Efficacy and Safety of Sirolimus for Renal Angiomyolipoma in Patients with Tuberous Sclerosis Complex or Sporadic Lymphangioleiomyomatosis: A Systematic Review

Tuberous Sclerosis Complex and the kidneys: what nephrologists need to know

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by the development of hamartomas in the central nervous system, heart, skin, lungs, and kidneys and other manifestations including seizures, cortical tubers, radial migration lines, autism and cognitive disability. The disease is associated with pathogenic variants in the TSC1 or TSC2 genes, resulting in the hyperactivation of the mTOR pathway, a key regulator of cell growth and metabolism. Consequently, the hyperactivation of the mTOR pathway leads to abnormal tissue proliferation and the development of solid tumors. Kidney involvement in TSC is characterized by the development of cystic lesions, renal cell carcinoma and renal angiomyolipomas, which may progress and cause pain, bleeding, and loss of kidney function. Over the past years, there has been a notable shift in the therapeutic approach to TSC, particularly in addressing renal manifestations. mTOR inhibitors have emerged as the primary therapeutic option, whereas surgical interventions like nephrectomy and embolization being reserved primarily for complications unresponsive to clinical treatment, such as severe renal hemorrhage. This review focuses on the main clinical characteristics of TSC, the mechanisms underlying kidney involvement, the recent advances in therapy for kidney lesions, and the future perspectives.

Genetic susceptibility in children, adolescents, and young adults diagnosed with soft-tissue sarcomas

Soft tissue sarcomas (STS) may arise as a consequence of germline variants in cancer predisposition genes (CPGs). We believe that elucidating germline sarcoma predisposition is critical for understanding disease biology and therapeutic requirements. Participation in surveillance programs may allow for early tumor detection, early initiation of therapy and, ultimately, better outcomes. Among children, adolescents, and adults diagnosed with soft-tissue sarcomas and examined as part of published germline sequencing studies, pathogenic/likely pathogenic (P/LP) variants in CPGs were reported in 7-33% of patients. P/LP germline variants were detected most frequently in TP53, NF1 and BRCA1/2. In this review, we describe reported associations between soft tissue sarcomas and germline variants in CPGs, with mentioning of locally aggressive and benign soft tissue tumors that have important associations with cancer predisposition syndromes. We also discuss recommendations for diagnostic germline genetic testing. Testing for sarcoma-predisposing germline variants should be considered as part of the routine clinical workup and care of any child, adolescent, or adult diagnosed with STS and take into account consequences for the whole family.

Efficacy of Sirolimus Treatment in PEComa-10 Years of Practice Perspective

Perivascular epithelioid cell tumors (PEComa) represent a family of rare mesenchymal tumors resultant from deregulation in mTOR pathway activity. The aim of this study is to evaluate the long-term efficacy of targeted PEComa treatment. We reviewed all consecutive patients with PEComa who started systemic treatment with sirolimus in our reference sarcoma center between January 2011 and August 2020. Histopathology of PEComa was reviewed and confirmed in all cases by a designated sarcoma pathologist. Any surviving progression-free patients were censored at the last follow-up (31 March 2021). Survival curves were calculated according to Kaplan-Meier method and compared with the log-rank test or a Cox proportional hazard model. Fifteen (12 females and 3 males) consecutive PEComa patients were treated. The median age of patients treated systemically was 50 years. Median progression-free survival (PFS) was 4.9 months (95% CI: 3.8-NA) for first-line chemotherapy and was not reached (95% CI: 42.0-NA) for sirolimus as first-line therapy. There was one objective response (OR) in the chemotherapy group. The OR rate reached 73% (11/15 cases) for sirolimus regardless of the treatment line. All patients archived disease control. Three patients died due to disease progression after 55, 32, and 32 months since metastatic disease diagnosis. After a median follow-up of 55.7 (range: 3.2-220) months, the 5 yr OS was 65% (CI 95% 39-100). Our study is the largest single-institution report on PEComa systemic targeted therapy and fills the gap in the field of advanced PEComa care since the FDA/EMEA approval of sirolimus.

A large bi-lobed classic renal angiomyolipoma with vena caval extension

Renal angiomyolipomas (AMLs) are the most common benign renal tumors encountered, and composed of 3 components: mature adipose tissues, smooth muscles, and blood vessels. Mostly asymptomatic and discovered incidentally, the classic type of AMLs rarely extend to involve great vessels. Radiological confirmation of such lesions is paramount for diagnosis and planned intervention. Management of AMLs is based on clinical presentation and varies from active surveillance to invasive surgical interventions. A case of sizeable classic AML with extension to inferior vena cava is presented here, with successful tumor resection performed after complete liver mobilization. A literature review and a summary of similar cases are also presented. A multidisciplinary approach is required for proper and precise radiological diagnosis to achieve an adequate surgical resection, which might sometimes be complicated and complex, as in this current case.

ODAE: Ontology-based systematic representation and analysis of drug adverse events and its usage in study of adverse events given different patient age and disease conditions

Background

Drug adverse events (AEs), or called adverse drug events (ADEs), are ranked one of the leading causes of mortality. The Ontology of Adverse Events (OAE) has been widely used for adverse event AE representation, standardization, and analysis. OAE-based ADE-specific ontologies, including ODNAE for drug-associated neuropathy-inducing AEs and OCVDAE for cardiovascular drug AEs, have also been developed and used. However, these ADE-specific ontologies do not consider the effects of other factors (e.g., age and drug-treated disease) on the outcomes of ADEs. With more ontological studies of ADEs, it is also critical to develop a general purpose ontology for representing ADEs for various types of drugs.

Results

Our survey of FDA drug package insert documents and other resources for 224 neuropathy-inducing drugs discovered that many drugs (e.g., sirolimus and linezolid) cause different AEs given patients’ age or the diseases treated by the drugs. To logically represent the complex relations among drug, drug ingredient and mechanism of action, AE, age, disease, and other related factors, an ontology design pattern was developed and applied to generate a community-driven open-source Ontology of Drug Adverse Events (ODAE). The ODAE development follows the OBO Foundry ontology development principles (e.g., openness and collaboration). Built on a generalizable ODAE design pattern and extending the OAE and NDF-RT ontology, ODAE has represented various AEs associated with the over 200 neuropathy-inducing drugs given different age and disease conditions. ODAE is now deposited in the Ontobee for browsing and queries. As a demonstration of usage, a SPARQL query of the ODAE knowledge base was developed to identify all the drugs having the mechanisms of ion channel interactions, the diseases treated with the drugs, and AEs after the treatment in adult patients. AE-specific drug class effects were also explored using ODAE and SPARQL.

Conclusion

ODAE provides a general representation of ADEs given different conditions and can be used for querying scientific questions. ODAE is also a robust knowledge base and platform for semantic and logic representation and study of ADEs of more drugs in the future.

Electronic supplementary material

The online version of this article (10.1186/s12859-019-2729-1) contains supplementary material, which is available to authorized users.

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.

Energy Stress-Mediated Cytotoxicity in Tuberous Sclerosis Complex 2-Deficient Cells with Nelfinavir and Mefloquine Treatment

To find new anti-cancer drug therapies, we wanted to exploit homeostatic vulnerabilities within Tuberous Sclerosis Complex 2 (TSC2)-deficient cells with mechanistic target of rapamycin complex 1 (mTORC1) hyperactivity. We show that nelfinavir and mefloquine synergize to selectively evoke a cytotoxic response in TSC2-deficient cell lines with mTORC1 hyperactivity. We optimize the concentrations of nelfinavir and mefloquine to a clinically viable range that kill cells that lack TSC2, while wild-type cells tolerate treatment. This new clinically viable drug combination causes a significant level of cell death in TSC2-deficient tumor spheroids. Furthermore, no cell recovery was apparent after drug withdrawal, revealing potent cytotoxicity. Transcriptional profiling by RNA sequencing of drug treated TSC2-deficient cells compared to wild-type cells suggested the cytotoxic mechanism of action, involving initial ER stress and an imbalance in energy homeostatic pathways. Further characterization revealed that supplementation with methyl pyruvate alleviated energy stress and reduced the cytotoxic effect, implicating energy deprivation as the trigger of cell death. This work underpins a critical vulnerability with cancer cells with aberrant signaling through the TSC2-mTORC1 pathway that lack flexibility in homeostatic pathways, which could be exploited with combined nelfinavir and mefloquine treatment.

Systems biology approach reveals a link between mTORC1 and G2/M DNA damage checkpoint recovery

Checkpoint recovery, the process that checkpoint-arrested cells with normal DNA repair capacity resume cell cycle progression, is essential for genome stability. However, the signaling network of the process has not been clearly defined. Here, we combine functional proteomics, mathematical modeling, and molecular biology to identify mTORC1, the nutrient signaling integrator, as the determinant for G2/M checkpoint recovery. Inhibition of the mTORC1 pathway delays mitotic entry after DNA damage through KDM4B-mediated regulation of CCNB1 and PLK1 transcription. Cells with hyper-mTORC1 activity caused by TSC2 depletion exhibit accelerated G2/M checkpoint recovery. Those Tsc2-null cells are sensitive to WEE1 inhibition in vitro and in vivo by driving unscheduled mitotic entry and inducing mitotic catastrophe. These results reveal that mTORC1 functions as a mediator between nutrition availability sensing and cell fate determination after DNA damage, suggesting that checkpoint inhibitors may be used to treat mTORC1-hyperactivated tumors such as those associated with tuberous sclerosis complex.

Genotype-phenotype correlation of patients with tuberous sclerosis complex-associated renal angiomyolipoma: a descriptive study

TSC2 gene mutation was repeatedly reported to be associated with a more severe phenotype in patients with tuberous sclerosis complex (TSC). Our current study aims to further explore whether there is such a correlation in patients with TSC-associated renal angiomyolipoma (TSC-RAML). TSC1/TSC2 gene mutation was screened by high-throughput sequencing in 25 TSC-RAML patients from 2 medical centers. Clinical data were also carefully collected. Linear regression analysis and Student t-test were conducted by IBM SPSS Statistics Version 21.0 to analyze the genotypic-phenotypic relationship. The results indicated a high level of TSC gene mutation (80%; 20/25) in TSC-RAML patients, with higher frequency of TSC2 mutation (68%; 17/25) than TSC1 mutation (12%; 3/25). Seven novel mutation sites were detected in this study. In general, there were no significant correlations between tumor size and age (r = 0.134, P = .522), hemoglobin (r = 0.255, P = .219), and serum creatinine (r = 0.043, P = .839). Patients with larger tumor size have higher risk of bleeding. Specially, it was higher hemoglobin level in patients with TSC1 mutation than ones with TSC2 mutation and without TSC mutation (P < .05). However, no difference was found in either tumor size or serum creatinine by TSC mutation genes (P > .05). Furthermore, no difference was found in tumor size, hemoglobin, and serum creatinine by TSC mutation types (P > .05). In conclusion, TSC-RAML is TSC2 mutation dominant, with the individual differences varying greatly. No definite genotype-phenotype correlation exists in patients with TSC-RAML, and it needs to be further explored.

Loss of tuberous sclerosis complex 2 sensitizes tumors to nelfinavir-bortezomib therapy to intensify endoplasmic reticulum stress-induced cell death

Cancer cells lose homeostatic flexibility because of mutations and dysregulated signaling pathways involved in maintaining homeostasis. Tuberous Sclerosis Complex 1 (TSC1) and TSC2 play a fundamental role in cell homeostasis, where signal transduction through TSC1/TSC2 is often compromised in cancer, leading to aberrant activation of mechanistic target of rapamycin complex 1 (mTORC1). mTORC1 hyperactivation increases the basal level of endoplasmic reticulum (ER) stress via an accumulation of unfolded protein, due to heightened de novo protein translation and repression of autophagy. We exploit this intrinsic vulnerability of tumor cells lacking TSC2, by treating with nelvinavir to further enhance ER stress while inhibiting the proteasome with bortezomib to prevent effective protein removal. We show that TSC2-deficient cells are highly dependent on the proteosomal degradation pathway for survival. Combined treatment with nelfinavir and bortezomib at clinically relevant drug concentrations show synergy in selectively killing TSC2-deficient cells with limited toxicity in control cells. This drug combination inhibited tumor formation in xenograft mouse models and patient-derived cell models of TSC and caused tumor spheroid death in 3D culture. Importantly, 3D culture assays differentiated between the cytostatic effects of the mTORC1 inhibitor, rapamycin, and the cytotoxic effects of the nelfinavir/bortezomib combination. Through RNA sequencing, we determined that nelfinavir and bortezomib tip the balance of ER protein homeostasis of the already ER-stressed TSC2-deficient cells in favor of cell death. These findings have clinical relevance in stratified medicine to treat tumors that have compromised signaling through TSC and are inflexible in their capacity to restore ER homeostasis.

The Risks of Renal Angiomyolipoma: Reviewing the Evidence

Renal angiomyolipoma (RAML), though a rare benign tumor, may impose a significant morbidity or even mortality due to its unique characteristics and the complications subsequent to its treatment. The classic tumor variant is composed of smooth muscular, vascular, and fatty components. The most straightforward diagnosis is when the fat component is abundant and gives a characteristic appearance on different imaging studies. In fat-poor lesions, however, the diagnosis is difficult and presumed a renal cell carcinoma. Yet, some variants of RAML, though rare, express an aggressive behavior leading to metastasis and mortality. The challenge lies in the early detection of benign variants and identifying aggressive lesions for proper management. Another challenge is when the vascular tissue component predominates and poses a risk of hemorrhage that may extend to the retroperitoneum in a massive life-threatening condition. The predicament here is to identify the characteristics of tumors at risk of bleeding and provide a prophylactic treatment. According to the clinical presentation, different treatment modalities, prophylactic or therapeutic, are available that span the spectrum of observation, embolization, or surgery. Renal impairment may result from extensive tumor burden or as a complication of the management itself. Improvement of diagnostic techniques, super-selective embolization, nephron-sparing surgery, and late treatment with the mammalian target of rapamycin inhibitors have provided more effective and safe management strategies. In this review, we examine the evidence pertaining to the risks imposed by RAML to the patients and identify merits and hazards associated with different treatment modalities.

Familial genetic tuberous sclerosis complex associated with bilateral giant renal angiomyolipoma: A case report

Tuberous sclerosis complex (TSC) is an autosomal dominant disease involving multiple organs, but there are a limited number of reports on family TSC. In the present report, a case of a 52-year-old female with a familial genetic TSC, associated with bilateral giant renal angiomyolipoma, was described. The mother, second elder brother and daughter of the patient all exhibited TSC, but the clinical manifestations, and therapeutic prognosis between the family members were not the same. The present case report aimed at identifying an effective diagnostic method and treatment through additional study of familial genetic TSC, in order to prolong and improve the quality of life for patients with TSC. According to the present case and relevant literature reviews, it is suggested that fetal gene detection during pregnancy could prevent the passing of this disease onto further generations. Furthermore, early application of drug treatment may control the development of the disease in diagnosed patients. The combination of classical treatments with a small dose of mammalian target of rapamycin inhibitors is the typical recommendation, which may control the development of the disease more effectively and decrease adverse side-effects.

Laparoscopic cryoablation of angiomyolipomas in adolescents and young adults: A report of four cases associated with tuberous sclerosis and 1 case of sporadic origin

INTRODUCTION

Renal angiomyolipomas (AMLs) can be of sporadic origin or associated with tuberous sclerosis (TS). TS-associated AMLs often present in childhood, tend to be bilateral and multiple, and often exhibit a faster growth rate with an increased risk of hemorrhage. Renal cryoablation is well described in adults, whereas experiences with adolescents and young adults are limited. We present here for the first time a series of renal AMLs within adolescents and young adults treated with laparoscopic assisted cryoablation (LCA).

OBJECTIVE

The aim was to evaluate whether LCA of AMLs in adolescents and young adults is a safe and feasible treatment modality.

STUDY DESIGN

From October 2009 to September 2013 a total of five patients at our institution were diagnosed with AMLs requiring treatment. Four patients had TS and one had AML of sporadic origin, all five patients underwent LCA. Data were retrospectively collected by a systematic review of patient material and reassessment of renal imaging.

RESULTS

The median age was 16 years (range 13-27 years). Eight AMLs with a median size of 3.9 cm (range 2.1-7.7 cm) were treated in five patients because of tumor size and rapid growth. Follow-up was a median 37 months (range 20-62 months), and all tumors showed a reduction in tumor size, and no regrowth was recognized (see summary table). The procedure was well tolerated, with only few perioperative complications and no postoperative complications.

DISCUSSION

When considering the indication for treating AMLs, the origin (sporadic or TS associated) and size of the tumor are the decisive factors. To preserve renal function and prevent spontaneous hemorrhage caution should be intensified when tumors reach 4 cm, particularly if TS is present. After the diagnosis is established, patients should be monitored with renal imaging at regular intervals to identify rapid-growing tumors. As an alternative to current treatment modalities such as partial nephrectomy and super selective angioembolization, cryoablation is an emerging approach, although experience with pediatric patients is limited. For patients not requiring immediate surgery, pharmacological treatment with mTOR inhibitors is now being evaluated as an alternative treatment option or as neo-adjuvant therapy to ablative techniques.

CONCLUSION

Prophylactic treatment of large or rapid growing AMLs with LCA appears to be a safe and feasible nephron-sparing approach in adolescents and young adults. The low perioperative complication rate and promising effect on outcome might allow treatment of subclinical AMLs in order to minimize the risk of potentially life-threatening complications and preserve renal function.

Coexistence of pulmonary lymphangioleiomyomatosis and pulmonary angiomyolipoma

Background

Lymphangioleiomyomatosis (LAM) and angiomyolipoma are two different, but related rare diseases. To the best of our knowledge, pulmonary LAM and pulmonary angiomyolipoma have not previously been observed in the same patient.

Case presentation

A 38-year-old woman presented with a dry cough and left flank pain. She had a right nephrectomy for renal angiomyolipoma 17 years ago. A magnetic resonance imaging scan demonstrated a round mass in the left kidney. A chest computed tomography scan demonstrated scattered small thin-walled cysts and multifocal round nodules in both lungs. A lung biopsy via video-assisted thoracoscopic surgery revealed that the cysts and nodules were manifestations of LAM and angiomyolipomas, respectively. After sirolimus therapy, the renal angiomyolipoma and metastasized pulmonary angiomyolipomas shrank, but pulmonary cysts were unchanged.

Conclusions

LAM and angiomyolipoma are significantly associated, and may coexist in the lungs in rare cases. Sirolimus is effective for both renal angiomyolipoma and metastasized pulmonary angiomyolipomas.

Evidence Supporting a Lymphatic Endothelium Origin for Angiomyolipoma, a TSC2(-) Tumor Related to Lymphangioleiomyomatosis

Angiomyolipoma (AML) is a tumor closely related to lymphangioleiomyomatosis (LAM). Both entities are characterized by the proliferation of smooth muscle actin and melanocytic glycoprotein 100 (recognized by antibody HMB-45)-positive spindle-shaped and epithelioid cells. AML and LAM are etiologically linked to mutations in the tsc2 and tsc1 genes in the case of LAM. These genes encode the proteins tuberous sclerosis complex (TSC)-1 and TSC2, which are directly involved in suppressing the mechanistic target of rapamycin cell growth signaling pathway. Although significant progress has been made in characterizing and pharmacologically slowing the progression of AML and LAM with rapamycin, our understanding of their pathogenesis lacks an identified cell of origin. We used an AML-derived cell line to determine whether TSC2 restitution brings about the cell type from which AML arises. We found that AML cells express lymphatic endothelial cell markers consistent with lymphatic endothelial cell precursors in vivo and in vitro. Moreover, on TSC2 correction, AML cells mature into adult lymphatic endothelial cells and have functional attributes characteristic of this cell lineage, suggesting a lymphatic endothelial cell of origin for AML. These effects are dependent on TSC2-mediated mechanistic target of rapamycin inactivation. Finally, we demonstrate the in vitro effectiveness of norcantharidin, a lymphangiogenesis inhibitor, as a potential co-adjuvant therapy in the treatment of AML.

Four-week rapamycin treatment improves muscular dystrophy in a fukutin-deficient mouse model of dystroglycanopathy

Background

Secondary dystroglycanopathies are a subset of muscular dystrophy caused by abnormal glycosylation of α-dystroglycan (αDG). Loss of αDG functional glycosylation prevents it from binding to laminin and other extracellular matrix receptors, causing muscular dystrophy. Mutations in a number of genes, including FKTN (fukutin), disrupt αDG glycosylation.

Methods

We analyzed conditional Fktn knockout (Fktn KO) muscle for levels of mTOR signaling pathway proteins by Western blot. Two cohorts of Myf5-cre/Fktn KO mice were treated with the mammalian target of rapamycin (mTOR) inhibitor rapamycin (RAPA) for 4 weeks and evaluated for changes in functional and histopathological features.

Results

Muscle from 17- to 25-week-old fukutin-deficient mice has activated mTOR signaling. However, in tamoxifen-inducible Fktn KO mice, factors related to Akt/mTOR signaling were unchanged before the onset of dystrophic pathology, suggesting that Akt/mTOR signaling pathway abnormalities occur after the onset of disease pathology and are not causative in early dystroglycanopathy development. To determine any pharmacological benefit of targeting mTOR signaling, we administered RAPA daily for 4 weeks to Myf5/Fktn KO mice to inhibit mTORC1. RAPA treatment reduced fibrosis, inflammation, activity-induced damage, and central nucleation, and increased muscle fiber size in Myf5/Fktn KO mice compared to controls. RAPA-treated KO mice also produced significantly higher torque at the conclusion of dosing.

Conclusions

These findings validate a misregulation of mTOR signaling in dystrophic dystroglycanopathy skeletal muscle and suggest that such signaling molecules may be relevant targets to delay and/or reduce disease burden in dystrophic patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13395-016-0091-9) contains supplementary material, which is available to authorized users.

Advances in Tuberous Sclerosis Complex (TSC) research

Purpose

– The purpose of this paper is to provide a brief, descriptive overview of Tuberous Sclerosis Complex (TSC) research with particular reference to studies on Autism Spectrum Disorder (ASD).

Design/methodology/approach

– A search of electronic databases was carried out to identify English language articles on TSC. The literature was explored in more detail with a focus on neurodevelopmental disorders associated with TSC such as ASD.

Findings

– The review included 3,679 references. The earliest articles identified were published in the early twentieth century. Since then research on TSC has advanced rapidly and is being carried out worldwide. Just 62 studies have focused on ASD in TSC, although the number of publications is increasing over time.

Research limitations/implications

– More research on ASD in TSC is needed to benefit those affected by TSC and the broader ASD scientific community.

Practical implications

– Practitioners working with children and adults with ASD should be aware of the wider health issues experienced by those with genetic conditions such as TSC. Similarly, clinicians working with those who have TSC should be aware of the high prevalence of ASD in the group and implications for the way they work with their patients.

Originality/value

– This is the first paper to map and characterise the scientific literature on TSC. There remains a focus on the biomedical aspects of TSC with fewer studies on psychosocial/educational or family impacts. The review concludes with recommended research questions for the future.

Angiographic and volumetric effects of mammalian target of rapamycin inhibitors on angiomyolipomas in tuberous sclerosis

AIM: To investigate the angiographic and volumetric effects of mammalian target of rapamycin (mTOR) inhibitors on angiomyolipomas (AMLs) in a case series of patients with tuberous sclerosis complex.

METHODS: All patients who underwent catheter angiography prior to and following mTOR inhibitor therapy (n = 3) were evaluated. All cross-sectional imaging studies were analyzed with three-dimensional volumetrics, and tumor volume curves for all three tissue compartments (soft tissue, vascular, and fat) were generated. Segmentation analysis tools were used to automatically create a region of interest (ROI) circumscribing the AML. On magnetic resonance images, the “fat only” map calculated from the in- and opposed-phase gradient recalled echo sequences was used to quantify fat volume within tumors. Tumor vascularity was measured by applying a thresholding tool within the ROI on post-contrast subtraction images. On computed tomography images, volume histogram analysis of Hounsfield unit was performed to quantify tumor tissue composition. The angiography procedures were also reviewed, and tumor vascularity based on pre-embolization angiography was characterized in a semi-quantitative manner.

RESULTS: Patient 1 presented at the age of 15 with a 6.8 cm right lower pole AML and a 4.0 cm right upper pole AML. Embolization was performed of both tumors, and after a few years of size control, the tumors began to grow, and the patient was initiated on mTOR inhibitor therapy. There was an immediate reduction in the size of both lesions. The patient then underwent repeat embolization and discontinuation of mTOR inhibition, after which point there was a substantial regrowth in both tumors across all tissue compartments. Patient 2 presented at the age of 18 with a right renal AML. Following a brief period of tumor reduction after embolization, she was initiated on mTOR inhibitor therapy, with successful reduction in tumor size across all tissue compartments. As with patient 1, however, there was immediate rebound growth following discontinuation of inhibitor therapy, without sustained control despite repeat embolization. patient 3 presented at the age of 5 with a left renal AML and underwent two embolization procedures without lasting effect prior to starting mTOR inhibition. As with patients 1 and 2, following discontinuation of therapy, there was immediate rebound growth of the tumor. Repeat embolization, however, was notable for a substantial reduction in intratumoral aneurysms and vascularity.

CONCLUSION: AML volume reduction as well as post-treatment rebound growth due to mTOR inhibitors involves all three tissue components of the tumor.

Pulmonary choriostoma in a case of tuberous sclerosis complex

A 52 years old lady was diagnosed to have Tuberous Sclerosis Complex (TSC) on the basis of 2 major and one minor criterion. She had family history of similar complaints in her sister and two sons. There was involvement of kidney in the form of angiomyolipoma, skin in the form of facial angiofibroma and teeth with a dental pit. She had an unusual lung involvement in the form of multiple small choristomas. Choristoma was diagnosed on transbronchial lung biopsy and was present in the form of disorganised striated muscles. The reported pulmonary manifestations of TCS i.e. lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH) are types of hamartomas. Hamartomas and choristomas are both types of disorganized tissue. ‘Choristoma’of lung in TSC however is not reported. Clinopathological correlation of pulmonary hamartoma and choristoma, and treatment in TSC has been discussed.

Spontaneous rupture of a giant renal angiomyolipoma-Wunderlich's syndrome: Report of a case

INTRODUCTION

Herein we present a rare case of pontaneous rupture of a giant renal angiomyolipoma (AML), with symptoms of hypovolemic shock (Wunderlich's syndrome), which was managed by urgent total nephrectomy.

PRESENTATION OF CASE

A 53 year old female was transferred to the emergency room with progressive acute painful swelling of the left lateral abdominal area, duration of 5h. An emergent ultrasonic examination, revealed a heterogeneous-solid mass with maximum diameter of 23cm, with probable origin from the left kidney. Due to worsening of the clinical status (hypovolemic shock), loss of consciousness and acute drop of haematocrit level to 17.8%, the patient was urgently intubated in the emergency room and transferred to the operating theater. A giant haemorrhagic mass was found originating from the left kidney, which removed en-block with the left kidney. The patient was transferred to the intensive care unit. Her recovery was uneventful. The histopathologic examination revealed a giant renal angiomyolipoma (25×18×8cm) with extensive bleeding.

DISCUSSION

Enlarged renal AMLs can rupture. This can be sudden and painful with manifestations of hypovolemic shock. The management of AMLs has been correlated with symptoms. Patients with life-threatening retroperitoneal haemorrhage, require urgent exploration as retroperitoneal bleeding can lead to severe complications, increasing morbidity.

CONCLUSION

In case of giant angiomyolipoma with intratumoral haemorrhage, and symptoms of Wunderlich's syndrome, partial or total nephrectomy is a good treatment option in order to save the patient's life.

Update on the Diagnosis and Management of Renal Angiomyolipoma

PURPOSE

Advances in minimally invasive therapies and novel targeted chemotherapeutics have provided a breadth of options for the management of renal masses. Management of renal angiomyolipoma has not been reviewed in a comprehensive fashion in more than a decade. We provide an updated review of the current diagnosis and management strategies for renal angiomyolipoma.

MATERIALS AND METHODS

We conducted a PubMed(®) search of all available literature for renal or kidney angiomyolipoma. Further sources were identified in the reference lists of identified articles. We specifically reviewed case series of partial nephrectomy, selective arterial embolization and ablative therapies as well as trials of mTOR inhibitors for angiomyolipoma from 1999 to 2014.

RESULTS

Renal angiomyolipoma is an uncommon benign renal tumor. Although associated with tuberous sclerosis complex, these tumors occur sporadically. Risk of life threatening hemorrhage is the main clinical concern. Due to the fat content, angiomyolipomas are generally readily identifiable on computerized tomography and magnetic resonance imaging. However, fat poor angiomyolipoma can present a diagnostic challenge. Novel research suggests that various strategies using magnetic resonance imaging, including chemical shift magnetic resonance imaging, have the potential to differentiate fat poor angiomyolipoma from renal cell carcinoma. Active surveillance is the accepted management for small asymptomatic masses. Generally, symptomatic masses and masses greater than 4 cm should be treated. However, other relative indications may apply. Options for treatment have traditionally included radical and partial nephrectomy, selective arterial embolization and ablative therapies, including cryoablation and radio frequency ablation, all of which we review and update. We also review recent advances in the medical treatment of patients with tuberous sclerosis complex associated angiomyolipomas with mTOR inhibitors. Specifically trials of everolimus for patients with tuberous sclerosis complex suggest that this agent may be safe and effective in treating angiomyolipoma tumor burden. A schema for the suggested management of renal angiomyolipoma is provided.

CONCLUSIONS

Appropriately selected cases of renal angiomyolipoma can be managed by active surveillance. For those patients requiring treatment nephron sparing approaches, including partial nephrectomy and selective arterial embolization, are preferred options. For those with tuberous sclerosis complex mTOR inhibitors may represent a viable approach to control tumor burden while conserving renal parenchyma.

Inhibition of Angiofibromas in a Tuberous Sclerosis Patient Using Topical Timolol 0.5% Gel

Angiofibromas are the most recognized cutaneous manifestations of tuberous sclerosis complex. Angiofibromas can be associated with disfigurement, bleeding, pruritus, and erythema and may lead to significant psychosocial consequences for affected patients. Histopathologically, angiofibromas consist of a mixture of vascular and interstitial cells. Traditional treatment options include cryotherapy, electrocoagulation, radiofrequency ablation, dermabrasion, laser treatment, and topical agents such as podophyllotoxin. However, complications such as pain, postinflammatory hyperpigmentation, scarring, and the frequent recurrence rate reduce the utility of these treatment options. The introduction of topical rapamycin marked a turning point for treatment of facial angiofibromas; however, the lack of a standardized formulation, limited insurance coverage, and significant financial cost restrict universal access for patients and their caregivers. Both oral and topical β-blockers have proven extremely effective treatments for superficial vascular tumors such as hemangiomas and pyogenic granulomas. Topical β-blockers may potentially be useful for treatment of angiofibromas considering these lesions also contain a vascular component. Here we present an exploratory case report of a patient with tuberous sclerosis complex who had significant clinical improvement of her facial angiofibromas utilizing a "split-face" comparison protocol of topical timolol 0.5% gel after full-field treatment with ablative fractional laser resurfacing and pulsed-dye laser.

Rapamycin and chloroquine: the in vitro and in vivo effects of autophagy-modifying drugs show promising results in valosin containing protein multisystem proteinopathy

Mutations in the valosin containing protein (VCP) gene cause hereditary Inclusion body myopathy (hIBM) associated with Paget disease of bone (PDB), frontotemporal dementia (FTD), more recently termed multisystem proteinopathy (MSP). Affected individuals exhibit scapular winging and die from progressive muscle weakness, and cardiac and respiratory failure, typically in their 40s to 50s. Histologically, patients show the presence of rimmed vacuoles and TAR DNA-binding protein 43 (TDP-43)-positive large ubiquitinated inclusion bodies in the muscles. We have generated a VCP^R155H/+ mouse model which recapitulates the disease phenotype and impaired autophagy typically observed in patients with VCP disease. Autophagy-modifying agents, such as rapamycin and chloroquine, at pharmacological doses have previously shown to alter the autophagic flux. Herein, we report results of administration of rapamycin, a specific inhibitor of the mechanistic target of rapamycin (mTOR) signaling pathway, and chloroquine, a lysosomal inhibitor which reverses autophagy by accumulating in lysosomes, responsible for blocking autophagy in 20-month old VCP^R155H/+ mice. Rapamycin-treated mice demonstrated significant improvement in muscle performance, quadriceps histological analysis, and rescue of ubiquitin, and TDP-43 pathology and defective autophagy as indicated by decreased protein expression levels of LC3-I/II, p62/SQSTM1, optineurin and inhibiting the mTORC1 substrates. Conversely, chloroquine-treated VCP^R155H/+ mice revealed progressive muscle weakness, cytoplasmic accumulation of TDP-43, ubiquitin-positive inclusion bodies and increased LC3-I/II, p62/SQSTM1, and optineurin expression levels. Our in vitro patient myoblasts studies treated with rapamycin demonstrated an overall improvement in the autophagy markers. Targeting the mTOR pathway ameliorates an increasing list of disorders, and these findings suggest that VCP disease and related neurodegenerative multisystem proteinopathies can now be included as disorders that can potentially be ameliorated by rapalogs.

Pulmonary lymphangioleiomyomatosis: analysis of disease manifestation by region-based quantification of lung parenchyma

PURPOSE

Lymphangioleiomyomatosis (LAM) is characterized by proliferation of smooth muscle tissue that causes bronchial obstruction and secondary cystic destruction of lung parenchyma. The aim of this study was to evaluate the typical distribution of cystic defects in LAM with quantitative volumetric chest computed tomography (CT).

MATERIALS AND METHODS

CT examinations of 20 patients with confirmed LAM were evaluated with region-based quantification of lung parenchyma. Additionally, 10 consecutive patients were identified who had recently undergone CT imaging of the lung at our institution, in which no pathologies of the lung were found, to serve as a control group. Each lung was divided into three regions (upper, middle and lower thirds) with identical number of slices. In addition, we defined a "peel" and "core" of the lung comprising the 2 cm subpleural space and the remaining inner lung area. Computerized detection of lung volume and relative emphysema was performed with the PULMO 3D software (v3.42, Fraunhofer MEVIS, Bremen, Germany). This software package enables the quantification of emphysematous lung parenchyma by calculating the pixel index, which is defined as the ratio of lung voxels with a density <-950HU to the total number of voxels in the lung.

RESULTS

Cystic changes accounted for 0.1-39.1% of the total lung volume in patients with LAM. Disease manifestation in the central lung was significantly higher than in peripheral areas (peel median: 15.1%, core median: 20.5%; p=0.001). Lower thirds of lung parenchyma showed significantly less cystic changes than upper and middle lung areas combined (lower third: median 13.4, upper and middle thirds: median 19.0, p=0.001).

CONCLUSION

The distribution of cystic lesions in LAM is significantly more pronounced in the central lung compared to peripheral areas. There is a significant predominance of cystic changes in apical and intermediate lung zones compared to the lung bases.