Publications by authors named "Hjlm Timmers"

Objective: Head-neck paragangliomas (HNPGLs) are rare tumors with approximately half arising due to germline pathogenic variants (PVs) in succinate dehydrogenase genes (SDHx). Patients with HNPGL have heterogeneous propensity to recur and metastasize. Thus, we aim to assess prevalence and predictors of recurrent (RD) and/or metastatic disease in patients with and without SDHx-related HNPGLs.

View Article and Find Full Text PDF

Objective: Hereditary pheochromocytoma (hPCC) commonly develops bilaterally, causing adrenal insufficiency when standard treatment, radical adrenalectomy (RA), is performed. Partial adrenalectomy (PA) aims to preserve adrenal function, but with higher recurrence rates. This study compares outcomes of PA versus RA in hPCC.

View Article and Find Full Text PDF

Background: Carriers of germline pathogenic variants (PVs) in succinate dehydrogenase genes () are at risk of developing tumors, including paragangliomas, gastrointestinal stromal tumors, and renal cell carcinomas. Early tumor detection is paramount for improved clinical outcome. Blood-based biomarkers could aid in identifying individuals with PVs early and provide functional evidence in patients with variants of unknown significance.

View Article and Find Full Text PDF

Phaeochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours arising from chromaffin cells. Pathogenic variants in the gene are associated with malignancy and poor prognosis. When metastases arise, limited treatment options are available.

View Article and Find Full Text PDF

Entrustable Professional Activities (EPAs) are an important tool to support individualisation of medical training in a competency-based setting and are increasingly implemented in the clinical speciality training for endocrinologist. This study aims to assess interrater agreement and factors that potentially impact EPA scores. Five known factors that affect entrustment decisions in health profesions training (capability, integrity, reliability, humility, agency) were used in this study.

View Article and Find Full Text PDF

Background: Posterior retroperitoneoscopic adrenalectomy has several advantages over transabdominal laparoscopic adrenalectomy regarding operating time, blood loss, postoperative pain, and recovery. However, postoperatively several patients report chronic pain or hypoesthesia. We hypothesized that these symptoms may be the result of damage to the subcostal nerve, because it passes the surgical area.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the factors leading to missed presurgical diagnoses of paragangliomas of the urinary bladder (UBPGLs), rare neuroendocrine tumors that pose diagnostic challenges.
  • Out of 124 patients analyzed from multiple regions, only about 47.6% were diagnosed before surgery, with those diagnosed earlier being younger and having larger tumors.
  • Key symptoms like micturition spells, hypertension, and sweating were found to significantly increase the likelihood of early biochemical testing, suggesting they could help establish timely diagnoses.
View Article and Find Full Text PDF

Most women with Turner syndrome have premature ovarian insufficiency from childhood. The chance of a spontaneous pregnancy is higher in women with a Turner mosaicism and in women who have had a spontaneous menarche. This chance is estimated at 5-8%.

View Article and Find Full Text PDF

Pheochromocytomas/paragangliomas are unique in their highly variable molecular landscape driven by genetic alterations, either germline or somatic. These mutations translate into different clusters with distinct tumor locations, biochemical/metabolomic features, tumor cell characteristics (eg, receptors, transporters), and disease course. Such tumor heterogeneity calls for different imaging strategies in order to provide proper diagnosis and follow-up.

View Article and Find Full Text PDF

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time.

View Article and Find Full Text PDF
Article Synopsis
  • The study looked at different treatments for patients with metastatic pheochromocytomas/paragangliomas (mPPGLs) and how well they worked.
  • It included 74 patients from 6 specialized centers and checked their responses to several therapies.
  • The results showed that most treatments, including some for patients with a specific genetic mutation (SDHB), were effective at controlling the disease and preventing it from getting worse.
View Article and Find Full Text PDF

The biochemical phenotype of paragangliomas (PGLs) is highly dependent on the underlying genetic background and tumor location. PGLs at extra-adrenal locations usually do not express phenylethanolamine N-methyltransferase (PNMT), the enzyme required for epinephrine production, which was explained by the absence of glucocorticoids. PGLs with pathogenic variants (PVs) in Harvey rat sarcoma viral oncogene homolog (HRAS) can occur in or outside of the adrenal, but always synthesize epinephrine independently of the localization.

View Article and Find Full Text PDF

Background: Pheochromocytomas and paragangliomas have up to a 20% rate of metastatic disease that cannot be reliably predicted. This study prospectively assessed whether the dopamine metabolite, methoxytyramine, might predict metastatic disease, whether predictions might be improved using machine learning models that incorporate other features, and how machine learning-based predictions compare with predictions made by specialists in the field.

Methods: In this machine learning modelling study, we used cross-sectional cohort data from the PMT trial, based in Germany, Poland, and the Netherlands, to prospectively examine the utility of methoxytyramine to predict metastatic disease in 267 patients with pheochromocytoma or paraganglioma and positive biochemical test results at initial screening.

View Article and Find Full Text PDF

Patients with germline SDHD pathogenic variants (encoding succinate dehydrogenase subunit D; ie, paraganglioma 1 syndrome) are predominantly affected by head and neck paragangliomas, which, in almost 20% of patients, might coexist with paragangliomas arising from other locations (eg, adrenal medulla, para-aortic, cardiac or thoracic, and pelvic). Given the higher risk of tumour multifocality and bilaterality for phaeochromocytomas and paragangliomas (PPGLs) because of SDHD pathogenic variants than for their sporadic and other genotypic counterparts, the management of patients with SDHD PPGLs is clinically complex in terms of imaging, treatment, and management options. Furthermore, locally aggressive disease can be discovered at a young age or late in the disease course, which presents challenges in balancing surgical intervention with various medical and radiotherapeutic approaches.

View Article and Find Full Text PDF
Article Synopsis
  • Pheochromocytomas and paragangliomas (PPGLs) with mutations in the SDHB gene have a high risk of metastasis, and SSTR2-dependent imaging is the most effective way to detect these tumors, indicating SSTR2 as a key therapeutic biomarker.
  • A study analyzed data from 202 PPGL patients across multiple centers to assess the relationship between SSTR2 and SDHB expression, mutation status, and clinical behavior.
  • Results showed that half of the patients had SSTR2 positivity, which correlated with SDHB mutations and metastatic disease, highlighting the effectiveness of SSTR-based therapies in controlling the disease in metastatic cases.
View Article and Find Full Text PDF

Context: Long-term follow-up has been recommended for patients with pheochromocytoma or paraganglioma (PPGL) due to potential for recurrent disease. However, the need to follow patients with sporadic PPGL has recently become controversial.

Objective: To investigate the prevalence of recurrence among patients with sporadic compared with hereditary PPGL and to identify predictors of recurrence for sporadic disease.

View Article and Find Full Text PDF

Pheochromocytomas (PC) and paragangliomas (PG) are rare neuroendocrine tumors with varied genetic makeup and are associated with high cardiovascular morbidity and a variable risk of malignancy. The source of the transcriptional heterogeneity of the disease and the underlying biological processes that determine the outcome of PCPG remain largely unclear. We focused on PCPG tumors with germline SDHB and RET mutations, which represent distinct prognostic groups with worse or better prognoses, respectively.

View Article and Find Full Text PDF

Objectives: Based on germline and somatic mutation profiles, pheochromocytomas and paragangliomas (PPGLs) can be classified into different clusters. We investigated the use of [F]FDG-PET/CT radiomics, SUV and biochemical profile for the identification of the genetic clusters of PPGLs.

Methods: In this single-centre cohort, 40 PPGLs (13 cluster 1, 18 cluster 2, 9 sporadic) were delineated using a 41% adaptive threshold of SUV ([F]FDG-PET) and manually (low-dose CT; ldCT).

View Article and Find Full Text PDF

Despite considerable morbidity and mortality, numerous cases of endocrine hypertension (EHT) forms, including primary aldosteronism (PA), pheochromocytoma and functional paraganglioma (PPGL), and Cushing's syndrome (CS), remain undetected. We aimed to establish signatures for the different forms of EHT, investigate potentially confounding effects and establish unbiased disease biomarkers. Plasma samples were obtained from 13 biobanks across seven countries and analyzed using untargeted NMR metabolomics.

View Article and Find Full Text PDF

Context: Sampling of blood in the supine position for diagnosis of pheochromocytoma and paraganglioma (PPGL) results in lower rates of false positives for plasma normetanephrine than seated sampling. It is unclear how inpatient vs outpatient testing and other preanalytical factors impact false positives.

Objective: We aimed to identify preanalytical precautions to minimize false-positive results for plasma metanephrines.

View Article and Find Full Text PDF
Article Synopsis
  • Minimally invasive adrenalectomy is commonly performed for small adrenal tumors, but this study focuses on the prevalence of chronic postsurgical pain, which hasn't been extensively researched before.
  • A total of 602 patients underwent the surgery between 2007 and 2019, with 14.9% experiencing chronic pain afterward, and 33% of those with pain also reported localized hypoesthesia (reduced sensation).
  • Young age emerged as a notable risk factor for chronic pain, and patients experiencing this pain reported a significantly lower quality of life compared to those without pain.*
View Article and Find Full Text PDF

Background: Clinical pathways are care plans established to describe essential steps in the care of patients with a specific clinical problem. They translate (inter)national guidelines into local applicable protocols and clinical practice. The purpose of this article is to establish a multidisciplinary integrated care pathway for specialists and allied health care professionals in caring for individuals with von Hippel-Lindau (VHL) disease.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated disease-specific survival (DSS) in patients with pheochromocytomas and paragangliomas (PPGLs) and head/neck paragangliomas (HNPGLs), focusing on factors influencing prognosis and outcomes.
  • Older age and the presence of metastases were major predictors of shorter DSS, alongside extra-adrenal tumor locations and elevated plasma levels of methoxytyramine and normetanephrine.
  • Interestingly, patients with metastatic HNPGLs had a longer DSS than those with metastatic PPGLs, with plasma methoxytyramine emerging as a key independent predictor for both groups.
View Article and Find Full Text PDF
Article Synopsis
  • Presurgical treatment for patients with pheochromocytoma or sympathetic paraganglioma often involves α-adrenergic receptor blockers to manage blood pressure, but individual responses to this treatment can vary significantly.
  • Researchers examined 31 genetic variations (SNPs) in specific α-adrenergic receptor genes among 116 participants, looking for links between genetics and treatment response.
  • They found that certain SNPs, particularly rs10515807 in the ADRA1B gene and specific SNPs in the ADRA2A gene, were associated with the need for higher doses of medication and increased side effects, indicating genetic factors may influence treatment effectiveness.
View Article and Find Full Text PDF

Background: Moderately elevated plasma normetanephrine (NMN) levels are frequent among patients with suspected pheochromocytoma and paraganglioma (PPGL). Clonidine suppression testing (CST) is recommended to distinguish patients with from those without PPGL. We aimed at evaluating the diagnostic outcome of CST in patients with moderate NMN elevations.

View Article and Find Full Text PDF