Hereditary leiomyomatosis and renal cell cancer: update on clinical and molecular characteristics

Sarcomas Associated With Genetic Cancer Predisposition Syndromes: A Review

: Sarcomas are rare mesenchymal malignancies that demonstrate great clinical and biological heterogeneity. A variety of sarcomas develop in the context of well-defined heritable cancer predisposition syndromes, associations that are often overlooked, given the rarity and diversity of sarcomas and the equivalent relative infrequency of cancer genetic syndromes. This review describes in detail selected heritable cancer predisposition syndromes that are known to be associated with sarcomas. Beyond the molecular and clinical features that define each syndrome, disparities in clinical presentation, natural history, and treatment of syndrome-associated compared with otherwise histologically identical sporadic sarcomas will be described. The clinical approach to selected sarcoma subsets with a view to identifying possible associations with these syndromes will then be described. Although the treatment of the majority of sarcomas will not differ significantly between sporadic cases and those associated with predisposition syndromes, knowledge of features such as unique anatomic sites of affliction or excess toxicities with particular cytotoxic therapies can facilitate alterations in therapeutic strategies to maximize efficacy and minimize toxicity. In addition, recognition of cancer genetic predisposition syndrome will allow patients and their relatives to undertake appropriate genetic counseling and testing, as well as screening, surveillance, and interventional measures, as needed. Situating sarcomas within the genetic endowment of particular patients-specifically that which confers a higher risk of malignancy-will enable clinicians to better manage the patient as a whole, complementing the great efforts currently routinely undertaken to genomically characterize somatic tumor changes with a view to achieving the dream of personalized medicine.

IMPLICATIONS FOR PRACTICE

Sarcomas are uncommon malignancies that often occur sporadically but can also arise in the setting of a recognized heritable cancer predisposition syndrome. Identification of such associations when present can facilitate refinement and optimization of treatment strategies for the sarcoma so as to minimize toxicity and maximize efficacy. Discerning genetic predisposition can also facilitate institution of genetic counseling, as well as screening or surveillance schema for both the patient and his or her relatives, if required. Vigilance for these syndromes has the potential to significantly enhance the quality and comprehensiveness of sarcoma clinical management.

Gynecologic Manifestations of Less Commonly Encountered Hereditary Syndromes

This review covers gynecologic manifestations that may occur in rare hereditary syndromes. Recent advances in disorders, such as hereditary leiomyomatosis, renal cell carcinoma syndrome and tuberous sclerosis complex, are discussed as well as lesions that occur in von Hippel-Lindau syndrome, nevoid basal cell carcinoma syndrome, Cowden syndrome, Ollier disease/Maffucci syndrome, and Carney complex. Characteristic clinicopathologic features of each of these syndromes are discussed with an emphasis on the key features that enable pathologists to identify patients at highest risk for these diseases.

MED12 mutations and FH inactivation are mutually exclusive in uterine leiomyomas

Background:

Uterine leiomyomas from hereditary leiomyomatosis and renal cell cancer (HLRCC) patients are driven by fumarate hydratase (FH) inactivation or occasionally by mediator complex subunit 12 (MED12) mutations. The aim of this study was to analyse whether MED12 mutations and FH inactivation are mutually exclusive and to determine the contribution of MED12 mutations on HLRCC patients' myomagenesis.

Methods:

MED12 exons 1 and 2 mutation screening and 2SC immunohistochemistry indicative for FH deficiency was performed on a comprehensive series of HLRCC patients' (122 specimens) and sporadic (66 specimens) tumours. Gene expression analysis was performed using Affymetrix GeneChip Human Exon Arrays (Affymetrix, Santa Clara, CA, USA).

Results:

Nine tumours from HLRCC patients harboured a somatic MED12 mutation and were negative for 2SC immunohistochemistry. All remaining successfully analysed lesions (107/116) were deficient for FH. Of sporadic tumours, 35/64 were MED12 mutation positive and none displayed a FH defect. In global gene expression analysis FH-deficient tumours clustered together, whereas HLRCC patients' MED12 mutation-positive tumours clustered together with sporadic MED12 mutation-positive tumours.

Conclusions:

Somatic MED12 mutations and biallelic FH inactivation are mutually exclusive in both HLRCC syndrome-associated and sporadic uterine leiomyomas. The great majority of HLRCC patients' uterine leiomyomas are caused by FH inactivation, but incidental tumours driven by somatic MED12 mutations also occur. These MED12 mutation-positive tumours display similar expressional profiles with their sporadic counterparts and are clearly separate from FH-deficient tumours.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma (RCC) compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell (tubulo) papillary RCC, Xp11 translocation RCC, t(6;11) RCC, succinate dehydrogenase (SDH)-deficient RCC, acquired cystic disease-associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors (HOCT). In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

[Hereditary renal tumors: More common than expected?]

Renal cell carcinomas are associated with hereditary tumor syndromes in approximately 5 % of cases. In patients with a hereditary predisposition, tumors show an earlier age of onset, often with a multicentric and bilateral manifestation. While some patients with renal cell carcinoma can be classified into well-characterized kidney cancer syndromes others have a genetic background which is still poorly understood. Most of the specific tumor syndromes are associated with a histopathologically distinct renal cell tumor phenotype. The recognition of patients with hereditary renal cell carcinoma and the identification of individual family members with a higher risk of development of renal tumors is important for early tumor detection and treatment. This manuscript reviews the clinical pathological and molecular findings of hereditary renal cell carcinoma syndromes.

First Presentation of Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome in Pregnancy

BACKGROUND

Reed's syndrome, also known as hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome, is an autosomal dominant condition in which affected individuals may develop cutaneous leiomyomas, uterine fibroids, and renal cell carcinoma.

OBJECTIVE

This report describes a unique case of HLRCC because it presented in pregnancy with development of cutaneous pilar leiomyomas.

METHODS

Review of the literature for previous cases of Reed's syndrome during pregnancy including PubMed and Medline search.

RESULTS

Genetic testing of this patient demonstrated a mutation in the fumarate hydratase (FH) gene. Review of the literature showed only 1 previous case series that described the onset of cutaneous lesions during pregnancy.

CONCLUSION

This case serves as a reminder that there may exist a correlation between pregnancy and the first manifestation of cutaneous lesions in patients with HLRCC, and thus an increased clinical suspicion is warranted during this period.

Integrated data analysis reveals uterine leiomyoma subtypes with distinct driver pathways and biomarkers

Uterine leiomyomas are common benign smooth muscle tumors that impose a major burden on women's health. Recent sequencing studies have revealed recurrent and mutually exclusive mutations in leiomyomas, suggesting the involvement of molecularly distinct pathways. In this study, we explored transcriptional differences among leiomyomas harboring different genetic drivers, including high mobility group AT-hook 2 (HMGA2) rearrangements, mediator complex subunit 12 (MED12) mutations, biallelic inactivation of fumarate hydratase (FH), and collagen, type IV, alpha 5 and collagen, type IV, alpha 6 (COL4A5-COL4A6) deletions. We also explored the transcriptional consequences of 7q22, 22q, and 1p deletions, aiming to identify possible target genes. We investigated 94 leiomyomas and 60 corresponding myometrial tissues using exon arrays, whole genome sequencing, and SNP arrays. This integrative approach revealed subtype-specific expression changes in key driver pathways, including Wnt/β-catenin, Prolactin, and insulin-like growth factor (IGF)1 signaling. Leiomyomas with HMGA2 aberrations displayed highly significant up-regulation of the proto-oncogene pleomorphic adenoma gene 1 (PLAG1), suggesting that HMGA2 promotes tumorigenesis through PLAG1 activation. This was supported by the identification of genetic PLAG1 alterations resulting in expression signatures as seen in leiomyomas with HMGA2 aberrations. RAD51 paralog B (RAD51B), the preferential translocation partner of HMGA2, was up-regulated in MED12 mutant lesions, suggesting a role for this gene in the genesis of leiomyomas. FH-deficient leiomyomas were uniquely characterized by activation of nuclear factor erythroid 2-related factor 2 (NRF2) target genes, supporting the hypothesis that accumulation of fumarate leads to activation of the oncogenic transcription factor NRF2. This study emphasizes the need for molecular stratification in leiomyoma research and possibly in clinical practice as well. Further research is needed to determine whether the candidate biomarkers presented herein can provide guidance for managing the millions of patients affected by these lesions.

MiT Family Translocation-Associated Renal Cell Carcinoma: A Contemporary Update With Emphasis on Morphologic, Immunophenotypic, and Molecular Mimics

Translocation-associated renal cell carcinoma (t-RCC) is a relatively uncommon subtype of renal cell carcinoma characterized by recurrent gene rearrangements involving the TFE3 or TFEB loci. TFE3 and TFEB are members of the microphthalmia transcription factor (MiT) family, which regulates differentiation in melanocytes and osteoclasts, and MiT family gene fusions activate unique molecular programs that can be detected immunohistochemically. Although the overall clinical behavior of t-RCC is variable, emerging molecular data suggest the possibility of targeted approaches to advanced disease. Thus, distinguishing t-RCC from its morphologic, immunophenotypic, and molecular mimics may have important clinical implications. The differential diagnosis for t-RCC includes a variety of common renal neoplasms, particularly those demonstrating clear cell and papillary features; in addition, because of immunophenotypic overlap and/or shared molecular abnormalities (ie, TFE3 gene rearrangement), a distinctive set of nonepithelial renal tumors may also warrant consideration. Directed ancillary testing is an essential aspect to the workup of t-RCC cases and may include a panel of immunohistochemical stains, such as PAX8, pancytokeratins, epithelial membrane antigen, carbonic anhydrase IX, HMB-45, and Melan-A. Dual-color, break-apart fluorescent in situ hybridization for TFE3 or TFEB gene rearrangement may be helpful in diagnostically challenging cases or when molecular confirmation is needed.

Diagnosis and Management of Hereditary Renal Cell Cancer

Renal cell cancer (RCC) is the common denominator for a heterogeneous group of diseases. The subclassification of these tumours is based on histological type and molecular pathogenesis. Insight into molecular pathogenesis has led to the development of targeted systemic therapies. Genetic susceptibility is the principal cause of RCC in about 2-4% of cases. Hereditary RCC is the umbrella term for about a dozen different conditions, the most frequent of which is von Hippel-Lindau disease . Here, we describe the main hereditary RCC syndromes, consider criteria for referral of RCC patients for clinical genetic assessment and discuss management options for patients with hereditary RCC and their at-risk relatives.

Fumarate Hydratase Mutation in a Young Woman With Uterine Leiomyomas and a Family History of Renal Cell Cancer

BACKGROUND

Heterozygous gene mutations in fumarate hydratase can result in a syndrome characterized by hereditary (cutaneous and uterine) leiomyomatosis and renal cell cancer. This disorder has been described in more than 200 families, but the prevalence of the disease is unknown.

CASE

A 22 year-old woman of Bangladeshi lineage presented with menorrhagia and pelvic pain secondary to uterine leiomyomas and underwent an abdominal myomectomy. Because of a family history of renal cell cancer, she was tested for fumarate hydratase mutations and found to be a carrier. As a result of the risk of renal cell cancer associated with this mutation, an annual surveillance plan was initiated.

CONCLUSION

Fumarate hydratase gene mutations should be considered in women presenting with leiomyomas and a family history of renal cancer.

Pathology, therapy and prognosis of papillary renal carcinoma

Papillary renal cell carcinoma (pRCC) accounts for approximately 10% of renal parenchymal tumors. There are two pRCC subtypes reported in several studies, but at present, there is limited molecular evidence to validate this pRCC subtyping in the daily routine. The utility of subtyping pRCC is based on reports describing that pRCC subtype is an independent predictor of outcome, with type 1 tumors showing significantly better survival than type 2 tumors. In this article, we summarize the relevant knowledge on pRCC regarding tumor features: clinical presentation, histopathology, electron microscopy, immunohistochemistry, cytogenetics, genetic/molecular and prognosis. We present an overview of the currently available pRCC treatment options and some of the new promising agents.

Sustained NRF2 activation in hereditary leiomyomatosis and renal cell cancer (HLRCC) and in hereditary tyrosinemia type 1 (HT1)

The nuclear erythroid 2-like 2 transcription factor (NRF2), is a major regulator of cellular redox balance. Although NRF2 activation is generally regarded as beneficial to human health, recent studies have identified that sustained NRF2 activation is over-represented in many cancers. This raises the question regarding the role of NRF2 activation in the development and progression of those cancers. This review focuses on the mechanisms and the effects of NRF2 activation in two hereditary cancer predisposition syndromes: hereditary leiomyomatosis and renal cell cancer (HLRCC) and hereditary tyrosinemia type 1 (HT1). Because the cancer initiating mutations in these hereditary syndromes are well defined, they offer a unique opportunity to explore the roles of NRF2 activation in the early stages of carcinogenesis. Over the years, a variety of approaches have been utilized to study the biology of HLRCC and HT1. In HLRCC, in vitro studies have demonstrated the importance of NRF2 activation in sustaining cancer cell proliferation. In the mouse model of HT1 however, NRF2 activation seems to protect cells from malignant transformation. In both HT1 and HLRCC, NRF2 activation promotes the clearance of electrophilic metabolites, enabling cells to survive cancer-initiating mutations. Biological insights gained from the hereditary syndromes' studies may shed light on to the roles of NRF2 activation in sporadic tumours.

Novel splice site mutation in the fumarate hydratase (FH) gene is associated with multiple cutaneous leiomyomas in a Japanese patient

Cutaneous leiomyoma is a benign skin tumor that originates from the smooth muscle, such as the arrector pili muscle of the hair follicles. Familial cases with multiple cutaneous leiomyomas exist, which typically show an autosomal dominant inheritance trait. Most patients with the disease are known to carry heterozygous germ line mutations in the fumarate hydratase (FH) gene and can be complicated by tumors in internal organs, especially uterine leiomyoma and renal cell cancer in high frequency. In this study, we identified a Japanese male patient with multiple cutaneous leiomyomas and found a novel heterozygous splice site mutation, c.738 + 2T>A, in the FH gene of the patient, which was unexpectedly inherited from his unaffected father. Further analysis demonstrated loss of heterozygosity in the tumor tissue, which resulted in a hemizygote state of the mutant allele. Expression studies with the tumor tissue showed that the mutation led to skipping of exon 5 at mRNA levels, which was predicted to cause an in-frame deletion of FH protein (p.Ser186_Gln246del). The protein structure analysis strongly suggested that the deletion would severely disrupt the conformation of the FH protein including the substrate-binding domain, and thus would severely affect the expression and the function. Our findings further disclose the molecular basis of multiple cutaneous leiomyomas and also provide precious information to the mutation carriers in the family for an early diagnosis of renal cell cancer in the future.

Leiomyoma cutis: a focused review on presentation, management, and association with malignancy

Cutaneous leiomyomas (CLs) are rare, sporadic, or inherited tumors of smooth muscle origin associated with various disorders. Hereditary leiomyomatosis and renal cell cancer (HLRCC) is the primary tumor predisposition syndrome associated with inherited CLs, affecting 180 families worldwide, with significant mortality. CLs are subdivided into piloleiomyomas, genital leiomyomas, and angioleiomyomas based on their smooth muscle of origin, as well as their clinicopathologic features. Piloleiomyomas, derived from arrector pili muscle, are solitary or multiple firm papulonodules located typically on the extremities and trunk; genital leiomyomas, derived from dartoic, vulvar, or mammary smooth muscle, are solitary papulonodules or pedunculated papules located on the scrotum, vulva, or nipple; and angioleiomyomas, which include solid, cavernous, or venous subtypes, are derived from the tunica media of small arteries and veins and typically present on the extremities. Partial/excisional biopsy is required for diagnosing all CLs. Histology shows interlacing fascicles of spindle cells with moderate amounts of eosinophilic cytoplasm and a blunt-ended, elongated nucleus with perinuclear halos. Surgical excision is curative for CLs, with other management options including medical or destructive therapy; active surveillance is advised to monitor HLRCC-associated neoplasms, with pharmacological therapies under active research.

Hereditary leiomyomatosis and renal cell cancer (HLRCC): renal cancer risk, surveillance and treatment

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant condition in which susceptible individuals are at risk for the development of cutaneous leiomyomas, early onset multiple uterine leiomyomas and an aggressive form of type 2 papillary renal cell cancer. HLRCC is caused by germline mutations in the fumarate hydratase (FH) gene which inactivate the enzyme and alters the function of the tricarboxylic acid (Krebs) cycle. Issues surrounding surveillance and treatment for HLRCC-associated renal cell cancer were considered as part of a recent international symposium on HLRCC. The management protocol proposed in this article is based on a literature review and a consensus meeting. The lifetime renal cancer risk for FH mutation carriers is estimated to be 15 %. In view of the potential for early onset of RCC in HLRCC, periodic renal imaging and, when available, predictive testing for a FH mutation is recommended from 8 to 10 years of age. However, the small risk of renal cell cancer in the 10-20 years age range and the potential drawbacks of screening should be carefully discussed on an individual basis. Surveillance preferably consists of annual abdominal MRI. Treatment of renal tumours should be prompt and generally consist of wide-margin surgical excision and consideration of retroperitoneal lymph node dissection. The choice for systemic treatment in metastatic disease should, if possible, be part of a clinical trial. Screening procedures in HLRCC families should preferably be evaluated in large cohorts of families.

Germline FH mutations presenting with pheochromocytoma

CONTEXT

At least a third of the patients with pheochromocytoma (PCC) or paraganglioma (PGL) harbor an underlying germline mutation in a known PCC/PGL gene. Mutations in genes (SDHB, SDHD, SDHC, and SDHA) encoding a component of the tricarboxylic acid cycle, succinate dehydrogenase (SDH), are a major cause of inherited PCC and PGL. SDHB mutations are also, albeit less frequently, associated with inherited renal cell carcinoma. Inactivation of SDH and another tricarboxylic acid cycle component, fumarate hydratase (FH), have both been associated with abnormalities of cellular metabolism, responsible for the activation of hypoxic gene response pathways and epigenetic alterations (eg, DNA methylation). However, the clinical phenotype of germline mutations in SDHx genes and FH is usually distinct, with FH mutations classically associated with hereditary cutaneous and uterine leiomyomatosis and renal cell carcinoma, although recently an association with PCC/PGL has been reported.

OBJECTIVE AND DESIGN

To identify potential novel PCC/PGL predisposition genes, we initially undertook exome resequencing studies in a case of childhood PCC, and subsequently FH mutation analysis in a further 71 patients with PCC, PGL, or head and neck PGL.

RESULTS

After identifying a candidate FH missense mutation in the exome study, we then detected a further candidate missense mutation (p.Glu53Lys) by candidate gene sequencing. In vitro analyses demonstrated that both missense mutations (p.Cys434Tyr and p.Glu53Lys) were catalytically inactive.

CONCLUSIONS

These findings 1) confirm that germline FH mutations may present, albeit rarely with PCC or PGL; and 2) extend the clinical phenotype associated with FH mutations to pediatric PCC.

Genetically modeled mice with mutations in mitochondrial metabolic enzymes for the study of cancer

Mitochondrial dysfunction has long been implicated in progression of cancer. As a paradigm, the “Warburg effect,” which by means of a switch toward anaerobic metabolism enables cancer cells to proliferate in oxygen limiting conditions, is well established. Besides this metabolic transformation of tumors, it has been discovered that mutations in genes encoding mitochondrial proteins are the etiological factors in different types of cancer. This confers to mitochondrial dysfunction a causative role, rather than resultant, in tumor genesis beyond its role in tumor progression and development. Mitochondrial proteins encoded by tumor-suppressor genes are part of the succinate-dehydrogenase, the fumarate-hydratase, and the mitochondrial isocitrate-dehydrogenase enzymes, all of them participating in the Krebs cycle. The spectrum of tumors associated with mutations in these genes is becoming larger and varies between each enzyme. Several mechanisms of tumorigenesis have been proposed for the different enzymatic defects, most of them based on studies using cellular and animal models. Regarding the molecular pathways implicated in the oncogenic transformation, one of the first accepted theories was based on the constitutive expression of the hypoxia-inducible factor 1α (Hif1α) at normal oxygen tension, a theory referred to as “pseudo-hypoxic drive.” This mechanism has been linked to the three types of mutations, thus suggesting a central role in cancer. However, other alternative molecular processes, such as oxidative stress or altered chromatin remodeling, have been also proposed to play an onco-pathogenic role. In the recent years, the role of oncometabolites, a new concept emerged from biochemical studies upon these tumors, has acquired relevance as responsible for tumor formation. Nevertheless, the actual contribution of each of these mechanisms has not been definitively established. In this review, we summarize the results obtained from mouse strains genetically modified in the three different enzymes.

Uterine smooth muscle tumors with features suggesting fumarate hydratase aberration: detailed morphologic analysis and correlation with S-(2-succino)-cysteine immunohistochemistry

Rare, sporadic uterine leiomyomas arise in the setting of severe metabolic aberration due to a somatic fumarate hydratase mutation. Germline mutations account for the hereditary leiomyomatosis and renal cell carcinoma syndrome, which predisposes for cutaneous and uterine leiomyomas and aggressive renal cell carcinomas. Altered fumarate hydratase leads to fumarate accumulation in affected cells with formation of S-(2-succino)-cysteine, which can be detected with the polyclonal antibody. High levels of these modified cysteine residues are found characteristically in fumarate hydratase-deficient cells but not in normal tissues or tumors unassociated with hereditary leiomyomatosis and renal cell carcinoma syndrome. We hypothesized that S-(2-succino)-cysteine-positive leiomyomas, indicating fumarate hydratase aberration, have morphologic features that differ from those without S-(2-succino)-cysteine positivity. Hematoxylin and eosin-stained slides of uterine smooth-muscle tumors were prospectively analyzed for features suggesting hereditary leiomyomatosis and renal cell carcinoma syndrome, such as prominent eosinophilic macronucleoli with perinucleolar halos, yielding nine cases. Germline genetic testing for fumarate hydratase mutations was performed in three cases. A detailed morphological analysis was undertaken, and S-(2-succino)-cysteine immunohistochemical analysis was performed with controls from a tissue microarray (leiomyomas (19), leiomyosarcomas (29), and endometrial stromal tumors (15)). Of the nine study cases, four had multiple uterine smooth muscle tumors. All cases had increased cellularity, staghorn vasculature, and fibrillary cytoplasm with pink globules. All cases had inclusion-like nucleoli with perinuclear halos (7 diffuse, 1 focal). All showed diffuse granular cytoplasmic labeling with the S-(2-succino)-cysteine antibody. Two of three tested patients had germline fumarate hydratase mutations. Only one leiomyoma from the tissue microarray controls was immunohistochemically positive, and it showed features similar to other immunohistochemically positive cases. Smooth-muscle tumors with fumarate hydratase aberration demonstrate morphological reproducibility across cases and S-(2-succino)-cysteine immuno-positivity. Although the features described are not specific for the germline fumarate hydratase mutation or the hereditary leiomyomatosis and renal cell carcinoma syndrome, their presence should suggest fumarate hydratase aberration. Identifying these cases is an important step in the diagnostic workup of patients with possible hereditary leiomyomatosis and renal cell carcinoma.

Hereditary leiomyomatosis and renal cell carcinoma syndrome-associated renal cancer: recognition of the syndrome by pathologic features and the utility of detecting aberrant succination by immunohistochemistry

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is an autosomal dominant disorder in which germline mutations of fumarate hydratase (FH) gene confer an increased risk of cutaneous and uterine leiomyomas and renal cancer. HLRCC-associated renal cancer is highly aggressive and frequently presents as a solitary mass. We reviewed the clinicopathologic features of 9 patients with renal tumors presenting as sporadic cases but who were later proven to have FH germline mutations. Histologically, all tumors showed mixed architectural patterns, with papillary as the dominant pattern in only 3 cases. Besides papillary, tubular, tubulopapillary, solid, and cystic elements, 6 of 9 tumors contained collecting duct carcinoma-like areas with infiltrating tubules, nests, or individual cells surrounded by desmoplastic stroma. Prominent tubulocystic carcinoma-like component and sarcomatoid differentiation were identified. Although all tumors exhibited the proposed hallmark of HLRCC (large eosinophilic nucleolus surrounded by a clear halo), this feature was often not uniformly present throughout the tumor. Prior studies have shown that a high level of fumarate accumulated in HLRCC tumor cells causes aberrant succination of cellular proteins by forming a stable chemical modification, S-(2-succino)-cysteine (2SC), which can be detected by immunohistochemistry. We thus explored the utility of detecting 2SC by immunohistochemistry in the differential diagnosis of HLRCC tumors and other high-grade renal tumors and investigated the correlation between 2SC staining and FH molecular alterations. All confirmed HLRCC tumors demonstrated diffuse and strong nuclear and cytoplasmic 2SC staining, whereas all clear cell (184/184, 100%), most high-grade unclassified (93/97, 96%), and the large majority of "type 2" papillary (35/45, 78%) renal cell carcinoma cases showed no 2SC immunoreactivity. A subset of papillary (22%) and rare unclassified (4%) tumors showed patchy or diffuse cytoplasmic staining without nuclear labeling, unlike the pattern seen with confirmed HLRCC tumors. Sequencing revealed no germline or somatic FH alterations in 14 tumors that either exhibited only cytoplasmic 2SC staining (n=5) or were negative for 2SC (n=9), despite their HLRCC-like morphologic features. Our results emphasize the pivotal role of pathologic examination in the diagnosis of HLRCC patients and indicate immunohistochemical detection of 2SC as a useful ancillary tool in the differentiation of HLRCC renal tumors from other high-grade renal cell carcinomas.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC): a rapid autopsy report of metastatic renal cell carcinoma

Rapid ("warm") autopsies of patients with advanced metastatic cancer provide invaluable insight into the natural history, pathobiology, and morphology of advanced and treatment-resistant tumors. Here, we report a rapid autopsy case of a hereditary leiomyomatosis and renal cell carcinoma (HLRCC) patient with advanced metastatic renal cell carcinoma (RCC)-the first such case described for either a primary renal tumor or HLRCC-related cancer. Mutations in the fumarate hydratase (FH) gene underlie HLRCC, a rare syndrome involving cutaneous and uterine leiomyomata and aggressive kidney tumors. Loss of heterozygosity at the wild-type FH gene locus results in profound cellular metabolic derangement, "pseudohypoxic" upregulation of hypoxia-inducible factor 1α (HIF-1α)-dependent transcription, and aberrant protein succination; these molecular changes drive oncogenesis of kidney tumors in HLRCC patients. The current index patient had a high-grade RCC with classic morphologic features of HLRCC, including large nuclei with prominent eosinophilic nucleoli and perinucleolar clearing. In addition, this patient's RCC demonstrated extensive sarcomatoid and rhabdoid features-morphologies not previously well described in HLRCC-associated kidney tumors. Here, we report the extent of metastatic dissemination and supplement this unique tumor morphology with mitochondrial enzyme histochemistry and extended immunohistochemical analysis. Tumor cells strongly expressed PAX8, vimentin, CD10, and the HIF target GLUT1 and showed increased nuclear p53 accumulation; the expression of other RCC markers was negative. We also detail microscopic tubular epithelial changes in the grossly uninvolved ipsilateral renal parenchyma and demonstrate sporadic, aberrant upregulation of the HIF targets GLUT1 and CAIX in dysplastic peritumoral tubules.

Cutaneous leiomyomatosis in a mother and daughter

A 34-year-old woman with no known medical history was evaluated for multiple painful brown nodules and papules on the anterior aspect of the trunk. She mentioned a history of similar cutaneous findings on her mother. Biopsies of three lesions revealed piloleiomyomata. Renal and adrenal ultrasound revealed an isolated simple cortical cyst, and pelvic and endovaginal ultrasound revealed two uterine myomata. The clinical diagnosis of hereditary leiomyomatosis and renal cell cancer was corroborated by the identification of a heterozygous variant on exon 5 of the fumarate hydratase gene (c.578C>T p.T193I). Identification of the tumor piloleiomyoma should alert the dermatologist to this rare genodermatosis, which is associated with an increased risk of renal cell tumors, demanding multidisciplinary follow-up, and personal and family counseling.

Novel missense mutation in the FH gene in familial renal cell cancer patients lacking cutaneous leiomyomas

Background

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a rare tumor predisposition syndrome characterized by cutaneous and uterine leiomyomas and papillary type 2 renal cell cancer. Germline mutation of the fumarate hydratase (FH) gene is known to be associated with HLRCC.

Case presentation

We describe a 64-year-old father and his 39-year-old son with HLRCC who developed papillary type 2 RCCs lacking cutaneous leiomyomas at any site. A common missense mutation in the FH gene, (c.1021G > A, p.D341N) in exon 7, was detected in the 2 cases. Functional prediction with the bioinformatics programs, SIFT and Polyphen-2, reported “damaging (SIFT score 0.00)” and “probably damaging (PSIC score 1.621)” values, respectively. In 162 healthy individuals, there were no cases of a G transition to any base. Finally, (c.1021G > A) in exon 7, was identified as a point mutation.

Conclusion

We report a family with HLRCC in which a novel missense mutation was detected. A familial papillary type 2 renal cancer should be considered HLRCC unless typical cutaneous leiomyomas do not occur.

Mitochondrial dysfunctions in cancer: genetic defects and oncogenic signaling impinging on TCA cycle activity

The tricarboxylic acid (TCA) cycle is a central route for oxidative metabolism. Besides being responsible for the production of NADH and FADH2, which fuel the mitochondrial electron transport chain to generate ATP, the TCA cycle is also a robust source of metabolic intermediates required for anabolic reactions. This is particularly important for highly proliferating cells, like tumour cells, which require a continuous supply of precursors for the synthesis of lipids, proteins and nucleic acids. A number of mutations among the TCA cycle enzymes have been discovered and their association with some tumour types has been established. In this review we summarise the current knowledge regarding alterations of the TCA cycle in tumours, with particular attention to the three germline mutations of the enzymes succinate dehydrogenase, fumarate hydratase and isocitrate dehydrogenase, which are involved in the pathogenesis of tumours, and to the aberrant regulation of TCA cycle components that are under the control of oncogenes and tumour suppressors.

Non-pheochromocytoma (PCC)/paraganglioma (PGL) tumors in patients with succinate dehydrogenase-related PCC-PGL syndromes: a clinicopathological and molecular analysis

OBJECTIVE

Although the succinate dehydrogenase (SDH)-related tumor spectrum has been recently expanded, there are only rare reports of non-pheochromocytoma/paraganglioma tumors in SDHx-mutated patients. Therefore, questions still remain unresolved concerning the aforementioned tumors with regard to their pathogenesis, clinicopathological phenotype, and even causal relatedness to SDHx mutations. Absence of SDHB expression in tumors derived from tissues susceptible to SDH deficiency is not fully elucidated.

DESIGN AND METHODS

Three unrelated SDHD patients, two with pituitary adenoma (PA) and one with papillary thyroid carcinoma (PTC), and three SDHB patients affected by renal cell carcinomas (RCCs) were identified from four European centers. SDHA/SDHB immunohistochemistry (IHC), SDHx mutation analysis, and loss of heterozygosity analysis of the involved SDHx gene were performed on all tumors. A cohort of 348 tumors of unknown SDHx mutational status, including renal tumors, PTCs, PAs, neuroblastic tumors, seminomas, and adenomatoid tumors, was investigated by SDHB IHC.

RESULTS

Of the six index patients, all RCCs and one PA displayed SDHB immunonegativity in contrast to the other PA and PTC. All immunonegative tumors demonstrated loss of the WT allele, indicating bi-allelic inactivation of the germline mutated gene. Of 348 tumors, one clear cell RCC exhibited partial loss of SDHB expression.

CONCLUSIONS

These findings strengthen the etiological association of SDHx genes with pituitary neoplasia and provide evidence against a link between PTC and SDHx mutations. Somatic deletions seem to constitute the second hit in SDHB-related renal neoplasia, while SDHx alterations do not appear to be primary drivers in sporadic tumorigenesis from tissues affected by SDH deficiency.

Exomic landscape of MED12 mutation-negative and -positive uterine leiomyomas

Uterine leiomyomas are extremely common tumors originating from the smooth muscle cells of myometrium. We recently reported recurrent somatic mutations in mediator complex subunit 12 (MED12) in the majority of these lesions, and analyzed chromosomal abnormalities in leiomyomas by whole-genome sequencing. The aim of our study was to examine in detail uterine leiomyoma exomes, to search for driver mutations in MED12 mutation-negative leiomyomas and to scrutinize MED12 mutation-positive leimyomas for additional contributing mutations. We analyzed whole exome sequencing data of 27 uterine leiomyomas (12 MED12 mutation-negative and 15 MED12 mutation-positive) and their paired normal myometrium. We searched for genes, which would be recurrently mutated. No such genes were identified in MED12 mutation-negative uterine leiomyomas. Similarly, MED12 mutation-positive leiomyomas displayed no additional recurrent changes. The complete lack of novel driver point mutations in the examined series highlights the unique role of MED12 mutations in genesis of uterine leiomyomas, and suggests that these mutations alone may be sufficient for tumor development. Additional factors that cannot be detected by exome sequencing, such as somatic structural rearrangements, epigenetic events and intronic variants, are likely to have a particular impact to the development of MED12 wild-type lesions.

Characterization of uterine leiomyomas by whole-genome sequencing

BACKGROUND

Uterine leiomyomas are benign but affect the health of millions of women. A better understanding of the molecular mechanisms involved may provide clues to the prevention and treatment of these lesions.

METHODS

We performed whole-genome sequencing and gene-expression profiling of 38 uterine leiomyomas and the corresponding myometrium from 30 women.

RESULTS

Identical variants observed in some separate tumor nodules suggested that these nodules have a common origin. Complex chromosomal rearrangements resembling chromothripsis were a common feature of leiomyomas. These rearrangements are best explained by a single event of multiple chromosomal breaks and random reassembly. The rearrangements created tissue-specific changes consistent with a role in the initiation of leiomyoma, such as translocations of the HMGA2 and RAD51B loci and aberrations at the COL4A5-COL4A6 locus, and occurred in the presence of normal TP53 alleles. In some cases, separate events had occurred more than once in single tumor-cell lineages.

CONCLUSIONS

Chromosome shattering and reassembly resembling chromothripsis (a single genomic event that results in focal losses and rearrangements in multiple genomic regions) is a major cause of chromosomal abnormalities in uterine leiomyomas; we propose that tumorigenesis occurs when tissue-specific tumor-promoting changes are formed through these events. Chromothripsis has previously been associated with aggressive cancer; its common occurrence in leiomyomas suggests that it also has a role in the genesis and progression of benign tumors. We observed that multiple separate tumors could be seeded from a single lineage of uterine leiomyoma cells. (Funded by the Academy of Finland Center of Excellence program and others.).

Extreme hypothyroidism associated with sunitinib treatment for metastatic renal cancer

Although thyroid abnormalities are reported with the use of tyrosine kinase inhibitors, patients rarely require replacement therapy. The initial multicentre studies of sunitinib for metastatic renal cancer did not report hypothyroidism in fatigued patients, and thyroid tests were not routinely monitored. More recent studies, however, suggest that up to 70% of patients develop thyroid test abnormalities during treatment with sunitinib. Despite these concerns, the clinical relevance of sunitinib-induced hypothyroidism is uncertain since thyroid gland recovery is the norm in most patients. We report a case of a patient with metastatic papillary renal cell cancer on combination anti-angiogenic therapy with sunitinib, who developed unusually high thyroid stimulating hormone levels and severe symptoms despite receiving L-thyroxine. Our case also illustrates the complexity of managing sunitinib-associated thyroid dysfunction, which may be accompanied by transient thyroiditis, hyperthyroidism, and profound hypothyroidism.

MED12 exon 2 mutations in histopathological uterine leiomyoma variants

Uterine leiomyomas, or fibroids, are the most common human tumors. Based on histopathology, they can be divided into common leiomyomas and various relatively rare subtypes that mimic malignancy in one or more aspects. Recently, we showed that exon 2 of mediator complex subunit 12 (MED12) is mutated in up to 70% of common fibroids. To investigate the frequency of MED12 exon 2 mutations in histopathological uterine leiomyoma variants, we screened altogether 206 lesions, including 69 histopathologically common leiomyomas, 59 cellular (23 cellular and 36 highly cellular), 18 atypical and 26 mitotically active leiomyomas, as well as 34 uterine fibroid samples from 14 hereditary leiomyomatosis and renal cell cancer patients with a heterozygous germ line mutation in fumarate hydratase (FH). The uterine leiomyoma variants harbored MED12 exon 2 mutations significantly less frequently than common leiomyomas (P=2.93 × 10(-8)). In all, 6 mutations were detected among cellular fibroids (6/67; 8.96%), 3 among atypical fibroids (3/18; 16.67%) and 10 among mitotically active fibroids (10/26; 38.46%). Only mitotically active fibroids displayed a mutation frequency that was not statistically different from common leiomyomas (P=0.11). Three MED12 exon 2 mutations were detected among 34 tumors with a heterozygous germ line FH mutation (P=5.28 × 10(-7)). None of these tumors displayed biallelic inactivation of FH. Our results suggest that MED12 mutation positivity is a key characteristic of common leiomyomas. Cellular and atypical fibroids, in particular, may arise through different molecular mechanisms. The results also propose that MED12 and biallelic FH mutations may be mutually exclusive.

Genetic testing by cancer site: uterus

This review article discusses hereditary cancer predisposition syndromes with uterine manifestations. Lynch syndrome accounts for 2% to 3% of endometrial cancers. The identification of endometrial cancer patients at risk for Lynch syndrome is discussed, as are the characteristics of Lynch syndrome-associated endometrial cancer and the screening and prevention options for women at risk for Lynch syndrome-associated endometrial cancer. Endometrial cancer associated with PTEN hamartoma tumor syndrome (also known as Cowden syndrome) is also discussed. HLRCC (hereditary leiomyomatosis and renal cell carcinoma), which has an associated high risk of symptomatic uterine leiomyomas, is reviewed.

Hereditary papillary renal cell carcinoma primarily diagnosed in a cervical lymph node: a case report of a 30-year-old woman with multiple metastases

Background

Papillary renal cell carcinoma is a rare cancer. Some cases can be attributed to individuals with hereditary renal cell carcinomas usually consisting of the clear cell subtype. In addition, two syndromes with hereditary papillary renal cell carcinoma have been described. One is the hereditary leiomyomatosis and renal cell carcinoma, which is characterized by cutaneous and uterine leiomyomas and renal cell carcinoma mostly consisting of the papillary renal cell carcinoma type II with a worse prognosis.

Case presentation

We describe a case of a 30-year-old woman with hereditary leiomyomatosis and renal cell carcinoma syndrome with extensively metastasized papillary renal cell carcinoma, primarily diagnosed in a cervical lymph node lacking leiomyomas at any site.

Conclusion

Papillary renal cell carcinoma in young patients should be further investigated for a hereditary variant like the hereditary leiomyomatosis and renal cell carcinoma even if leiomyomas could not be detected. A detailed histological examination and search for mutations is essential for the survival of patients and relatives.

Hereditary leiomyomatosis and renal cell cancer presenting as metastatic kidney cancer at 18 years of age: implications for surveillance

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant syndrome characterized by skin piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer caused by germline mutations in the fumarate hydratase (FH) gene. Previously, we proposed renal imaging for FH mutation carriers starting at the age of 20 years. However, recently an 18-year-old woman from a Dutch family with HLRCC presented with metastatic renal cancer. We describe the patient and family data, evaluate current evidence on renal cancer risk and surveillance in HLRCC and consider the advantages and disadvantages of starting surveillance for renal cancer in childhood. We also discuss the targeted therapies administered to our patient.

Familial renal cancer as an indicator of hereditary leiomyomatosis and renal cell cancer syndrome

Hereditary Leiomyomatosis and Renal Cell Carcinoma (HLRCC) is a hereditary condition which typically presents with cutaneous and uterine leiomyomata. Papillary type II renal cell carcinoma and other less common histologic subtypes of renal cancer have been reported in HLRCC. We describe the case of a 31-year-old man in which the pathology review of his renal carcinoma and a positive family history of renal carcinoma allowed for the identification of a pathogenic mutation in the FH gene (c.698G>A;p.R233H) confirming the diagnosis of HLRCC. Recognition of this syndrome allowed for appropriate surveillance as well as identification of at-risk family members. Pathology review is essential for accurate diagnosis of a hereditary cancer syndrome in the setting of familial renal cancer.

Fumarate hydratase inactivation in renal tumors: HIF1α, NRF2, and "cryptic targets" of transcription factors

Biallelic inactivation of fumarate hydratase (FH) causes type 2 papillary renal cell carcinoma (PRCC2), uterine fibroids, and cutaneous leimyomas, a condition known as hereditary leiomyomatosis and renal cell cancer (HLRCC). The most direct effect of FH inactivation is intracellular fumarate accumulation. A majority of studies on FH inactivation over the past decade have focused on the theory that intracellular fumarate stabilizes hypoxia-inducible factor 1α (HIF1A) through competitive inhibition of HIF prolyl hydroxylases. Recently, a competing theory that intracellular fumarate activates nuclear factor (erythroid-derived 2)-like 2 (NRF2) through post-translational modification of its negative regulator. Kelch-like ECH-associated protein 1 (KEAP1) has emerged from a computational modeling study and mouse model studies. This review dissects the origin of these two governing theories and highlights the presence of chromatin-structure-regulated targets of transcription factors, which we refer to as “cryptic targets” of transcription factors. One such cryptic target is heme oxygenase I (HMOX1), the expression of which is known to be modulated by the gene product of SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4, also known as BRG1).

State of the science: an update on renal cell carcinoma

Renal cell carcinomas (RCC) are emerging as a complex set of diseases that are having a major socioeconomic impact and showing a continued rise in incidence throughout the world. As the field of urologic oncology faces these trends, several major genomic and mechanistic discoveries are altering our core understanding of this multitude of cancers, including several new rare subtypes of renal cancers. In this review, these new findings are examined and placed in the context of the well-established association of clear cell RCC (ccRCC) with mutations in the von Hippel-Lindau (VHL) gene and resultant aberrant hypoxia inducible factor (HIF) signaling. The impact of novel ccRCC-associated genetic lesions on chromatin remodeling and epigenetic regulation is explored. The effects of VHL mutation on primary ciliary function, extracellular matrix homeostasis, and tumor metabolism are discussed. Studies of VHL proteostasis, with the goal of harnessing the proteostatic machinery to refunctionalize mutant VHL, are reviewed. Translational efforts using molecular tools to elucidate discriminating features of ccRCC tumors and develop improved prognostic and predictive algorithms are presented, and new therapeutics arising from the earliest molecular discoveries in ccRCC are summarized. By creating an integrated review of the key genomic and molecular biological disease characteristics of ccRCC and placing these data in the context of the evolving therapeutic landscape, we intend to facilitate interaction among basic, translational, and clinical researchers involved in the treatment of this devastating disease, and accelerate progress toward its ultimate eradication.

[Disseminated cutaneous leiomyomas]

Cutaneous leiomyomas are benign smooth muscle tumors. Depending on the site of origin, one distinguishes three different types--piloleiomyoma, angioleiomyoma and genital leiomyoma. They appear between the first and third decades of life. A 56-year-old woman presented with painful red - brown papules and nodules on her trunk. Based on clinical and histological criteria the diagnosis of disseminated cutaneous leiomyomas was made. Because of the widespread cutaneous involvement, surgical treatment was not possible. Therefore we decided to employ a pharmacologic anti-depressive treatment. With this approach, the patient experienced considerable pain reduction.

Strong family history of uterine leiomyomatosis warrants fumarate hydratase mutation screening

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a tumor predisposition syndrome characterized by cutaneous and uterine leiomyomas and renal cell cancer. HLRCC is caused by heterozygous germline mutations in the fumarate hydratase (FH) gene. A Finnish family with nine closely related women with uterine leiomyomas was detected by an alert gynecologist. No cutaneous or renal cell tumors were reported in the family when it was referred to genetic analyses. Samples were available from seven patients, and a novel germline FH mutation was detected in five of them. Mutation carriers were symptomatic, had multiple tumors and were diagnosed at an early age. This study emphasizes the importance of considering FH mutation screening when gynecologists encounter families with multiple severe uterine leiomyoma cases. Due to possibility of phenocopies more than one patient should be tested. Early mutation detection allows regular screening of the mutation carriers and enables early detection of possible highly aggressive renal tumors. It may also affect family planning as multiple myomas at early age may significantly reduce fertility.

Revisiting the TCA cycle: signaling to tumor formation

A role for mitochondria in tumor formation is suggested by mutations in enzymes of the TCA cycle: isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH) and fumarate hydratase (FH). Although they are all components of the TCA cycle, the resulting clinical presentations do not overlap. Activation of the hypoxia pathway can explain SDH phenotypes, but recent data suggest that FH and IDH mutations lead to tumor formation by repressing cellular differentiation. In this review, we discuss recent findings in the context of both mitochondrial and cytoplasmic components of the TCA cycle, and we propose that extrametabolic roles of TCA cycle metabolites result in reduced cellular differentiation. Furthermore, activation of the pseudohypoxia pathway likely promotes the growth of these neoplasias into tumors.