Increased Mortality in SDHB but Not in SDHD Pathogenic Variant Carriers.

Germline mutations in succinate dehydrogenase subunit B and D (SDHB and SDHD) are predisposed to hereditary paraganglioma (PGL) and pheochromocytoma (PHEO). The phenotype of pathogenic variants varies according to the causative gene. In this retrospective study, we estimate the mortality of a nationwide cohort of SDHB variant carriers and that of a large cohort of SDHD variant carriers and compare it to the mortality of a matched cohort of the general Dutch population. A total of 192 SDHB variant carriers and 232 SDHD variant carriers were included in this study. The Standard Mortality Ratio (SMR) for SDHB mutation carriers was 1.89, increasing to 2.88 in carriers affected by PGL. For SDHD variant carriers the SMR was 0.93 and 1.06 in affected carriers. Compared to the general population, mortality seems to be increased in SDHB variant carriers, especially in those affected by PGL. In SDHD variant carriers, the mortality is comparable to that of the general Dutch population, even if they are affected by PGL. This insight emphasizes the significance of DNA-testing in all PGL and PHEO patients, since different clinical risks may warrant gene-specific management strategies.

The phenotype of SDHB germline mutation carriers: a nationwide study.

OBJECTIVE: Succinate dehydrogenase B subunit (SDHB) gene germline mutations predispose to pheochromocytomas, sympathetic paragangliomas, head and neck paragangliomas and non-paraganglionic tumors (e.g. renal cell carcinoma, gastrointestinal stromal tumor and pituitary neoplasia). The aim of this study was to determine phenotypical characteristics of a large Dutch cohort of SDHB germline mutation carriers and assess differences in clinical phenotypes related to specific SDHB mutations. DESIGN: Retrospective descriptive study. METHODS: Retrospective descriptive study in seven academic centers. RESULTS: We included 194 SDHB mutation carriers consisting 65 (33.5%) index patients and 129 (66.5%) relatives. Mean age was 44.8 ± 16.0 years. Median duration of follow-up was 2.6 years (range: 0-36). Sixty persons (30.9%) carried the exon 3 deletion and 46 (23.7%) the c.423 + 1G > A mutation. Fifty-four mutation carriers (27.8%) had one or multiple head and neck paragangliomas, 4 (2.1%) had a pheochromocytoma and 26 (13.4%) had one or more sympathetic paragangliomas. Fifteen patients (7.7%) developed metastatic paraganglioma and 17 (8.8%) developed non-paraganglionic tumors. At study close, there were 111 (57.2%) unaffected mutation carriers. Statistical analyses showed no significant differences in the number and location of head and neck paragangliomas, sympathetic paragangliomas or pheochromocytomas, nor in the occurrence of metastatic disease or other tumors between carriers of the two founder SDHB mutations (exon 3 deletion vs c.423 + 1G > A). CONCLUSIONS: In this nationwide study of disease-affected and unaffected SDHB mutation carriers, we observed a lower rate of metastatic disease and a relatively high number of head and neck paragangliomas compared with previously reported referral-based cohorts.

Succinate Dehydrogenase (SDH)-Deficient Pancreatic Neuroendocrine Tumor Expands the SDH-Related Tumor Spectrum.

CONTEXT: Mutations in genes encoding the subunits of succinate dehydrogenase (SDH) can lead to pheochromocytoma/paraganglioma formation. However, SDH mutations have also been linked to nonparaganglionic tumors. OBJECTIVE: The objective was to investigate which nonparaganglionic tumors belong to the SDH-associated tumor spectrum. DESIGN: This was a retrospective cohort study. SETTING: The setting was a tertiary referral center. PATIENTS: Patients included all consecutive SDHA/SDHB/SDHC and SDHD mutation carriers followed at the Department of Endocrinology of the Leiden University Medical Center who were affected by non-pheochromocytoma/paraganglioma solid tumors. MAIN OUTCOME MEASURES: Main outcome measures were SDHA/SDHB immunohistochemistry, mutation analysis, and loss of heterozygosity analysis of the involved SDH-encoding genes. RESULTS: Twenty-five of 35 tumors (from 26 patients) showed positive staining on SDHB and SDHA immunohistochemistry. Eight tumors showed negative staining for SDHB and positive staining for SDHA: a pancreatic neuroendocrine tumor, a macroprolactinoma, two gastric gastrointestinal stromal tumors, an abdominal ganglioneuroma, and three renal cell carcinomas. With the exception of the abdominal ganglioneuroma, loss of heterozygosity was detected in all tumors. A prolactinoma in a patient with a germline SDHA mutation was the only tumor immunonegative for both SDHA and SDHB. Sanger sequencing of this tumor revealed a somatic mutation (p.D38V) as a likely second hit leading to biallelic inactivation of SDHA. One tumor (breast cancer) showed heterogeneous SDHB staining, positive SDHA staining, and retention of heterozygosity. CONCLUSIONS: This study strengthens the etiological association of SDH genes with pituitary neoplasia, renal tumorigenesis, and gastric gastrointestinal stromal tumors. Furthermore, our results indicate that pancreatic neuroendocrine tumor also falls within the SDH-related tumor spectrum.

Sleep-mediated heart rate variability after bilateral carotid body tumor resection.

STUDY OBJECTIVES: The carotid bodies are thought to play an important role in sleep-dependent autonomic changes. Patients who underwent resection of bilateral carotid body tumors have chronically attenuated baroreflex sensitivity. These subjects provide a unique opportunity to investigate the role of the baroreflex during sleep. DESIGN: One-night ambulatory polysomnography (PSG) recording. SETTING: Participants' homes. PARTICIPANTS: Nine patients with bilateral carotid body tumor resection (bCBR) (four women, mean age 50.4 ± 7.2 years) and nine controls matched for age, gender, and body mass index. INTERVENTIONS: N/A. MEASUREMENTS: Sleep parameters were obtained from PSG. Heart rate (HR) and its variability were calculated using 30-s epochs. RESULTS: In bCBR patients, HR was slightly but not significantly increased during wake and all sleep stages. The effect of sleep on HR was similar for patients and controls. Low frequency (LF) power of the heart rate variability spectrum was significantly lower in bCBR patients in active wakefulness, sleep stage 1 and REM sleep. No differences were found between patients and controls for high frequency (HF) power and the LF/HF ratio. CONCLUSIONS: Bilateral carotid body tumor resection (bCBR) is associated with decreased low frequency power during sleep, suggesting impaired baroreflex function. Despite this, sleep-related heart rate changes were similar between bCBR patients and controls. These findings suggest that the effects of sleep on heart rate are predominantly generated through central, non-baroreflex mediated pathways.

Towards a better quality of life (QoL) for patients with pituitary diseases: results from a focus group study exploring QoL.

PURPOSE: Patients treated for pituitary adenomas generally report a reduced quality of life (QoL). At present, the patient's perspective of QoL has not been fully addressed and this, and further insight in potential determinants of QoL in pituitary diseases is required to design strategies to improve QoL. We aimed to define patients' perceived QoL and to identify potential factors they perceive to contribute to QoL. METHODS: We conducted four independent focus groups of six patients each, per specific pituitary disease (Cushing's disease, Non-functioning pituitary macroadenoma, acromegaly, prolactinoma). In two sessions these focus groups discussed aspects of QoL. Verbatim transcripts were analyzed using a grounded theory approach. RESULTS: The issues raised by the patient groups were compatible with statements and items of available QoL questionnaires. In addition, other QoL aspects emerged, such as visual limitations (physical problems); issues with a desire to have children/family planning, fear of collapsing, fear of recurrence, panic, persisting thoughts, problems with an altered personality, anger, jealousy, sadness, frustration (psychological problems); and difficulties communicating about the disease, lack of sympathy and understanding by others, and a reduced social network (social problems). Next, this study uncovered factors which might contribute to a decreased QoL (e.g. less effective coping strategies, negative illness perceptions, negative beliefs about medicines, unmet needs regarding care). CONCLUSIONS: This focus group study demonstrated that important disease-specific aspects of QoL are neglected in current pituitary disease-specific questionnaires and elucidated potential factors that contribute to a decreased QoL. Information provided in this study can (and will) be used for developing additional items for disease-specific QoL questionnaires and for the development of a self-management intervention aiming to improve QoL in patients treated for pituitary diseases.

Succinate dehydrogenase (SDH)-deficient renal carcinoma: a morphologically distinct entity: a clinicopathologic series of 36 tumors from 27 patients.

Succinate dehydrogenase (SDH)-deficient renal carcinoma has been accepted as a provisional entity in the 2013 International Society of Urological Pathology Vancouver Classification. To further define its morphologic and clinical features, we studied a multi-institutional cohort of 36 SDH-deficient renal carcinomas from 27 patients, including 21 previously unreported cases. We estimate that 0.05% to 0.2% of all renal carcinomas are SDH deficient. Mean patient age at presentation was 37 years (range, 14 to 76 y), with a slight male predominance (M:F=1.7:1). Bilateral tumors were observed in 26% of patients. Thirty-four (94%) tumors demonstrated the previously reported morphology at least focally, which included: solid or focally cystic growth, uniform cytology with eosinophilic flocculent cytoplasm, intracytoplasmic vacuolations and inclusions, and round to oval low-grade nuclei. All 17 patients who underwent genetic testing for mutation in the SDH subunits demonstrated germline mutations (16 in SDHB and 1 in SDHC). Nine of 27 (33%) patients developed metastatic disease, 2 of them after prolonged follow-up (5.5 and 30 y). Seven of 10 patients (70%) with high-grade nuclei metastasized as did all 4 patients with coagulative necrosis. Two of 17 (12%) patients with low-grade nuclei metastasized, and both had unbiopsied contralateral tumors, which may have been the origin of the metastatic disease. In conclusion, SDH-deficient renal carcinoma is a rare and unique type of renal carcinoma, exhibiting stereotypical morphologic features in the great majority of cases and showing a strong relationship with SDH germline mutation. Although this tumor may undergo dedifferentiation and metastasize, sometimes after a prolonged delay, metastatic disease is rare in the absence of high-grade nuclear atypia or coagulative necrosis.

Löffler endocarditis: a rare cause of acute cardiac failure.

We describe a patient with acute cardiogenic shock due to cardiac involvement in idiopathic hypereosinophilic syndrome (Löffler endocarditis). At the echocardiography, there was a huge mass in the left ventricular cavity, resulting in inflow- and outflow tract obstruction. The posterior leaflet of the mitral valve apparatus was completely embedded in a big (organized) thrombus mass. The patient was treated with high dose corticosteroids, however without effect. Partial remission was achieved after treatment with hydroxycarbamide. He was also treated with anticoagulants and high dose beta-blockers. The patient's condition improved remarkably after correction of the mitral valve insufficiency by a mitral valve bioprosthesis.

Symptomatic hypocalcemia after sodium phosphate preparation in an adult with asymptomatic hypoparathyroidism.

Sodium phosphate is widely used as a bowel cleansing preparation. Its use is, however, not without risk. It can induce serious adverse effects like hypocalcemia, hyperphosphatemia and renal failure. In this case, a 75-year-old woman without known contraindications developed hypocalcemic tetany, hyperphosphatemia and renal failure after oral sodium phosphate. Asymptomatic hypoparathyroidism owing to previous thyroid surgery was identified as a new contributing risk factor for this complication.