Hypoxia-Inducible Factor 2α Mutation-Related Paragangliomas Classify as Discrete Pseudohypoxic Subcluster.

Recently, activating mutations of the hypoxia-inducible factor 2α gene (HIF2A/EPAS1) have been recognized to predispose to multiple paragangliomas (PGLs) and duodenal somatostatinomas associated with polycythemia, and ocular abnormalities. Previously, mutations in the SDHA/B/C/D, SDHAF2, VHL, FH, PHD1, and PHD2 genes have been associated with HIF activation and the development of pseudohypoxic (cluster-1) PGLs. These tumors overlap in terms of tumor location, syndromic presentation, and noradrenergic phenotype to a certain extent. However, they also differ especially by clinical outcome and by presence of other tumors or abnormalities. In the present study, we aimed to establish additional molecular differences between HIF2A and non-HIF2A pseudohypoxic PGLs. RNA expression patterns of HIF2A PGLs (n=6) from 2 patients were compared with normal adrenal medullas (n=8) and other hereditary pseudohypoxic PGLs (VHL: n=13, SDHB: n=15, and SDHD: n=14). Unsupervised hierarchical clustering showed that HIF2A PGLs made up a separate cluster from other pseudohypoxic PGLs. Significance analysis of microarray yielded 875 differentially expressed genes between HIF2A and other pseudohypoxic PGLs after normalization to adrenal medulla (false discovery rate 0.01). Prediction analysis of microarray allowed correct classification of all HIF2A samples based on as little as three genes (TRHDE, LRRC63, IGSF10; error rate: 0.02). Genes with the highest expression difference between normal medulla and HIF2A PGLs were selected for confirmatory quantitative reverse transcriptase polymerase chain reaction. In conclusion, HIF2A PGLs show a characteristic expression signature that separates them from non-HIF2A pseudohypoxic PGLs. Unexpectedly, the most significantly differentially expressed genes have not been previously described as HIF target genes.

Fascin upregulation in primary head and neck squamous cell carcinoma is associated with lymphatic metastasis.

Fascin is an actin-bundling protein that is associated with cellular motility and cancer-cell invasion. The present study aimed to examine the expression of fascin in head and neck squamous cell carcinoma (HNSCC) and its potential use as a biomarker. In a prospective study with a median follow-up time of 48.8 months, tumor tissues, adjacent healthy tissues and cervical lymph node metastases were collected from 25 patients and analyzed by immunohistochemistry. The specimens were scored according to the intensity of fascin staining and the percentage of tumor cells stained using a semi-quantitative scoring approach; the data were analyzed and correlated with clinical follow-up observations. All of the investigators were blinded to the origin of the specimens. The expression levels of fascin were significantly increased in the tumor tissues (P=0.03) and lymph node metastases (P=0.03) compared with that of the normal tissues. The high expression level of fascin in the tumor tissues was correlated with the N-status, however, not with overall survival. Therefore, fascin may be a suitable marker for the prediction of regional lymphatic metastasis in HNSCC.

Phenotypic variability and risk of malignancy in SDHC-linked paragangliomas: lessons from three unrelated cases with an identical germline mutation (p.Arg133*).

CONTEXT: Mutations in the four subunits of succinate dehydrogenase (SDH) are the cause for the hereditary paraganglioma (PGL) syndrome types 1-4 and are associated with multiple and recurrent pheochromocytomas and PGLs. SDHC mutations most frequently result in benign, nonfunctional head-and neck PGLs (HNPGLs). The malignant potential of SDHC mutations remains unclear to date. OBJECTIVES: We report a patient with malignant PGL carrying a SDHC mutation and compare her case with two others of the same genotype but presenting with classic benign HNPGLs. Loss of heterozygosity (LOH) was demonstrated in the malignant PGL tissue. DESIGN: In three unrelated patients referred for routine genetic testing, SDHB, SDHC, and SDHD genes were sequenced, and gross deletions were excluded by multiplex ligation-dependent probe amplification (MLPA). LOH was determined by pyrosequencing-based allele quantification and SDHB immunohistochemistry. RESULTS: In a patient with a nonfunctioning thoracic PGL metastatic to the bone, the lungs, and mediastinal lymph nodes, we detected the SDHC mutation c.397C>T predicting a truncated protein due to a premature stop codon (p.Arg133*). We demonstrated LOH and loss of SDHB protein expression in the malignant tumor tissue. The two other patients also carried c.397C>T, p.Arg133*; they differed from each other with respect to their tumor characteristics, but both showed benign HNPGLs. CONCLUSIONS: We describe the first case of a malignant PGL with distant metastases caused by a SDHC germline mutation. The present case shows that SDHC germline mutations can have highly variable phenotypes and may cause malignant PGL, although malignancy is probably rare.

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.

Malignant and benign sinonasal paragangliomas.

OBJECTIVES/HYPOTHESIS: To report on the clinical course and management of sinonasal paragangliomas (PGLs). STUDY DESIGN AND METHODS: Retrospective chart review of six patients with PGLs of the nasal cavity and paranasal sinuses. RESULTS: Three patients had tumors with malignant clinical behavior with cerebral metastases or infiltration of brain and local recurrence, despite surgery and/or radiotherapy, while three patients demonstrated a benign course. CONCLUSION: Sinonasal paragangliomas are frequently malignant. If malignant, they are very aggressive, with rapid local spread as well as high metastatic potential despite surgical resection; and they have a poor prognosis. Malignancy cannot be diagnosed on histology, but only on the basis of clinical behavior. Intracranial metastasis is commonly expected. Long-term follow-up, with particular emphasis put on the intracranial structures, is mandatory as recurrences or metastasis may occur even after a long time interval.

High incidence of extraadrenal paraganglioma in families with SDHx syndromes detected by functional imaging with [18F]fluorodihydroxyphenylalanine PET.

PURPOSE: Knowledge of the genetic backgrounds of hereditary syndromes, which are increasingly being characterized, enables genetic screening of family members of affected patients. Upon detection of a mutation, genetic counselling and clinical screening including imaging modalities and biochemical analyses are commonly performed. METHODS: Unaffected, mutation-positive relatives of index patients with hereditary paraganglioma syndromes were offered PET imaging with [(18)F]fluorodihydroxyphenylalanine and the incidence of pathological findings was retrospectively analysed in relation to mutations of the succinate dehydrogenase enzyme complex. PET only or PET/CT was performed in 21 individuals from eight families with SDHD, one family with SDHC and two families with SDHB mutations. Screening was offered every 2 to 5 years. RESULTS: Of the 21 individuals, 14 showed paraganglioma during screening. In particular, in only 2 of 15 patients with a SDHD mutation were the findings completely unremarkable on PET screening. However, false-negative lesions for abdominal manifestations in two SDHD-positive patients were detected. CONCLUSION: FDOPA PET is a sensitive imaging modality which should be offered to patients with a detected SDHx (SDHD) mutation, preferably using a hybrid technique.

Head and neck paragangliomas: Report of 175 patients (1989-2010).

BACKGROUND: Attention of the otorhinolaryngologist needs to be drawn to the versatile aspects of head and neck paragangliomas (PGLs). METHODS: This study is a retrospective, nonrandomized clinical study of all 175 individuals with PGLs treated in our department between 1989 and 2010. A genetic analysis was performed on 86 patients. RESULTS: The 175 patients presented 224 head and neck PGLs as well as 2 thyroid papillary carcinomas. Genetic analysis resulted in 1 patient positive for a von Hippel-Lindau (VHL) gene mutation and 34 for succinate dehydrogenase (SDH) gene mutations (22 SDHD, 7 SDHC, and 5 SDHB), 12 of the latter carrying a novel mutation. Thirty-three patients (18.9%) had multiple PGLs and 11 patients (6.3%) had a malignant paraganglioma. SDH-mutation carriers had multiple tumors in 64.7% and malignant paragangliomas in 20.6%. CONCLUSIONS: Multifocal occurrence, potential malignancy, genetic aspects, possible coincidence of thyroid carcinoma, and hormone production have to be considered in patients with head and neck PGLs.

Hearing results after hypotympanotomy for glomus tympanicum tumors.

OBJECTIVE: We postulate, that glomus tympanicum tumors (GTTs) may be safely removed without interference with the ossicular chain via a hypotympanotomy approach. STUDY DESIGN: Prospective, nonrandomized anatomic and clinical study. SETTING: Tertiary referral center. PATIENTS: All 17 patients between 1989 and 2009 with GTTs without involvement of the lumen of the jugular bulb. INTERVENTIONS: We used a modified hypotympanotomy approach. Our technique is a modification of the one first published by Shambaugh (1955). Pure-tone audiograms were performed in all patients. Preoperative and postoperative audiograms were modeled in a linear mixed model evaluating hearing threshold for air and bone conduction and air-bone gap at 500, 1,000, 2,000, and 3,000 Hz. In an effort to preserve the normal sound conducting apparatus and hearing, we used a retroauricular approach, exposing widely the jugular bulb, the carotid artery, the protympanum, and even the bony part of the Eustachian tube via a hypotympanotomy. Three formalin-fixed and one macerated temporal bones were dissected step by step under the operating microscope to demonstrate the approach in cadaver dissections. MAIN OUTCOME MEASURE: To evaluate if GTTs can be completely resected without interference with the ossicular chain to improve conductive hearing loss. RESULTS: We found a substantial improvement of hearing threshold after surgery at all frequencies in air conduction. For bone conduction, there was only a slight gain within random variation. The air-bone gap decreased significantly after surgery. CONCLUSION: Our approach demonstrated a safe avenue for complete tumor removal without interference with the continuity of the ossicular chain.

Branchial cleft cysts in adults. Diagnostic procedures and treatment in a series of 18 cases.

PURPOSE: Branchial cleft anomalies may be presented as branchial cysts, fistulas, or sinuses. Purpose of this paper is to present the diagnostic procedures and the treatment in a series of branchial cleft cysts. METHODS: Eighteen patients with branchial cleft cysts were surgically treated. All of them were subjected in laboratory examinations with ultrasonography, CT or/and MRI, and fine needle aspiration cytology (FNAC). Complete excision was the treatment in all cases. RESULTS: Eight patients had Type I, seven Type II, two Type III, and one a Type IV cyst. In all cases the surgical removal was successful and after 1 to 7 years post-surgical follow-up, no recurrences have been developed. CONCLUSIONS: Branchial cleft cyst diagnostic procedure must be the same as for other neck swellings. FNAC is very useful for the diagnosis and the surgical approach must ensure safe and complete cyst removal in order to avoid intraoperative complications and recurrences.

Management of head and neck paragangliomas: review of 120 patients.

BACKGROUND: Head and neck paragangliomas (PGL) are rare, mostly benign tumors. About 10% to 15% of PGL are caused by mutations in the succinate dehydrogenase genes B, C, or D and may appear multifocally. METHODS AND RESULTS: A retrospective review of 120 patients with 146 head and neck PGL, including 46 carotid body tumors (CBT), 13 vagal tumors, 55 jugulotympanic tumors (JTT), 25 tympanic tumors (TT) and 7 tumors in other locations are included. The internal carotid artery was preserved in 97.5% of CBT resections. Preservation of hearing was achieved in 92% of JTT and 88% of TT resections. CONCLUSION: According to our experience, the treatment of PGL must be individualized, taking into account the patient's age, medical condition, tumor site and size, multiple occurrences, and preexisting cranial nerve deficits. Tumor control is high whether treatment is by surgery or radiotherapy. Patients with solitary lesions whose disease is potentially resectable with acceptable morbidity are better treated surgically.

Malignant paraganglioma caused by a novel germline mutation of the succinate dehydrogenase D-gene--a case report.

BACKGROUND: Paragangliomas of the head and neck are rare, mostly benign tumors. Approximately 10% to 15% of paragangliomas are caused by mutations in the succinate dehydrogenase (SDH) genes B, C, or D. These are often multifocal as part of paraganglioma syndromes and hormone secreting, and malignant particularly associated with mutations in SDHB. METHODS AND RESULTS: A 29-year-old man was seen with recurrent paraganglioma. The patient's father reportedly suffered from bilateral carotid body tumors. Imaging studies showed metastases in both lungs and the liver. There was no increased hormone production by the tumor. Sequence analysis of the SDH genes revealed a novel C to T nonsense mutation in the first exon of the SDHD gene (R17X). CONCLUSIONS: A novel mutation in the SDHD gene associated with malignant paraganglioma is reported. This case underscores the relevance of family history and genetic analysis, thus permitting early detection of unaffected carriers. These have to be monitored clinically, biochemically and by imaging techniques.