screening TSC1 and TSC2 genes mutations in 3 patients (11%), nevertheless prevalence of TSC is most probably underestimated by the genetic mosaïcisme of this pathology.

Comparisons of the safety and effectiveness of robot-assisted versus laparoscopic partial nephrectomy for large angiomyolipomas: a propensity score-matched analysis

OBJECTIVE

To compare the safety and effectiveness of robot-assisted partial nephrectomy (RAPN) versus laparoscopic partial nephrectomy (LPN) for large angiomyolipomas (AMLs).

MATERIALS AND METHODS

We retrospectively evaluated 150 patients who were treated with either RAPN or LPN for large angiomyolipomas from 2014 to 2018. Propensity score matching was performed on age, gender, BMI, Charlson Comorbidity Index, tumour side and size, preoperative eGFR and RENAL score.

RESULTS

In total, 63 and 87 patients underwent RAPNs and LPNs, respectively. There were more large and complex AMLs in the RAPN cohort, with the median tumour maximal diameters and RENAL scores differing between the two groups (8 versus 7 cm and 9 versus 8, P = 0.01). After matching, the median warm ischemic time was significantly shorter in the RAPNs versus the LPNs (17 versus 22 min, P = 0.001). The rate of intraoperative complications in the RAPNs appeared lower than the LPNs (3.2% versus 8.1%). The median postoperative length of stay was significantly shorter in the RAPN cohort than the LPNs (P = 0.001). Twelve months after surgery, RAPNs received a 94.6% renal function prevention; while this was 90.8% in LPNs (P = 0.001). Subgroup analysis indicated that prior selective arterial embolization (SAE) was related to better renal function preservation in the RAPN cohort (P = 0.01). No recurrence occurred in either of the two cohorts.

CONCLUSIONS

RAPN is a safe and effective alternative to LPNs for large AMLs with a shorter warm ischemic time and higher renal preservation rate. Recurrence was equivalent in both RAPNs and LPNs.

Recommendations for the management of renal involvement in the tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a rare, hereditary, multisystemic disease with a broad phenotypic spectrum. Its management requires the collaboration of multiple specialists. Just as in the paediatric age, the paediatric neurologist takes on special importance; in adulthood, renal involvement is the cause of the greatest morbidity and mortality. There are several recommendations on the general management of patients with TSC but none that focuses on renal involvement. These recommendations respond to the need to provide guidelines to facilitate a better knowledge and diagnostic-therapeutic management of the renal involvement of TSC through a rational use of complementary tests and the correct use of available treatments. Their elaboration has been based on consensus within the hereditary renal diseases working group of the SEN/REDINREN (Spanish Society of Nephrology/Kidney Research Network). It has also counted on the participation of non-nephrologist specialists in TSC in order to expand the vision of the disease.

CT characteristics predict the response to everolimus or sirolimus of renal angiomyolipomas in patients with tuberous sclerosis complex

OBJECTIVE

To investigate factors influencing the volume response of everolimus and sirolimus in tuberous sclerosis complex (TSC) associated-angiomyolipomas (AML).

METHODS

A retrospective analysis of 30 cases of TSC-AML treated by mTOR inhibitors (everolimus 18 cases, and sirolimus 12 cases) between April 2014 and November 2017 at our center was carried out. Epidemiological data, therapeutic response and influence factors were reviewed and analyzed. Age, sex, associated with SEGA and/or LAM or not, plasma rapamycin concentration, AML volume at baseline, and mean CT value of AML in the maximum cross-section at baseline were analyzed as potential influencing factors.

RESULTS

Eighteen patients with 32 lesions in everolimus group and 12 patients with 15 lesions in sirolimus group were included. There was no statistically significant difference of baseline characteristics except for involved side (P = 0.008) between two groups. The mean volume of AML was 1000 ± 1276 cm³ at baseline and 633 ± 1121 cm³ at 6 months after treatment (P < 0.001) in everolimus group, and 1984 ± 2861 cm³ at baseline and 1733 ± 2533 cm³ at 6 months after treatment (P = 0.001) in sirolimus group, respectively. The mean volume reduction of the AML in everolimus and sirolimus groups were 55.56% ± 23.79% and 30.5% ± 22.8% (P = 0.001). Stepwise multiple linear regression analysis revealed that factors influencing the short-term volume response of everolimus and sirolimus for TSC-associated AML were AML volume at baseline (P < 0.001 and 0.038, respectively) and mean CT value at baseline (P < 0.001 and 0.020, respectively). The rates of ≥ 50% volume reduction in high CT value group was much higher than that in low CT value group (90.5% vs. 18.2%, P < 0.001).

CONCLUSIONS

Everolimus at 10 mg daily might be more effective than sirolimus at 2 mg daily in treatment of patients with TSC-AML. AML volume and mean CT value at baseline were factors influencing the short-term volume response of everolimus or sirolimus for TSC-AML.

The ominous sequence in patients with tuberous sclerosis complex

BACKGROUND

The clinical phenotypes and their severity in patients with tuberous sclerosis complex can be quite variable and are sometimes never determined simply by the primary mutation. These make clinically selecting appropriate treatments and predicting disease outcome difficult. In this report, the prognostic ominous sequence was evaluated in association with clinical manifestations and gene mutations.

METHODS

The patients were classified by each renal lesion of angiomyolipomas and polycystic disease. The other clinical manifestations and outcomes of epilepsy, mental retardation, facial angiofibromas, subependymal giant cell astrocytoma, cortical tubers were reviewed and each gene mutations were analyzed in seven unrelated patients.

RESULTS

Two patients with multiple and large proliferative renal angiomyolipoma showed poor clinical outcome than the patients with other renal lesions. These patients presented with progressively proliferative facial angiofibroma, West syndrome, Lennox-Gastaut syndrome, severe mental retardation, subependymal giant cell astrocytoma and they were affected by TSC2 gene mutations.

CONCLUSION

The sequence of progressively proliferative renal angiomyolipoma, facial angiofibroma, West syndrome and TSC2 gene mutations might be prognostic ominous factors.

Giant bilateral renal angiomyolipomas and lymphangioleiomyomatosis presenting after two successive pregnancies successfully treated with surgery and rapamycin

We report the case of a 25-year-old woman who presented with abdominal and flank pain with two successive pregnancies and was diagnosed of giant bilateral renal AMLs and pulmonary LAM associated with TSC in the post-partum of her second pregnancy. This case illustrates that in women with TSC rapid growth from renal AMLs and development of LAM may occur with successive pregnancies. It also stresses the potential for preservation of renal function despite successive bilateral renal surgery of giant AMLs. Moreover, the treatment with a low-dose rapamycin may be an option for LAM treatment. Finally, a low-dose rapamycin may be considered as an adjuvant treatment together to kidney-sparing conservative surgery for renal AMLs.

Clinically relevant imaging in tuberous sclerosis

Tuberous sclerosis (TS), also known as Bourneville disease or Bourneville–Pringle disease, is an autosomal dominant genetic disorder classically characterized by the presence of hamartomatous growths in multiple organs. TS and tuberous sclerosis complex (TSC) are different terms for the same genetic condition. Both terms describe clinical changes due to mutations involving either of the two genes named TSC1 and TSC2, which regulate cell growth. The diagnosis of TSC is established using diagnostic criteria based on clinical and imaging findings. Routine screening and surveillance of patients with TSC is needed to determine the presence and extent of organ involvement, especially the brain, kidneys, and lungs, and identify the development of associated complications. As the treatment is organ specific, imaging plays a crucial role in the management of patients with TSC.