Pheochromocytomas detected by biochemical screening in predisposed subjects are associated with lower prevalence of clinical and biochemical manifestations and smaller tumors than pheochromocytomas detected by signs and symptoms

Phaeochromocytoma and paraganglioma

Phaeochromocytomas and paragangliomas are rare catecholamine-producing neuroendocrine tumours which can potentially cause catastrophic crises with high morbidity and mortality. This best practice article considers the causes and presentation of such tumours, screening and diagnostic tests, management of these patients and consideration of family members at risk.

Pheochromocytoma/paraganglioma crisis: case series from a tertiary referral center for pheochromocytomas and paragangliomas

Pheochromocytoma/paraganglioma (PPGL)-induced catecholamine crisis is a rare endocrine emergency leading to life-threatening hemodynamic instability causing end-organ damage or dysfunction. As it is associated with a significant mortality rate of approximately 15%, recognizing the signs and symptoms and making the appropriate diagnosis are critical. For this purpose, we report the clinical course of the crisis in four out of a total of six patients with a PPGL crisis from a cohort of 199 PPGL patients of a single tertiary referral center for PPGL patients in the Netherlands diagnosed between 2002 and 2020. Successful treatment of a PPGL crisis demands prompt diagnosis, vigorous pharmacological therapy, and emergency tumor removal if the patient continues to deteriorate.

Does this patient have pheochromocytoma? A systematic review of clinical signs and symptoms

Context

Pheochromocytoma is a rare disease but with high mortality if it is not being diagnosed early. Several biochemical tests with high accuracy have been obtained, but the clinical threshold for request of these tests is not determined clearly.

Objectives

To determine the Likelihood Ratios of clinical symptoms and signs in diagnosing pheochromocytoma. And also meta-analysis of their sensitivity in this disease.

Data sources

MEDLINE was searched for relevant English-language articles dated 1960 to February 2014. Bibliographies were searched to find additional articles.

Study selection

We included original studies describing the sensitivity and/or likelihood ratios of signs and symptoms in clinical suspicion of pheochromocytoma. Their method of diagnosis should have been based on pathology. We excluded specific subtypes or syndromes related to pheochromocytoma, or specific ages or gender. Also we excluded studies before 1993 (JNC5) which no definition of hypertension was presented. 37 articles were chosen finally.

Data extraction

Two authors reviewed data from articles independently and gave discrepancies to third author for decision. The aim was extraction of raw numbers of patients having defined signs or symptoms, and draw 2 × 2 tables if data available. We meta-analyzed sensitivities by Statsdirect and Likelihood Ratios by Meta-disc soft wares. Because our data was heterogeneous based on I² > 50 % (except negative Likelihood ratio of hypertension), we used random effect model for doing meta-analysis. We checked publication bias by drawing Funnel plot for each sign/symptom, and also Egger test.

Data synthesis

The most prevalent signs and symptoms reported were hypertension (pooled sensitivity of 80.7 %), headache (pooled sensitivity of 60.4 %), palpitation (pooled sensitivity of 59.3 %) and diaphoresis (pooled sensitivity of 52.4 %). The definition of orthostatic hypotension was different among studies. The sensitivity was 23–50 %.

Paroxysmal hypertension, chest pain, flushing, and weakness were the signs/symptoms which had publication bias based on Funnel plot and Egger test (P value < 0.05). Seven of the articles had control group, and could be used for calculating LR of signs/symptoms. Diaphoresis (LR+ 2.2, LR- 0.45), Palpitation (LR+ 1.9, LR- 0.52) and headache (LR+ 1.6, LR- 0.24) were significant symptoms in clinical diagnosis of pheochromocytoma. Other signs and symptoms had been reported in only one study and could not have been meta-analyzed. Classic triad of headache, palpitation and diaphoresis in hypertensive patients had the LR+ 6.312 (95 % CI 0.217–183.217) and LR- 0.139 (95 % CI 0.059–0.331). Surprisingly, hypertension was not important in clinical suspicion of pheochromocytoma, and even normotension increased the probability of the disease.

Conclusions

By available data, there is no single clinical finding that has significant value in diagnosis or excluding pheochromocytoma. Combination of certain symptoms, signs and para-clinical exams is more valuable for physicians. Further studies should be done, to specify the value of clinical findings. Until that time the process of diagnosis will be based on clinical suspicion and lab tests followed by related imaging.

Does this patient have Pheochromocytoma? a systematic review of clinical signs and symptoms

Context

Pheochromocytoma is a rare disease but with high mortality if it is not being diagnosed early. Several biochemical tests with high accuracy have been obtained, but the clinical threshold for request of these tests is not determined clearly.

Objectives

To determine the Likelihood Ratios of clinical symptoms and signs in diagnosing pheochromocytoma. And also meta-analysis of their sensitivity in this disease.

Data sources

MEDLINE was searched for relevant English-language articles dated 1960 to February 2014. Bibliographies were searched to find additional articles.

Study selection

We included original studies describing the sensitivity and/or likelihood ratios of signs and symptoms in clinical suspicion of pheochromocytoma. Their method of diagnosis should have been based on pathology. We excluded specific subtypes or syndromes related to pheochromocytoma, or specific ages or gender. Also we excluded studies before 1993 (JNC5) which no definition of hypertension was presented. 37 articles were chosen finally.

Data extraction

Two authors reviewed data from articles independently and gave discrepancies to third author for decision. The aim was extraction of raw numbers of patients having defined signs or symptoms, and draw 2 × 2 tables if data available. We meta-analyzed sensitivities by Statsdirect and Likelihood Ratios by Meta-disc soft wares. Because our data was heterogeneous based on I² > 50 % (except negative Likelihood ratio of hypertension), we used random effect model for doing meta-analysis. We checked publication bias by drawing Funnel plot for each sign/symptom, and also Egger test.

Data synthesis

The most prevalent signs and symptoms reported were hypertension (pooled sensitivity of 80.7 %), headache (pooled sensitivity of 60.4 %), palpitation (pooled sensitivity of 59.3 %) and diaphoresis (pooled sensitivity of 52.4 %). The definition of orthostatic hypotension was different among studies. The sensitivity was 23–50 %.

Paroxysmal hypertension, chest pain, flushing, and weakness were the signs/symptoms which had publication bias based on Funnel plot and Egger test (P value < 0.05). Seven of the articles had control group, and could be used for calculating LR of signs/symptoms. Diaphoresis (LR+ 2.2, LR-0.45), Palpitation (LR+ 1.9, LR-0.52) and headache (LR+ 1.6, LR-0.24) were significant symptoms in clinical diagnosis of pheochromocytoma. Other signs and symptoms had been reported in only one study and could not have been meta-analyzed. Classic triad of headache, palpitation and diaphoresis in hypertensive patients had the LR+ 6.312 (95 % CI 0.217–183.217) and LR-0.139 (95 % CI 0.059–0.331). Surprisingly, hypertension was not important in clinical suspicion of pheochromocytoma, and even normotension increased the probability of the disease.

Conclusions

By available data, there is no single clinical finding that has significant value in diagnosis or excluding pheochromocytoma. Combination of certain symptoms, signs and para-clinical exams is more valuable for physicians. Further studies should be done, to specify the value of clinical findings.Until that time the process of diagnosis will be based on clinical suspicion and lab tests followed by related imaging.

No evidence for increased mortality in SDHD variant carriers compared with the general population

Germline variants in subunit D of the succinate dehydrogenase gene (SDHD variants) are associated with an increased risk of developing paragangliomas. The aim of this study was to compare mortality rates and survival in a Dutch cohort of SDHD variant carriers with those in the general population. The study was conducted at the Leiden University Medical Center, a tertiary referral center for patients with paragangliomas. Included subjects all tested positive for SDHD variants before 1 July 2012 and visited the departments of Otorhinolaryngology or Endocrinology at least once or had a diagnosed paraganglioma and a SDHD variant-positive family history. Clinical data were retrieved from medical records, information on mortality was obtained from the Municipal Personal Records Database, and mortality rates for the Dutch population were obtained from the Dutch Central Bureau of Statistics, stratified by sex, age and date. SDHD variant carriers were followed from the date of first SDHD variant-related contact until death, emigration or 12 December 2012 and the standardized mortality ratio (SMR) was calculated. Two-hundred and seventy-five SDHD variant carriers were included in the study, of which 80% carried the c.274G>T, p.(Asp92Tyr) variant, had a mean duration of follow-up of 7.6 years, yielding 2242 person-years of observation for analysis. There were 18 deaths in the SDHD variant carrier group; two were paraganglioma related. The SMR for the whole cohort was 1.07 (95% confidence interval 0.67-1.73). In conclusion, mortality in SDHD variant carriers is not substantially increased. Additional studies are required to confirm these findings.

Clinical management of paragangliomas

Paragangliomas (PGLs) are rare vascular, neuroendocrine tumors of paraganglia, which are associated with either sympathetic tissue in adrenal (pheochromocytomas (PCCs)) and extraadrenal (sympathetic paraganglioma (sPGLs)) locations or parasympathetic tissue of the head and neck paragangliomas (HNPGLs). As HNPGLs are usually benign and most tumors grow slowly, a wait-and-scan policy is often advised. However, their location in the close proximity to cranial nerves and vasculature may result in considerable morbidity due to compression or infiltration of the adjacent structures, necessitating balanced decisions between a wait-and-see policy and active treatment. The main treatment options for HNPGL are surgery and radiotherapy. In contrast to HNPGLs, the majority of sPGL/PCCs produces catecholamines, in advanced cases resulting in typical symptoms and signs such as palpitations, headache, diaphoresis, and hypertension. The state-of-the-art diagnosis and localization of sPGL/PCCs are based on measurement of plasma and/or 24-h urinary excretion of (fractionated) metanephrines and methoxytyramine (MT). sPGL/PCCs can subsequently be localized by anatomical (computed tomography and/or magnetic resonance imaging) and functional imaging studies (123I-metaiodobenzylguanidine-scintigraphy, 111In-pentetreotide scintigraphy, or positron emission tomography with radiolabeled dopamine or dihydroxyphenylalanine). Although most PGL/PCCs are benign, factors such as genetic background, tumor size, tumor location, and high MT levels are associated with higher rates of metastatic disease. Surgery is the only curative treatment. Treatment options for patients with metastatic disease are limited. PGL/PCCs have a strong genetic background, with at least one-third of all cases linked with germline mutations in 11 susceptibility genes. As genetic testing becomes more widely available, the diagnosis of PGL/PCCs will be made earlier due to routine screening of at-risk patients. Early detection of a familial PGL allows early detection of potentially malignant PGLs and early surgical treatment, reducing the complication rates of this operation.

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.

Management of medullary thyroid carcinoma and MEN2 syndromes in childhood

Medullary thyroid carcinoma (MTC) and the multiple endocrine neoplasia (MEN) type 2 syndromes are rare but important endocrine diseases that are increasingly managed by pediatric providers. MTC is generally associated with a favorable prognosis when diagnosed during childhood, where it frequently occurs secondary to activating mutations in the RET proto-oncogene and arises from pre-existing C-cell hyperplasia. MEN2A accounts for 90-95% of childhood MTC cases and is most commonly due to mutations in codon 634 of RET. MEN2B is associated with the most aggressive clinical presentation of MTC and is almost always due to the Met918Thr mutation of RET. Surgery is the primary treatment and only chance of cure, although the advent of targeted therapies seems to be improving progression-free survival in advanced cases. Since the discovery of the role of RET in MEN2A, considerable advances in the management of this syndrome have occurred, and most of the children with MEN2A who have undergone early thyroidectomy will now lead full, productive lives. Strong genotype-phenotype correlations have facilitated the development of guidelines for interventions. Contemporary approaches for deciding the appropriate age at which surgery should take place incorporate data from ultrasonography and calcitonin measurements in addition to the results of genotyping. To optimize care and to facilitate ongoing research, children with MTC and the MEN2 syndromes are optimally treated at tertiary centers with multidisciplinary expertise.

Improved plasma free metadrenaline analysis requires mixed mode cation exchange solid-phase extraction prior to liquid chromatography tandem mass spectrometry detection

Background

The investigation and effective management of phaeochromocytoma involves biochemical measurement of either conjugated total urine or plasma free metadrenalines. Current analytical methods include enzyme-linked immunosorbent assays, high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) or liquid chromatography tandem mass spectrometry (LCMS/MS). Since the first two methods are either extremely laborious, necessitate low sample run numbers, result in slow turnaround times or are subject to analytical interference, a robust, routine clinical method is not achievable. We established a novel sample preparation method to measure plasma free metadrenalines using LCMS/MS.

Methods

Three different solid-phase extraction (SPE) methods were compared: hydrophilic–lipophilic balance sorbent (HLB), weak cation exchange (WCX) and mixed mode cation exchange (MCX) and their ability to remove interfering compounds prior to LCMS/MS analysis. Maximum recovery of plasma free metadrenaline and plasma free normetadrenaline were achieved by positively charging compounds prior to SPE application.

Results

Compared with HLB and WCX cartridges, MCX extraction resulted in chromatography without co-eluting interference with superior assay precision and accuracy. Additionally, samples that could not be quantified because of interference using HPLC/ECD could be readily assayed using this new method.

Conclusions

The use of the MCX SPE method with LCMS/MS detection provides an improved assay to measure plasma free metadrenalines in comparison to many available alternative methods.