Acute haemorrhage from a large renal epithelioid angiomyolipoma: diagnostic and management considerations in a teenage patient with a rare cancer

Acute renal haemorrhage is a life-threatening condition that is complicated in the context of renal malignancy. Here, we present the case of a teenage male presenting acutely with a large, bleeding renal epithelioid angiomyolipoma (EAML) of the kidney-a rare cancer, which is part of the perivascular epithelioid cell tumour family. The patient was managed acutely with prompt resuscitation, transfer to a centre of expertise and haemorrhagic control using radiologically guided endovascular techniques; this subsequently permitted an oncologically sound procedure (radical nephrectomy, inferior vena cava thrombectomy and lymphadenectomy) to be performed within 24 hours. The description and discussion around this unique case summarises the patient's clinical journey, while exploring the current literature surrounding diagnosis and outcomes of patients with renal EAMLs.

Tuberous Sclerosis Complex (TSC): Renal and Extrarenal Imaging

Tuberous sclerosis complex is a multiorgan syndrome manifesting with several benign and malignant tumors. Complications arising from renal abnormalities are a leading cause of death in patients with tuberous sclerosis complex. Renal cell carcinoma is relatively uncommon, occurring in 2%-4% of patients with tuberous sclerosis complex syndrome, but nonetheless can significantly contribute to morbidity and mortality. Extrarenal manifestations of tuberous sclerosis complex, including within the chest, abdomen and central nervous system, aid in diagnosis. Pathogenesis and management are also discussed, including the importance of the types of renal masses found in these patients.

Clinical and pathological features of renal epithelioid angiomyolipoma (PEComa): A single institution series

Renal angiomyolipomas are benign tumors of the kidney that belong to the 'PEComa: perivascular epithelioid cell' family. Epithelioid AMLs (eAML) are a rare monotypic subtype with malignant potential, that can occur sporadically or be associated with tuberous sclerosis (TSC). Due to their epithelioid nature, eAMLs can closely resemble high-grade renal cell carcinoma (RCC), which may result in misdiagnosis. Multiple clinicopathologic parameters are predictive of worse outcomes for patients with eAML. Those can be used to stratify patients into groups with low, intermediate and high risk for disease progression. A high index of suspicion and a thorough immunohistochemical study are required to correctly diagnose eAML. Radiographically, eAMLs are also a diagnostic challenge as they share features with RCC on CT and MR imaging. Due to this close mimicry, the true incidence of eAML is thought to be much higher than 200 cases as reported in the literature. We report a series of four patients diagnosed with eAML and compare their clinical courses. We also report on the successful treatment of a patient with pulmonary metastasis from eAML using the mTOR inhibitor, everolimus. By identifying eAML and recognizing its high-risk features, it is possible mTOR inhibitors may have a meaningful role in the adjuvant treatment of these patients.

Renal angiomyolipoma and tuberous sclerosis complex: long-term safety and efficacy outcomes of Everolimus therapy

INTRODUCTION

Renal angiomyolipoma is a frequent manifestation of Tuberous Sclerosis Complex (TSC), for which everolimus therapy has been recently established as a novel non-invasive therapeutic option. As there are limited real life and long-term data, the analysis of our experience provides added value in terms of safety and efficacy.

MATERIAL AND METHODS

Descriptive analysis of our experience in patients with giant bilateral renal angiomyolipomas, in the context of TSC, treated with 10 mg oral everolimus daily, during a median of 71.5 months. We evaluated the following parameters: response rate and duration, reduction of kidney size and lesions, prevention of complications and presentation of toxicity and its cause.

RESULTS

We confirm the effectiveness of treatment in 4 young patients, with multiple, bilateral angiomyolipomas of a median of 12 (5-19) cm maximum diameter, from June 2013 to date, after continuous reduction in lesion size, a decrease of 30% of the volume in 75% at six months and 50% in half of the subjects at two years, still showing drug response. Absence of complications such as bleeding or glomerular filtration rate decline in the long term, with a favorable safety profile, without interruptions and with mild-moderate, non-cumulative adverse effects, mostly within the first year of treatment.

CONCLUSION

Everolimus is a safe and effective therapeutic option for renal angiomyolipoma and various manifestations of TSC, which has been reproduced in real life with six years of follow-up.

Everolimus in Invasive Malignant Renal Epithelioid Angiomyolipoma

Background

To evaluate the efficacy and safety of everolimus, a mTOR inhibitor, on invasive malignant renal epithelioid angiomyolipoma (EAML).

Materials and Methods

From Oct 2014 to May 2019, we collected data from seven patients with a definite (clinical and pathological) diagnosis of EAML received everolimus in our hospital. Targeted sequence capture array technique with next-generation of high throughput sequencing (NGS) were performed to detect mutations of TSC1/2 genes. All patients had received surgery and everolimus. The clinical efficacy and safety of the therapy were evaluated.

Results

Mutations of TSC1 and TSC2 were detected in two and three patients though targeted sequence capture array technique with NGS, respectively. Among seven patients, three had missense mutations, one had nonsense mutation, and one had the large fragment deletion mutation. Five patients accompanied with tuberous sclerosis complex (TSC) were identified. All patients were administered 10mg everolimus once daily, the treatment duration lasted for 3 to 28 months. The objective response was assessed 3 months later, five partial response, two stable disease (SD), the mean greatest tumor diameter of all patients decreased from 9.6 to 5.2cm. Six patients stayed SD and one patient died during follow up. Patients accompanying with TSC had better responses to everolimus compared with non-TSC.

Conclusion

The mTOR inhibitor can be an effective treatment for patients with invasive malignant renal EAML. Patients with TSC may benefit more from the therapy.

Metastatic epithelioid angiomyolipoma treated with everolimus in a patient receiving hemodialysis: A case report

Introduction

A patient undergoing hemodialysis and being treated with everolimus for metastatic epithelioid angiomyolipoma has never been described in the literature, to our knowledge.

Case presentation

A 53‐year‐old woman who had undergone trans‐arterial embolization for epithelioid angiomyolipoma was referred with a chief complaint about right knee pain. Hemodialysis had been started after the embolization. Needle biopsy specimens of tumors obtained from behind the right kidney and in the right femur were diagnosed as epithelioid angiomyolipoma metastases. The patient underwent treatment with everolimus and achieved a partial response after 6 months of treatment without serious adverse events.

Conclusion

Everolimus might be effective for patients with metastatic epithelioid angiomyolipoma who are undergoing hemodialysis.

Partial nephrectomy can be a successful treatment option for renal epithelioid angiomyolipoma: a case report and literature review

Background

Renal epithelioid angiomyolipoma is a rare tumour which involves kidneys in most cases. It is known for its aggressive behaviour as a significant number of cases have been associated with metastatic epithelioid angiomyolipoma. Usually, radical treatment with systemic therapy is recommended. Only a small number of cases of epithelioid angiomyolipomas have been reported with the standard treatment being radical or partial nephrectomy. We present a  case report showing that partial nephrectomy can be a successful treatment option for renal epithelioid angiomyolipoma. This is the first case of this nature in Lithuania.

Case presentation

In this case, a 40-year-old male with epithelioid angiomyolipoma of the left kidney is presented. In 2012, a cystic left renal mass 40 × 41 mm in size was diagnosed incidentally while performing ultrasound and later confirmed by MRI. Due to the size of the tumour and the possibility of renal cell carcinoma, surgery was scheduled. Left partial nephrectomy was performed successfully. Final pathology report came back with the diagnosis of renal epithelioid angiomyolipoma. The patient had yearly follow-up for six years by CT scan, and neither recurrence nor progression were observed.

Conclusions

Early detection and diagnosis are crucial for treatment as the tumour tends to have malignancy potential. With early diagnosis, partial nephrectomy can be performed with yearly follow-up and no systemic treatment required.

Sporadic Angiomyolipomas Growth Kinetics While on Everolimus: Results of a Phase II Trial

PURPOSE

Everolimus decreases tumor volume of renal angiomyolipomas in patients with tuberous sclerosis. No prospective data are available regarding the effect of everolimus on the growth kinetics in patients with sporadic angiomyolipomas. We sought to determine the safety and efficacy of everolimus in the volumetric reduction of sporadic angiomyolipomas.

MATERIALS AND METHODS

This multi-institutional, prospective, phase II trial, enrolled patients with 3 cm or larger sporadic angiomyolipomas who were candidates for surgical resection or percutaneous angioembolization. Patients received 10 mg everolimus daily for 4 planned 28-day cycles. Response was defined as a 25% or greater volumetric reduction of patient angiomyolipoma. Baseline, 4, 6 and 12-month volumetric analyses were performed using magnetic resonance imaging. Everolimus was discontinued in those with less than 25% volumetric reduction after 4 cycles. Those with 25% or greater volumetric reduction received 2 additional cycles. The primary outcomes were the efficacy of everolimus in the volumetric reduction of angiomyolipomas by 25% or more, and the safety and tolerability of everolimus.

RESULTS

Overall 20 patients were enrolled at 5 centers. Of these patients 11 (55%) completed 4 cycles and 7 (35%) completed 6 cycles. Efficacy was demonstrated, with 10 of 18 (55.6%) patients exhibiting a 25% or greater reduction in tumor volume at 4 months (median 58.5%) and 10 of 14 (71.4%) patients exhibiting a 25% or greater reduction in tumor volume at 6 months (median 58.2%). Four (20%) patients were withdrawn due to protocol defined toxicities and 8 (40%) self-withdrew from the study due to side effects.

CONCLUSIONS

Everolimus was effective in causing volumetric reduction of angiomyolipomas by 25% or greater in most patients but was associated with a high rate of treatment discontinuation.

Clinicopathologic analysis of renal epithelioid angiomyolipoma: Consecutively excised 23 cases

Renal epithelioid angiomyolipoma (eAML) is considered a malignant variant of angiomyolipoma (AML). From 2001 to 2016, a total of 570 patients were diagnosed with renal AML in Linko Chang Gung Memorial Hospital, Taiwan, including 23 cases of renal eAML. All 23 eAML cases were made up of at least 10% of epithelioid cells histologically. Three of these cases were found with multiple tumors. Two cases developed distant metastasis: one had mediastinal lymph nodes and bilateral lung metastasis; the other one had tumor recurrence over liver and retroperitoneum 1 year after radical nephrectomy. They were then divided into invasive (n = 5) and noninvasive (n = 18) groups according to their clinical behavior. The invasive group showed more severe nuclear atypia and higher rates in tumor necrosis. There was statistically no significance in relation to a patient's age, tumor size, and mitotic count between two groups. After conducting a series of studies, we suggest treating eAML with the guideline of renal cell carcinoma.

First-Line Therapy for Metastatic Soft Tissue Sarcoma

OPINION STATEMENT

Soft tissue sarcomas are rare cancers with an expected incidence of about 14,000 new cases in 2018, and account for less than 1% of all cancers. It includes in excess of 75 heterogeneous subtypes with varying biology, molecular aberrations, and variable response to treatment. Because of the rarity of these tumors and the many different subtypes, there is no large-scale data to guide treatment, and hence the need for a multidisciplinary individualized approach to treatment, preferably at a high-volume tertiary referral center. For localized disease, surgery with or without radiation is the preferred treatment. In metastatic disease, the longest track record is with use of anthracyclines, either alone or in combination with ifosfamide, but the median overall survival even with combination was just over a year. There have been recent advances in understanding the heterogeneity of these tumors and the need for an individualized approach. With that new knowledge, recent approvals of trabectedin, eribulin, and pazopanib have been limited to some select histologic subtypes with improved outcomes. More recently, immunotherapy has been tested in select histotypes of sarcoma with encouraging activity and has led to further evaluation in combination with immunotherapeutic agents, as well as with chemotherapy and radiation treatments. Here, in this article, we summarize the data of the currently approved therapies in metastatic soft tissue sarcoma, with the principal focus on first-line therapies. We also review the recent encouraging data with PDGFR-targeted antibody (olaratumab) with doxorubicin which showed an impressive improvement in overall survival in phase II study. Molecular characterization of sarcoma subtypes will likely improve understanding of these very diverse tumors and improve target characterization. The ongoing efforts in better understanding these rare tumors hold the key to make a difference in the outcome of these patients.

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.

Case report of everolimus-induced sustained partial response in metastatic renal epithelioid angiomyolipoma

Epithelioid variant of angiomyolipoma (EAML) is a newly defined entity and a close mimicker of renal cell carcinoma. There is a growing body of evidence to suggest its aggressive behavior in terms of local recurrence, metastasis and death. The treatment for this subset of patients has posed challenges for the experts. Chemotherapy plays little active role and so molecular profiling to identify genomic alterations amenable to targeted therapies has paved the way. Recently, tyrosine kinase inhibitors and mTOR inhibitors have been utilised both in adjuvant and neoadjuvant settings and have shown promising results in terms of survival. We present a case of a metastatic epithelioid angiomyolipoma treated sequentially with imatinib, crizotinib and now maintaining a sustained partial response with everolimus.

Renal epithelioid angiomyolipoma: magnetic resonance imaging characteristics

OBJECTIVE

The aim of the study was to analyze MR imaging features of renal epithelioid angiomyolipoma (EAML).

METHODS

This study included 17 patients with histopathologically confirmed renal EAML who underwent renal MRI scanning before radical or partial nephrectomy. MR images were retrospectively reviewed and correlated with pathological findings.

RESULT

Fifteen lesions (88.2%) appeared as round or oval. The tumor-kidney interface was round in 14 lesions (82.4%). Fifteen tumors (88.2%) presented mainly isointensity on T1WI, and eleven tumors (64.7%) presented mainly hypointensity on T2WI. Twelve lesions (70.6%) showed restricted diffusion on DWI, and the mean ADC value was 1.23 ± 0.28 × 10^-3mm²/s. Minimal fat component was identified as loss of signal intensity on opposed-phase MR images in 6 cases (35.3%). Sixteen lesions (100%) demonstrated inhomogeneous enhancement, and 7 of 16 masses (43.8%) showed reticular enhancement. Rapid wash-in and wash-out enhancement was seen in 13 masses (81.3%). In the corticomedullary phase, the mass showed markedly enhancement in 14 cases (87.5%). The irregular vessels and hemorrhage were detected in 4 cases (23.5%) and 7 cases (41.2%), respectively. One patient (5.9%) had a lymph node involvement at initial diagnosis, and showed distant metastasis after operation. In the immunohistochemical analysis, 15 tumors (88.2%) were positive for melanocytic marker (HMB45 or Melan-A), and all cases (100%) were negative for epithelial-associated markers (CK or AE1/AE3).

CONCLUSION

The presence of hypointensity on T2WI, restricted diffusion on DWI, round tumor-kidney interface, reticular, and marked enhancement (rapid wash-in and wash-out) should further raise suspicion for renal EAML. The diagnosis may be confirmed by pathological analysis.

Advanced sporadic renal epithelioid angiomyolipoma: case report of an extraordinary response to sirolimus linked to TSC2 mutation

Background

Renal epithelioid angiomyolipomas (EAML) are rare tumors with aggressive behavior. EAML can be sporadic or develop within the tuberous sclerosis complex syndrome, where mutations of TSC1 or TSC2 genes (critical negative regulators of mTOR Complex 1) result in an increased activation of mTOR pathway. Optimal EAML treatment, including mTOR inhibitors, remains undetermined.

Case presentation

Here we present the case of a young adult with a renal EAML that after radical nephrectomy developed metastases, first in liver and then in lumbar vertebrae. After complete surgical resection of these lesions, liver recurrence was detected, this time with incomplete surgical resection. After finding a new liver lesion, systemic treatment with sirolimus started. The patient exhibited a complete and durable response to this drug, being disease free at the time of publication, after 36 months of treatment. Targeted next generation sequencing (NGS) of MTOR, TSC1 and TSC2 genes in the primary tumor, metastasis and blood of the patient, revealed one inactivating TSC2 mutation (c.2739dup; p.K914*) in the tumor cells. Immunohistochemistry revealed decreased TSC2 protein content and increased phospho-S6 in the tumor cells, demonstrating mTOR pathway activation.

Conclusion

NGS on an EAML patient with an extraordinary response to sirolimus uncovered TSC2 inactivation as the mechanism for the response. This study supports NGS as a useful tool to identify patients sensitive to mTOR inhibitors and supports the treatment of malignant EAML with these drugs.

Primary pancreatic perivascular epithelioid cell tumor (PEComa): A surgical enigma. A systematic review of the literature

BACKGROUND

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor, with distinctive morphology and expression of myo-melanocytic markers. Current scientific literature reported just 24 cases of pancreatic PEComas. With our systematic review, we aimed at improving our understanding of the disease, focusing on the knowledge gained on epidemiology, etiology, clinical presentation, diagnosis, treatment and prognosis.

METHODS

Based on the PRISMA guidelines, a systematic research was carried out on PubMed/MEDLINE, Web of Science, Scopus, EMBASE, and EBSCO using the search terms: ("perivascular epithelioid cell tumor" OR ″PEComa") and ("pancreas "OR″ pancreatic").

RESULTS

The 4th-6th decades of life and female sex (86.9%) turned out as the most affected. Pancreatic head was the most involved site (50%), with a single lesion in almost all cases. The diagnosis was only obtained after histopathological examination (70.8%). The clinical presentation was non-specific, abdominal pain being the main symptom (60.9%). At immunohistochemistry, PEComa showed benign epithelioid predominance and a strong positivity for HMB-45, Melan-A, and α-SMA. Surgical resection was performed in almost all cases, while for one patient the multidisciplinary group chose just endoscopic and imaging follow-up, based on the benign nature of the lesion.

CONCLUSIONS

The biological characteristics of pancreatic PEComa remain an enigma. Its prognosis seems to depend on whether atypical ("worrisome") histological features are available or not. Surgery turned out as the most appropriate treatment, without reaching any agreement on surgery timing. Further studies on larger population are needed to better understand the biological features of pancreatic PEComa, in order to set up guidelines in the diagnosis, treatment and follow-up.

Unresectable hepatic PEComa: a rare malignancy treated with stereotactic body radiation therapy (SBRT) followed by complete resection

BACKGROUND

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors occurring in various anatomic regions. Although diagnostic criteria and treatment management are not established, current treatment options consist of surgery and chemotherapy including mTOR inhibitors. Stereotactic body radiation therapy (SBRT) is a non-invasive ablative treatment which has shown excellent control rates for more common types of unresectable liver tumors and metastases. In this report we present a rare case of PEComa of the liver that was treated by stereotactic radiotherapy followed by resection. Staging and evaluation of treatment response was done by FDG-PET/CT. This case highlights the potential of SBRT as a neoadjuvant treatment even for rare liver malignancies. It is the first case of liver PEComa treated by SBRT and resection.

CASE PRESENTATION

A 52-year-old woman presented at an external hospital with abdominal pressure and pain in the right upper abdominal quadrant. A CT scan showed a 700 cm3 liver lesion in segment IV. In repeated biopsy in July 2015 histopathological workup showed a pleomorphic epitheloid tumor with small to medium sized cells expressing vimentin and melan-A while being negative for cytokeratin establishing the diagnosis of PEComa of the liver. To achieve high, ablative doses a stereotactic body radiotherapy (SBRT) technique was chosen consisting of 60Gy (biologically effective dose 105Gy) in 8 fractions of 7.5Gy. Radiotherapy planning was based on MRI resulting in a planning target volume (PTV) of 1944 cm3. Treatment toxicity was limited to a slight elevation of transaminases (grade 1 and 3). A complete resection was performed 21 weeks after radiotherapy confirmed by negative surgical margins. At last follow-up 21 months after therapy, MRI showed neither local nor distant tumor recurrence. The patient was in stable condition (ECOG 1) and without late radiation toxicity.

CONCLUSIONS

This is the first documented case of liver PEComa treated by SBRT and resection. A favorable post-treatment course demonstrates that SBRT is a potential neoadjuvant treatment that is capable of reducing an inoperable rare liver tumor to a resectable lesion.

Factors associated with the number and size of renal angiomyolipomas in sporadic angiomyolipoma (sAML): a study of adult patients with sAML managed in a Dutch tertiary referral center

PURPOSE

To describe the patient characteristics, treatments, disease monitoring, and kidney function of patients with sporadic angiomyolipoma (sAML), stratified by the number and size of renal angiomyolipomas (AMLs).

METHODS

Single-center retrospective analysis of patients with sAML treated from 1990 to 2015 in a dedicated clinic for inheritable tumor syndromes in a tertiary referral center from the Netherlands. Patients' first AML assessment at the clinic was defined as the index date. Patient characteristics were measured at the index date. Treatments, disease monitoring, and kidney function were measured post-index date.

RESULTS

The study sample included 53 patients followed for a total of 184.6 patient-years. At the index date, the largest AML was ≥ 3.5 cm for 26 patients and < 3.5 cm for 27 patients (including six patients with five or more AMLs of < 3.5 cm). As compared to patients with AMLs < 3.5 cm, patients with largest AML ≥ 3.5 cm had higher frequency of pre-index bleeding episodes (31 vs. 4%), pre-index hypertension (35 vs. 15%), post-index nephrectomy (19 vs. 4%), post-index embolization (8 vs. 0%), and post-index renal scans (1.14 vs. 0.74 scans/year). Kidney impairment was especially pronounced in young adults with AML ≥ 3.5 cm. On average, patients with sAML developed chronic kidney disease stage two earlier than the general Dutch population (age 42 vs. 55 years), but later than the patients with tuberous sclerosis complex (35 years).

CONCLUSIONS

Patients with sAML, especially those with larger AMLs, have high disease burden.

Management of the "Other" retroperitoneal sarcomas

The focus of this review is on the management of the less common sarcomas occurring in the retroperitoneal space, including solitary fibrous tumor (SFT), malignant peripheral nerve sheath tumor (MPNST), perivascular epithelioid cell tumor (PEComa), and undifferentiated pleomorphic sarcoma (UPS) of the psoas muscle. As for other retroperitoneal sarcomas, surgical resection is the mainstay of curative therapy, and multidisciplinary preoperative assessment, including percutaneous needle biopsy for histologic confirmation, is the basis for personalized management, as the surgical management, and the integration of systemic therapy and radiation therapy is unique to each histologic subtype.

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.

Renal angiomyolipoma: a radiological classification and update on recent developments in diagnosis and management

Angiomyolipoma is the most common benign solid renal neoplasm observed in clinical practice. Once thought to be a hamartoma and almost always diagnosed by the imaged-based detection of fat, angiomyolipomas are now known to consist of a heterogeneous group of neoplasms. Although all are considered perivascular epithelioid cell tumors, many display different pathology, imaging features, and clinical behavior. The importance of understanding this group of neoplasms is emphasized by the fact that many types of angiomyolipoma contain little to no fat, and despite being benign, sometimes escape a pre-operative diagnosis. These types of angiomyolipomas can all be considered when encountering a renal mass that is both hyperattenuating relative to renal parenchyma on unenhanced CT and T2-hypointense, features that reflect their predominant smooth muscle component. We review recent developments and provide a radiological classification of angiomyolipomas that helps physicians understand the various types and learn how to both diagnose and manage them.

Renal sinus fat invasion and tumoral thrombosis of the inferior vena cava-renal vein: only confined to renal cell carcinoma

Epithelioid angiomyolipoma (E-AML), accounting for 8% of renal angiomyolipoma, is usually associated with tuberous sclerosis (TS) and demonstrates aggressive behavior. E-AML is macroscopically seen as a large infiltrative necrotic tumor with occasional extension into renal vein and/or inferior vena cava. However, without history of TS, renal sinus and venous invasion E-AML would be a challenging diagnosis, which may lead radiologists to misinterpret it as a renal cell carcinoma (RCC). In this case presentation, we aimed to report cross-sectional imaging findings of two cases diagnosed as E-AML and pathological correlation of these aforementioned masses mimicking RCC.

Renal epithelioid angiomyolipoma with malignant features: Histological evaluation and novel immunohistochemical findings

Renal epithelioid angiomyolipoma (EAML) is a potentially malignant tumor type whose characteristics and biomarkers predictive of malignant behavior have not been elucidated. Here, we report three cases of renal EAML with malignant features but without histories of tuberous sclerosis complex. Case 1 involved a 29-year-old man with a 12-cm solid mass in the right kidney who underwent radical right nephrectomy. Case 2 involved a 22-year-old woman with a retroperitoneal mass who underwent radical right nephrectomy and retroperitoneal tumorectomy. Local recurrence was detected 7 years post-surgery. Case 3 involved a 23-year-old man with a 14-cm solid mass in the left kidney who underwent radical left nephrectomy. Microscopically, the tumors in all cases demonstrated proliferation of epithelioid cells with atypia, mitotic activity, necrosis, hemorrhage, and vascular invasion. Epithelioid cells in all cases were immunohistochemically positive for melanocytic and myoid markers and weakly positive for E-cadherin and β-catenin. Immunohistochemistry revealed activation of the mammalian target of rapamycin pathway. Here, we report the morphological and immunohistochemical features of clinically or histologically malignant renal EAML.

Renal angiomyolipoma: a radiological classification and update on recent developments in diagnosis and management

Angiomyolipoma is the most common benign solid renal neoplasm observed in clinical practice. Once thought to be a hamartoma and almost always diagnosed by the imaged-based detection of fat, angiomyolipomas are now known to consist of a heterogeneous group of neoplasms. Although all are considered perivascular epithelioid cell tumors, many display different pathology, imaging features, and clinical behavior. The importance of understanding this group of neoplasms is emphasized by the fact that many types of angiomyolipoma contain little to no fat, and despite being benign, sometimes escape a pre-operative diagnosis. These types of angiomyolipomas can all be considered when encountering a renal mass that is both hyperattenuating relative to renal parenchyma on unenhanced CT and T2-hypointense, features that reflect their predominant smooth muscle component. We review recent developments and provide a radiological classification of angiomyolipomas that helps physicians understand the various types and learn how to both diagnose and manage them.

Comprehensive clinical and pathological analysis of aggressive renal epithelioid angiomyolipoma: report of three cases

Renal angiomyolipoma (AML) is recognized as a benign hamartomatous lesion arising in the kidney with no obvious malignant potential. However, epithelioid AML (EAML), a rare variant of AML, is potentially malignant, with aggressive clinical features. It can occur in patients with or without tuberous sclerosis. Because EAML may mimic renal cell carcinoma in imaging studies, differentiation of this tumor from renal cell carcinoma preoperatively is difficult. At times, the lesions may extend into the renal vein and inferior vena cava or metastasize to other organs such as the lung and liver. To clarify the biological nature of EAML, three specific cases that we encountered in clinical practice are analyzed and reported in detail.

Targeted therapies in rare sarcomas: IMT, ASPS, SFT, PEComa, and CCS

This article highlights the data currently available on the activity of targeted medical treatment in a subgroup of rare entities within soft tissue sarcomas, including inflammatory myofibroblastic tumor, alveolar soft part sarcoma, solitary fibrous tumor, malignant perivascular epithelioid cell tumor (PEComa), and clear cell sarcoma.

Genetics of rare mesenchymal tumors: implications for targeted treatment in DFSP, ASPS, CCS, GCTB and PEComa

Soft tissue and bone sarcomas comprise a heterogeneous group of mesenchymal tumors that include roughly 130 distinct diagnostic entities. Many of them are exceptionally rare, with only few cases diagnosed worldwide each year. Development of novel targeted treatment in this group of tumors is of special importance since many sarcoma subtypes are resistant to conventional chemotherapy and the effective therapeutic options are limited. In this review we aim to discuss the molecular implications for targeted therapy in selected rare soft tissue and bone sarcoma subtypes, including dermatofibrosarcoma protuberans (DFSP), alveolar soft part sarcoma (ASPS), clear cell sarcoma (CCS), giant cell tumor of bone (GCTB) and perivascular epithelioid cell neoplasms (PEComas). This article is part of a Directed Issue entitled: Rare cancers.

Fatal malignant metastastic epithelioid angiomyolipoma presenting in a young woman: case report and review of the literature

Epithelioid angiomyolipomas (EAMLs) are rare mesenchymal tumors whose malignant variant is extremely uncommon and highly aggressive. Treatment strategies include chemo radiation, transcatheter arterial embolization and surgical resection, which has remained the mainstay treatment. Targeted therapies including mammalian target of rapamycin (mTOR) inhibitors such as Temsirolimus may offer some hope for progressive malignant EAMLs that are not amenable to other treatment modalities. We report a fatal case in a young female who presented with rapidly progressive metastatic EAML that did not respond to mTOR therapy. The literature has shown reduction in tumor burden with the use of mTOR inhibitors, but unfortunately due to the rarity of malignant EAML, a meaningful approach to treatment remains challenging.

Ridaforolimus in advanced or metastatic soft tissue and bone sarcomas

Patient outcomes remain poor for advanced or metastatic soft tissue sarcomas (STS) and bone sarcomas despite a growing number of clinical trials involving single- and multi-agent chemotherapy. mTOR is an intracellular kinase that plays a central role in regulating cell growth, metabolism, survival and proliferation. mTOR inhibitors including temsirolimus, everolimus and ridaforolimus have demonstrated broad anticancer activity. Ridaforolimus is a non-prodrug analog of rapamycin (sirolimus) with conserved affinity for mTOR but improved solubility, stability and bioavailability when compared with sirolimus. Early clinical trials reveal a reproducible and predictable pharmacokinetic profile, a potent, rapid and prolonged target inhibition and an acceptable safety and tolerability profile. Phase II and III trials of ridaforolimus have produced promising clinical activity against advanced sarcomas and will be presented.

Epithelioid angiomyolipoma of the kidney: radiological imaging

OBJECTIVES

To review the imaging findings of renal epithelioid angiomyolipomas.

METHODS

Eight patients treated at two institutions were pathologically diagnosed as having epithelioid angiomyolipoma. All of them underwent computed tomography, and four underwent magnetic resonance imaging. The tumor size, existence of fat, heterogeneity, computed tomography attenuation, degree of enhancement, enhancement pattern and magnetic resonance imaging signal intensity were evaluated.

RESULTS

Intratumoral fat was not detected in any of the cases. On unenhanced computed tomography, the intratumoral attenuation was hyperattenuating in six of the seven patients who were examined using this modality. On T2-weighted images, the signal intensity of the solid component, cyst wall or septum was low in three of the four cases. Four of the eight cases were heterogeneous solid-type accompanied by hemorrhage, necrosis or hyalinization. One homogeneous solid-type lesion was large in size and was pathologically accompanied by neither hemorrhage nor necrosis. All three multilocular cystic types were pathologically accompanied by massive hemorrhage in the cystic component. One was accompanied by spontaneous perirenal hematoma.

CONCLUSIONS

The radiological appearance of most epithelioid angiomyolipomas has a tendency to be hyperattenuating on unenhanced computed tomography images, with low intensities on T2-weighted images. They can be heterogeneously solid, homogeneously solid or a multilocular cystic lesion with massive hemorrhage.

Role of mammalian target of rapamycin inhibitor in the treatment of metastatic epithelioid angiomyolipoma: a case report

Epithelioid angiomyolipoma has malignant potential; however, no effective therapy has been established for advanced cases. A 50-year-old woman with a history of right nephrectomy for epithelioid angiomyolipoma was referred to our institution. Computed tomography and magnetic resonance imaging showed multiple tumors in her lung, liver and pelvic cavity. The liver and pelvic tumor specimens obtained by needle biopsy confirmed the diagnosis of epithelioid angiomyolipoma recurrence. The patient was treated with everolimus (10 mg/day). Three months later, pulmonary lesions disappeared; liver and pelvic tumors significantly shrank in size, but the pelvic tumor gradually enlarged again. We carried out surgical resection of the residual liver and pelvic cavity tumors. Although the mammalian target of rapamycin inhibitor seems to be effective for treating epithelioid angiomyolipoma, its long-term effects remain unknown. Thus, aggressive administration of a multidisciplinary treatment including molecular target therapy and surgical resection is required to improve the prognosis of epithelioid angiomyolipoma.

Non-clear cell renal cell carcinoma: does the mammalian target of rapamycin represent a rational therapeutic target?

Non-clear cell renal cell carcinomas (nccRCCs) comprise a heterogenous and poorly characterized group of tumor types for which few treatments have been approved. Although targeted therapies have become the cornerstones of systemic treatment for metastatic renal cell carcinoma, patients with nccRCC have been excluded from many pivotal clinical trials. As such, robust clinical evidence supporting the use of these agents in patients with nccRCC is lacking. Here, we review the disparate nccRCC subtypes, the criteria for diagnosis, and the prognoses associated with each subtype, in addition to evaluating the potential use of mammalian target of rapamycin (mTOR) inhibitors in treating patients with nccRCC. Both genetic analyses and preclinical research indicate a central role for mTOR in nccRCC; a therapy that targets this ubiquitous regulator of cellular signaling could prove efficacious across various tumor subtypes. Results from recent studies exploring targeted therapies as both monotherapy and combination therapy have provided early indications of efficacy in patients with nccRCC. Exploratory analyses support further research with the mTOR inhibitors everolimus and temsirolimus in patients with nccRCC. Current clinical practice guidelines support the use of mTOR inhibitors in patients with nccRCC; however, these recommendations are based on low levels of evidence. Further results from randomized, controlled clinical trials are needed to determine the optimal choice of therapy for patients with nccRCC. Results from ongoing clinical trials of mTOR inhibitors and other agents in nccRCC, as well as their impact on the nccRCC treatment paradigm, are eagerly awaited.