The impact of vestibular schwannoma and its management on employment.

BACKGROUND: Employment is an important factor in quality of life. For vestibular schwannoma (VS) patients, employment is not self-evident, because of the sequelae of the disease or its treatment and their effects on daily life. OBJECTIVES: This study assessed employment status, sick leave (absenteeism) and being less productive at work (presenteeism) in the long-term follow-up of VS patients, and evaluated the impact of treatment strategy (active surveillance, surgery or radiotherapy). METHODS: A cross-sectional survey study was performed in a tertiary university hospital in the Netherlands. Patients completed the iMTA-post productivity questionnaire (iPCQ). Employment status was compared to that of the general Dutch population. Employment, absenteeism and presenteeism were compared between patients under active surveillance, patients after radiotherapy and post-surgical patients. RESULT: In total 239 patients participated, of which 67% were employed at the time of the study. Only 14% had a disability pension, which was comparable to the age-matched general Dutch population. The proportion of patients with absenteeism was 8%, resulting in a 4% reduction of working hours. Presenteeism was reported by 14% of patients, resulting in a 2% reduction of working hours. The median number of working hours per week was 36, and since the diagnosis, these hours had been reduced by 6%. There were no significant differences between treatment modalities. CONCLUSION: On average, long-term employment status and working hours of VS patients are comparable to the age-matched general population. Treatment strategies do not seem to differentially impact on long-term employment of VS patients.

Patient-reported factors that influence the vestibular schwannoma treatment decision: a qualitative study.

PURPOSE: In cases of small- to medium-sized vestibular schwannomas, three management strategies can be opted for: active surveillance, surgery or radiotherapy. In these cases, the patient's preference is pivotal in decision-making. The aim of this study was to identify factors that influence a patient's decision for a particular management strategy. METHODS: A qualitative inductive thematic analysis was performed based on semi-structured interviews. Eighteen patients with small- to medium-sized vestibular schwannomas were interviewed. All patients were diagnosed or treated at one of the two participating university medical centers in the Netherlands. RESULTS: Ten themes were identified that influenced the decision, classified as either medical or patient-related. The medical themes that emerged were: tumor characteristics, the physician's recommendation, treatment outcomes and the perceived center's experience. The patient-related themes were: personal characteristics, anxiety, experiences, cognitions, logistics and trust in the physician. CONCLUSION: Knowledge of the factors that influence decision-making helps physicians to tailor their consultations to arrive at a true shared decision on vestibular schwannoma management.

M-CSF and IL-34 expression as indicators for growth in sporadic vestibular schwannoma.

Macrophage colony stimulating factor and IL-34 are associated with clinical vestibular schwannoma progression. Investigating the biology behind vestibular schwannoma progression helps understanding tumor growth. Inflammation is important in the microenvironment of neoplasms. Macrophages are major players in the intratumoral infiltrate. These tumor-associated macrophages are known to stimulate angiogenesis and cell growth. M-CSF and IL-34 are cytokines that can regulate tumor-infiltrating macrophages. They are expressed by tumors and form potential targets for therapy. The goal of this study was to investigate these cytokines in vestibular schwannomas and to see if their expression is related to angiogenesis, macrophage numbers, cystic degeneration, and volumetric tumor progression. Immunohistochemical expression of M-CSF and IL-34 was analyzed in ten fast-growing vestibular schwannomas and in ten slow-growing vestibular schwannomas. Expression M-CSF and IL-34 were compared between fast- versus slow-growing and cystic versus non-cystic tumors. Data on macrophage numbers and microvessel density, known from earlier research, was also included. All tumors expressed M-CSF and its expression was higher in fast-growing tumors (p = 0.003) and in cystic tumors (p = 0.035). CD163 expression was higher in tumors with strong M-CSF expression (p = 0.003). All tumors expressed IL-34 as well, but no significant differences were found in relation to clinicopathological characteristics. This study demonstrated the expression of M-CSF and IL-34 in vestibular schwannomas. The results suggest that M-CSF is related to macrophage activity and tumor progression, making it a potential target for therapy. If a similar assumption can be made for IL-34 remains unclear.

Perfusion magnetic resonance imaging provides additional information as compared to anatomical imaging for decision-making in vestibular schwannoma.

OBJECTIVE: The added value of perfusion MRI for decision-making in vestibular schwannoma (VS) patients is unknown. MRI offers two perfusion methods: the first employing contrast agent (dynamic susceptibility contrast (DSC)-MRI) that provides information on cerebral blood volume (CBV) and cerebral blood flow (CBF), the second by magnetic labeling of blood (arterial spin labeling (ASL)-MRI), providing CBF-images. The goal of the current study is to investigate whether DSC and ASL perfusion MRI provides complimentary information to current anatomical imaging in treatment selection process of VS. METHODS: Nine patients with growing VS with extrameatal diameter >9 mm were included (>2 mm/year and 20% volume expansion/year) and one patient with 23 mm extrameatal VS without growth. DSC and ASL perfusion MRI were obtained on 3 T MRI. Perfusion in VS was scored as hyperintense, hypointense or isointense compared to the contralateral region. RESULTS: Seven patients showed hyperintense signal on DSC and ASL sequences. Three patients showed iso- or hypointense signal on at least one perfusion map (1 patient hypointense on both DSC-MRI and ASL; 1 patient isointense on DSC-CBF; 1 patient isointense on ASL). All patients showed enhancement on post-contrast T1 anatomical scan. CONCLUSION: Perfusion MR provides additional information compared to anatomical imaging for decision-making in VS.

Measurement of head and neck paragangliomas: is volumetric analysis worth the effort? A method comparison study.

OBJECTIVES: The aim of this study was to assess the reproducibility of different measurement methods and define the most workable technique for measuring head and neck paragangliomas, to determine the best method for evaluating tumour growth. The evaluation of tumour growth is vital for a 'wait-and-scan' policy, a management strategy that became increasingly important. STUDY DESIGN: Method comparison study. SETTING AND PARTICIPANTS: Thirty tumours, including carotid body, vagal body, jugulotympanic tumours and conglomerates of multiple tumours, were measured in duplicate, using linear dimensions, manual area tracing and an automated segmentation method. MAIN OUTCOME MEASURES: Reproducibility was assessed using the Bland-Altman method. RESULTS: The smallest detectable difference using the linear dimension method was 11% for carotid body and 27% for vagal body tumours, compared with 17% and 20% for the manual area tracing method. Due to the irregular shape of paragangliomas in the temporal bone and conglomerates, the manual area tracing method showed better results in these tumours (26% and 8% versus 54% and 47%). The linear dimension method was significantly faster (median 4.27 versus 18.46 minutes, P < 0.001). The automatic segmentation method yielded smallest detectable differences between 39% and 75%, and although fast (2.19 ± 1.49 minutes), it failed technically. CONCLUSIONS: Due to a relatively good reproducibility, fast and easy application, we found the linear dimension method to be the most pragmatic approach for evaluation of growth of carotid and vagal body paragangliomas. For jugulotympanic tumours, the preferred method is manual area tracing. However, volumetric changes of these tumours may be of less clinical importance than changes in relation to surrounding anatomical structures.

High prevalence of founder mutations of the succinate dehydrogenase genes in the Netherlands.

Mutations in four genes encoding subunits or cofactors of succinate dehydrogenase (SDH) cause hereditary paraganglioma and pheochromocytoma syndromes. Mutations in SDHB and SDHD are generally the most common, whereas mutations in SDHC and SDHAF2 are far less frequently observed. A total of 1045 DNA samples from Dutch paraganglioma and pheochromocytoma patients and their relatives were analyzed for mutations of SDHB, SDHC, SDHD or SDHAF2. Mutations in these genes were identified in 690 cases, 239 of which were index cases. The vast majority of mutation carriers had a mutation in SDHD (87.1%). The second most commonly affected gene was SDHAF2 (6.7%). Mutations in SDHB were found in only 5.9% of samples, whereas SDHC mutations were found in 0.3% of samples. Remarkably, 69.1% of all carriers of a mutation in an SDH gene in the Netherlands can be attributed to a single founder mutation in SDHD, c.274G>T and p.Asp92Tyr. Moreover, 88.8% of all SDH mutation carriers carry one of just six Dutch founder mutations in SDHB, SDHD and SDHAF2. The dominance of SDHD mutations is unique to the Netherlands, contrasting with the higher prevalence of SDHB mutations found elsewhere. In addition, we found that most SDH mutation-related paragangliomas-pheochromocytomas in the Netherlands can be explained by only six founder mutations in SDHAF2, SDHB and SDHD. The findings underline the regional differences in the SDH mutation spectrum, differences that should be taken into account in the development of effective screening protocols. The results show the crucial role that demographic factors play in the frequency of gene mutations.

Mutations in SDHD are the major determinants of the clinical characteristics of Dutch head and neck paraganglioma patients.

OBJECTIVE: Head and neck paragangliomas (HNPGL) are associated with mutations in genes encoding subunits of succinate dehydrogenase (SDH). The aim of this study was to evaluate SDH mutations, family history and phenotypes of patients with HNPGL in the Netherlands. DESIGN: We evaluated the clinical data and the mutation status of 236 patients referred between 1950 and 2009 to Leiden University Medical Center. RESULTS: The large majority of the patients carried mutations in SDHD (83%), and the p.Asp92Tyr Dutch founder mutation in SDHD alone accounted for 72% of all patients with HNPGL. A mutation in SDHAF2 was found in 4%, mutations in SDHB in 3% and a mutation in SDHC was identified in a single patient (0·4%). Over 80% of patients presented with positive family history, of whom 99·5% carried a mutation in an SDH gene. SDH mutations were also found in 56% of isolated patients, chiefly in SDHD (46%), but also in SDHB (8%) and SDHC (2%). The clinical parameters of these different subgroups are discussed: including the age at diagnosis, associated pheochromocytomas, tumour multifocality and malignancy rate. CONCLUSION: The majority of Dutch patients with HNPGL present with a positive family history, in contrast to other European countries. The clinical characteristics of patients with HNPGL are chiefly determined by founder mutations in SDHD, the major causative gene in both familial and isolated patients with HNPGL. The high frequency of founder mutations in SDHD suggests a higher absolute prevalence of paraganglioma syndrome in the Netherlands.

Pheochromocytomas and extra-adrenal paragangliomas detected by screening in patients with SDHD-associated head-and-neck paragangliomas.

Patients with SDHD-associated head-and-neck paragangliomas (HNP) are at risk for developing pheochromocytomas for which screening has been advised. To assess clinical, biochemical, and radiological outcomes of screening in a large single-center cohort of SDHD-positive patients with HNP and to address the necessity for repetitive follow-up, we evaluated 93 patients with SDHD-associated HNP (p.Asp92Tyr, p.Leu139Pro). Screening consisted of measurement of 24 h urinary excretion of catecholamines and/or their metabolites in duplicate, which was repeated with intervals of 2 years if initial biochemical screening was negative. In patients, in whom urinary excretion was above the reference limit, imaging studies with (123)I-MIBG (metaiodobenzylguanidine) scintigraphy and magnetic resonance imaging (MRI) and/or computed tomography (CT) were performed. Pheochromocytomas and extra-adrenal paragangliomas were treated surgically after appropriate blockade. Median follow-up was 4.5 years (range 0.5-19.5 years). Twenty-eight out of the 93 patients were included in our study and underwent additional imaging for pheochromocytomas/extra-adrenal paragangliomas. In 11 out of the 28 patients intra-adrenal pheochromocytomas were found. Extra-adrenal paragangliomas were discovered in eight patients. These tumors were detected during initial screening in 63% of cases, whereas 37% were detected after repeated biochemical screening. One patient was diagnosed with a biochemically silent pheochromocytoma. The high prevalence of pheochromocytomas/extra-adrenal paragangliomas in patients with SDHD-associated HNP warrants regular screening for tumors in these patients. Paragangliomas that do not secrete catecholamines might be more prevalent than previously reported. Future studies will have to establish whether routine imaging studies should be included in the screening of SDHD mutation carriers, irrespective of biochemical screening.

Reduced quality of life in patients with head-and-neck paragangliomas.

OBJECTIVE: The objective of this study was to assess the quality of life (QoL) in patients with head-and-neck paragangliomas ('glomus tumors'). DESIGN: We conducted a case-control study. METHODS: We assessed QoL in 82 patients with head-and-neck paragangliomas using four validated health-related questionnaires: Hospital Anxiety and Depression Scale, Multidimensional Fatigue Index (MFI-20), Short Form-36 (SF-36), and Nottingham Health Profile (NHP). Patient outcomes were compared with controls provided by the patients and with a large age- and sex-adjusted control group. RESULTS: The QoL scores in the paraganglioma patients were significantly reduced in 12 out of the 21 subscales compared with own controls, and in 18 out of the 21 subscales compared with age- and sex-adjusted values derived from the previous studies. In the MFI-20 questionnaire, patients reported more general fatigue, physical fatigue, mental fatigue, and a reduction in activity and motivation. The scores in the NHP showed a difference in energy, emotional reaction, and social isolation. General health perception, pain, and physical functioning were reported to be worse in the paraganglioma patients on the SF-36 scale. Although anxiety and depression did not reveal any significant differences between patients and their own controls, an increased score on both anxiety and depression was seen when compared with the extended control group. Especially, dysphonia contributes to a reduced QoL. CONCLUSION: QoL is considerably reduced in patients with head-and-neck paragangliomas.

Establishing a method to predict the outcome of vestibular schwannoma surgery based on one's own results.

OBJECTIVES: To establish a prognostication method based on our own results of vestibular schwannoma surgery. DESIGN: Retrospective data analysis. SETTING: Tertiary referral centre. PARTICIPANTS: 141 ambulatory patients operated for unilateral vestibular schwannoma by the translabyrinthine approach in the period 1996--2003. MAIN OUTCOME MEASURES: Facial impairment defined by House Brackmann grade III-VI, and the relation with tumor size. RESULTS: For our institution we found that in a range of tumor sizes the tumor size of 17.5 mm was the cut-off point associated with highest sensitivity and specificity values available concerning the prediction of facial impairment, these were 0.86 and 0.61. Compared to a random cut-off point (11 mm), this leads to 36% more accurate predictions. CONCLUSIONS: By establishing sensitivity and specificity values of predictions, one is aware of the rate of false predictions. By Receiver Operating Curve analysis the rate of false predictions can be minimised. In vestibular schwannoma surgery this leads to more precise predictions concerning outcome, as we have demonstrated for the facial function.

Translabyrinthine surgery for disabling vertigo in vestibular schwannoma patients.

OBJECTIVE: To determine the impact of translabyrinthine surgery on the quality of life in vestibular schwannoma patients with rotatory vertigo. STUDY DESIGN: Prospective study in 18 vestibular schwannoma patients. SETTING: The study was conducted in a multispecialty tertiary care clinic. PARTICIPANTS: All 18 patients had a unilateral intracanalicular vestibular schwannoma, without serviceable hearing in the affected ear and severely handicapped by attacks of rotatory vertigo and constant dizziness. Despite an initial conservative treatment, extensive vestibular rehabilitation exercises, translabyrinthine surgery was performed because of the disabling character of the vertigo, which considerably continued to affect the patients' quality of life. MAIN OUTCOME MEASURES: Preoperative and postoperative quality of life using the Short Form 36 Health Survey (Short Form-36) scores and Dizziness Handicap Inventory (DHI) scores. RESULTS: A total of 17 patients (94%) completed the questionnaire preoperatively and 3 and 12 months postoperatively. All Short Form-36 scales of the studied patients scored significantly lower when compared with the healthy Dutch control sample (P < 0.05). There was a significant improvement of DHI total scores and Short Form-36 scales on physical and social functioning, role-physical functioning, role-emotional functioning, mental health and general health at 12 months after surgery when compared with preoperative scores (P < 0.05). CONCLUSIONS: Vestibular schwannoma patients with disabling vertigo, experience significant reduced quality of life when compared with a healthy Dutch population. Translabyrinthine tumour removal significantly improved the patients' quality of life. Surgical treatment should be considered in patients with small- or medium-sized tumours and persisting disabling vertigo resulting in a poor quality of life.

Malignant paragangliomas associated with mutations in the succinate dehydrogenase D gene.

INTRODUCTION: Malignant paragangliomas have been well described in carriers of mutations of the succinate dehydrogenase B (SDHB) gene, but have rarely been associated with mutations in the succinate dehydrogenase D (SDHD) gene. AIM: The aim of the study was to report the different clinical expression patterns of malignant paragangliomas in five patients with SDHD (D92Y) mutations observed in approximately 200 SDHD (D92Y) mutation carriers followed in our institution. RESULTS: Metastasis and/or local tumor invasion was documented 0 (n=2), 1, 18, and 30 yr after the initial diagnosis of paraganglioma. Malignancy was proven by paraganglioma bone metastases (n=2), intrathoracic paraganglioma with lymph node metastases, locally invasive head-and-neck paraganglioma with destruction of the petrosal bone, and locally invasive paraganglioma of the bladder with lymph node metastases. Four of the five patients developed catecholamine excess during follow-up due to intraadrenal paraganglioma (pheochromocytoma) (n=1), extra adrenal paraganglioma (n=2), and presumed subclinical disease (n=1). CONCLUSION: SDHD mutations (D92Y) are associated with malignant paragangliomas and catecholamine excess with remarkable interindividual variations despite the same mutation. We estimate that the prevalence of malignancy in carriers of D92Y mutations is at least 2.5%.

Increased prevalence of catecholamine excess and phaeochromocytomas in a well-defined Dutch population with SDHD-linked head and neck paragangliomas.

OBJECTIVE: The aim of this study was to identify the prevalence of catecholamine excess and phaeochromocytomas in a well-defined population of people with hereditary head and neck paragangliomas. METHODS: We studied in a prospective follow-up protocol all consecutive patients referred to the Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands with documented head and neck paragangliomas and either a positive family history for paragangliomas or a proven SDHD gene mutation. Initial analysis included medical history, physical examination and the measurement of excretion of catecholamines in two 24-h urine collections. In the case of documented catecholamine excess iodinated meta-iodobenzylguanidine (123I-MIBG) scintigraphy and magnetic resonance imaging were done. RESULTS: Between 1988 and 2003, 40 consecutive patients (20 male and 20 female) with documented head and neck paragangliomas were screened. Biochemical screening revealed urinary catecholamine excess in 15 patients (37.5%). In nine of these 15 patients a lesion was found by 123I-MIBG scintigraphy. Exact localization by magnetic resonance imaging revealed phaeochromocytomas in seven of the 15 patients. One of the nine patients had an extra-adrenal paraganglioma. Histopathological examination in a subset of tumors displayed loss of heterozygosity of the wild-type SDHD allele in all cases. CONCLUSIONS: The prevalence of catecholamine excess (37.5%) and phaeochromocytomas (20.0%) is high in patients with familial head and neck paragangliomas. Therefore, patients with hereditary head and neck paragangliomas require lifelong follow up by biochemical testing for catecholamine excess.

SDHD mutations in head and neck paragangliomas result in destabilization of complex II in the mitochondrial respiratory chain with loss of enzymatic activity and abnormal mitochondrial morphology.

Hereditary head and neck paragangliomas are tumours associated with the autonomic nervous system. Recently, mutations in genes coding for subunits of mitochondrial complex II, succinate-ubiquinone-oxidoreductase (SDHB, SDHC, and SDHD), have been identified in the majority of hereditary tumours and a number of isolated cases. In addition, a fourth locus, PGL2, has been mapped to chromosome 11q13 in an isolated family. In order to characterize phenotypic effects of these mutations, the present study investigated the immunohistochemical expression of the catalytic subunits of complex II (flavoprotein and iron protein), SDH enzyme activity, and mitochondrial morphology in a series of 22 head and neck paragangliomas. These included 11 SDHD-, one SDHB-, two PGL2-linked tumours, and eight sporadic tumours. In the majority of the tumours (approximately 90%), the enzyme-histochemical SDH reaction was negative and immunohistochemistry of catalytic subunits of complex II showed reduced expression of iron protein and enhanced expression of flavoprotein. Ultrastructural examination revealed elevated numbers of tightly packed mitochondria with abnormal morphology in SDHD-linked and sporadic tumours. Immuno-electron microscopy showed localization of the flavoprotein on the remnants of the mitochondrial inner membranes, whereas virtually no signal for the iron protein was detected. These results indicate that the function of mitochondrial complex II is compromised in the majority of head and neck paragangliomas.

[From gene to disease; from SDHD, a defect in the respiratory chain, to paragangliomas and pheochromocytomas]. / Van gen naar ziekte; van SDHD, een defect in de ademhalingsketen, naar paragangliomen en feochromocytomen.

Hereditary paragangliomas are rare benign tumours arising from neuroectodermal tissue in the head and neck region. In families with paraganglioma, occasionally adrenal and extra-adrenal pheochromocytomas are found. Paragangliomas, adrenal and extra-adrenal pheochromocytomas may be caused by mutations in the SDHB, SDHC and SDHD genes encoding different subunits of mitochondrial respiratory chain complex II. Most paraganglioma cases in the Netherlands are caused by SDHD mutations. Presymptomatic DNA diagnosis is available for families with paragangliomas caused by SDHD mutations.

Management of carotid body tumors.

The carotid body tumor is a rare neoplasm that has generated much literature over the past century, and for which continued controversy exists regarding natural history, biologic behavior, proper technique of excision, and the risk of morbidity and mortality. This article discusses overall management of carotid body tumors.

Nearly all hereditary paragangliomas in the Netherlands are caused by two founder mutations in the SDHD gene.

Hereditary paragangliomas or glomus tumors are usually benign slow-growing tumors in the head and neck region. The inheritance pattern of hereditary paraganglioma is autosomal dominant with imprinting. Recently, we have identified the SDHD gene encoding subunit D of the mitochondrial respiratory chain complex II as one of the genes involved in hereditary paragangliomas. Here, we demonstrate that two founder mutations, Asp92Tyr and Leu139Pro, are responsible for paragangliomas in 24 and 6 of the 32 independently ascertained Dutch paraganglioma families, respectively. These two mutations were also detected among 20 of 55 isolated patients. Ten of the isolated patients had multiple paragangliomas, and in eight of these SDHD germline mutations were found, indicating that multicentricity is a strong predictive factor for the hereditary nature of the disorder in isolated patients. In addition, we demonstrate that the maternally derived wild-type SDHD allele is lost in tumors from mutation-carrying patients, indicating that SDHD functions as a tumor suppressor gene.

Estimation of growth rate in patients with head and neck paragangliomas influences the treatment proposal.

BACKGROUND: Extraadrenal paragangliomas of the head and neck are tumors with variable clinical behavior. Because tumor growth as well as surgery can cause disabling loss of function, knowledge of the natural history of paragangliomas is important for the development of treatment strategies. METHODS: The tumor volume, growth rate, and tumor doubling time of 48 paragangliomas at different anatomic locations in the head and neck region were estimated retrospectively using sequential radiologic imaging. RESULTS: During a mean follow-up period of 4.2 years, a volume increase of > 20% was observed in 60% of the paragangliomas. In these cases the median growth rate was 1.0 mm/year and the median tumor doubling time was 4. 2 years. More growing tumors were observed in intermediate size tumors than in very small or large paragangliomas, suggesting a biphasic growth pattern. CONCLUSIONS: The majority of head and neck paragangliomas have a very low growth rate. Although management of paragangliomas also is determined by other parameters, preoperative estimation of the tumor doubling time may influence the treatment proposal. A "wait and scan" policy must be considered in all cases.