Perioperative Management of Pheochromocytomas and Sympathetic Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors arising from chromaffin cells of the adrenal medulla or extra-adrenal paraganglia, respectively. PPGLs have the highest degree of heritability among endocrine tumors. Currently, ~40% of PPGL individuals have a genetic germline and there exist at least 12 different genetic syndromes related to these tumors. Metastatic PPGLs are defined by the presence of distant metastases at sites where chromaffin cells are physiologically absent. Approximately 10% of pheochromocytomas and ~40% of sympathetic paragangliomas are linked to metastases explaining why complete surgical resection is the first-choice treatment for all PPGL patients. The surgical approach is a high-risk procedure requiring perioperative management by a specialized multidisciplinary team in centers with broad expertise. In this review, we summarize and discuss the most relevant aspects of perioperative management in patients with pheochromocytomas and sympathetic paragangliomas.

Intractable Seizures and Limbic Encephalitis, Unaccounted Complications of Type 1 Diabetes Autoimmunity

Glutamic acid decarboxylase 65kD autoantibody (GAD65Ab) is frequently detected in patients with refractory epilepsy and stiff person syndrome (SPS). In contrast to T1D, the pathological role of GAD65Ab in neurological disorders is still debatable. As a result, the implementation of possible immunotherapy is usually delayed. This report presents two cases of GAD65Ab associated brain autoimmunity and their different management. We present clinical data and discuss management based on available evidence in the reviewed literature. Both cases presented with acute on chronic neurological symptoms and were GAD65Ab positive. Case 1, a 30-year-old man with a history of early-onset T1D at 14 months, followed by cryptogenic temporal epilepsy at 11 years of age, presented with intractable seizures. Case 2, a 48-year-old woman, presented with a history of recurrent severe headaches, cognitive impairment, decreased memory, and behavioral symptoms. GAD65Ab was detected in both patients’ sera. CSF GAD65Ab was only checked and positive in case 1. Case 2 was diagnosed with limbic encephalitis, treated with immunotherapy, and showed a remarkable clinical improvement. Case 1 with refractory epilepsy failed multiple AEDs and Responsive-Stimulator System (RNS) treatments. He was finally diagnosed with autoimmune epilepsy. The delay in diagnosis resulted in a lost opportunity for early immunotherapy. In conclusion, autoantibody screening and early initiation of immunotherapy should be considered to manage GAD65Ab associated neurological disorders.

MEN1 Surveillance Guidelines: Time to (re)Think?

Clinical Practice Guidelines for patients with Multiple Endocrine Neoplasia type 1 (MEN1) recommend a variety of surveillance options. Given progress over the past decade in this area, it is timely to evaluate their ongoing utility. MEN1 is characterized by the development of synchronous or asynchronous tumors affecting a multitude of endocrine and non-endocrine tissues, resulting in premature morbidity and mortality, such that the rationale for undertaking surveillance screening in at-risk individuals appears robust. Current guidelines recommend an intensive regimen of clinical, biochemical and radiological surveillance commencing in early childhood for those with a clinical or genetic diagnosis of MEN1, with the aim of early tumor detection and treatment. Although it is tempting to assume that such screening results in patient benefits and improved outcomes, the lack of a strong evidence base for several aspects of MEN1 care, and the potential for iatrogenic harms related to screening tests or interventions of unproven benefit, make such assumptions potentially unsound. Furthermore, the psychological, as well as economic burdens of intensive screening remain largely unstudied. Although screening undoubtedly constitutes an important component of MEN1 patient care, this perspective aims to highlight some of the current uncertainties and challenges related to existing MEN1 guidelines with a particular focus on the role of screening for pre-symptomatic tumors. Looking forward, a screening approach that acknowledges these limitations and uncertainties and places the patient at the heart of the decision-making process, is advocated.

Gonadotropin Suppression for 7 Years after a Single Histrelin Implant for Precocious Puberty

Gonadotropin releasing hormone analogs (GnRHas) are an effective treatment to address the compromise in height potential seen in patients with central precocious puberty. There is no evidence in the literature of a single GnRHa used for longer than 2 years before being removed or replaced. We describe a patient who was on continuous gonadotropin suppression for 7 years and despite this, achieved a height potential within one standard deviation of mid-parental height. A boy aged 10 years and 3 months presented to endocrine clinic with signs of precocious puberty and advanced bone age. Initial labs showed random LH 9.4 mIU/mL, FSH 16.3 mIU/mL, DHEAS 127 mcg/dl, and testosterone 628 ng/dL. He was initially started on Lupron injections before transitioning to a Histrelin implant. Follow-up laboratory results 5 months post-suppression showed pre-pubertal random LH 0.2 mIU/mL, FSH 0.1 mIU/mL, and testosterone 5 ng/dL. The patient was lost to follow-up and returned 5 years later presenting with gynecomastia and delayed bone age. He had continuous gonadotropin suppression with random LH 0.10 mIU/mL, FSH 0.16 mIU/mL, and testosterone 8 ng/dL. The Histrelin implant was removed and 4 months after removal labs showed random pubertal hormone levels with LH 5.6 mIU/mL, FSH 4.3 mIU/mL, and testosterone 506 ng/dl. The patient’s mid-parental height was 175.3 cm and the patient’s near final height was 170.6 cm which is within one standard deviation of his genetic potential. Further studies are needed to explore continuous gonadotropin hormone suppression with a single Histrelin implant beyond 2 years.

Pathophysiology and Clinical Features of Neuropsychiatric Manifestations of Thyroid Disease

Thyroid hormones (TH) have a cardinal role in the development of the central nervous system during embryogenesis and early infancy. However, the TH responsive genes in the developing brain cease to respond to TH in adulthood. Nevertheless, thyroid dysfunction in adults is commonly associated with a host of cognitive and psychiatric problems. Cognitive decline, dysphoria and depression are common manifestations of overt hypothyroidism while hyperthyroidism can cause agitation, acute psychosis and apathy especially in older people. Whereas levothyroxine treatment can reverse dementia in the setting of hypothyroidism, the effect of levothyroxine on depressive symptoms in subjects with subclinical hypothyroidism is controversial. The use of supraphysiologic doses of TH to treat depression refractory to antidepressant remains a viable therapeutic tool with the caveat that excessive doses of thyroid hormone to treat depression may have potentially damaging effects on other organ systems. The present communication describes the pathophysiology of neuropsychiatric manifestations of thyroid disease including changes in neurotransmission, alterations in neuronal or glial cell gene expression, blood-brain barrier dysfunction, increased risk of cerebrovascular disease and occasionally cerebral inflammatory disease in the context of autoimmune thyroid disease. Elucidating the molecular mechanisms of TH effect on cerebral tissue will help identify novel therapeutic targets for managing people with neuropsychiatric disorders.

Hydrocortisone Suspension Provides Similar Growth Outcomes as Hydrocortisone Tablets in Young Children with CAH

Background Young children with CAH require small doses (0.1-1.25 mg) of hydrocortisone (HC) to control excess androgen production and avoid the negative effects of overtreatment. The smallest commercially available HC formulation, before the recent FDA approval of HC granules, was a scored 5 mg tablet. The options to achieve small doses were limited to using a pharmacy-compounded suspension, which the CAH Clinical Practice Guidelines recommended against, or splitting tablets into quarters or eighths, or dissolving tablets into water. Methods Cross sectional chart review of 130 children with classic CAH treated with tablets versus a pharmacy-compounded alcohol-free hydrocortisone suspension to compare growth, weight, skeletal maturation, total daily HC dose and exposure over the first four years of life. Results No significant differences were found in height, weight, or BMI z-scores at 4 years, and in predicted adult height, before or after adjusting for age at diagnosis and sex. Bone age z-scores averaged 2.8 SDs lower for patients on HC suspension compared to HC tablets (p<0.001) after adjusting for age at diagnosis and sex. The suspension group received 30.4% lower (p>0.001) average cumulative HC doses by their 4th birthday. Conclusions Our data indicates that treatment with alcohol-free HC suspension decreased androgen exposure as shown by lower bone age z-scores, allowed lower average and cumulative daily HC dose compared to HC tablets, and generated no significant differences in SDS in growth parameters in children with CAH at 4 years of age. Longitudinal studies of treating with smaller HC doses during childhood are needed.

The regulation of phoenixin: A fascinating multidimensional peptide

The phoenixin (PNX) peptide is linked to the control of reproduction, food intake, stress and inflammation. However, little is known about what regulates its gene and protein expression, information that is critical to understand the physiological role of PNX. In this review, we summarize what is known about the transcriptional control of Pnx and its receptor Gpr173. A main function of PNX is as a positive regulator of the hypothalamic-pituitary-gonadal axis, but there is a lack of research on its control by reproductive hormones and peptides. PNX is also associated with food intake and its expression is linked to feeding status, fatty acids, and glucose. It is influenced by environmental and hormonal-induced stress. The regulation of Pnx in most contexts remains an enigma, in part due to conflicting and negative results. An extensive analysis of the response of the Pnx gene to factors related to reproduction, metabolism, stress and inflammation is required. Analysis of the Pnx promoter and epigenetic regulation must be considered to understand how this level of control contributes to its pleiotropic effects. PNX is now linked to a broad range of functions, but more research on its gene regulation is required to understand its place in overall physiology and therapeutic potential.

Is there a role for biomarkers in surveillance of pancreatic neuroendocrine neoplasms in Von Hippel-Lindau’s disease?

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multi-organ neoplasms. Among the manifestations of VHL are pancreatic neuroendocrine neoplasms (panNENs). In order to detect these lesions in a timely manner, patients are enrolled in a surveillance program, in accordance with the several existing VHL guidelines. However, these guidelines remain unclear about the role of biomarkers in diagnosing panNENs, despite the benefits a biomarker may offer regarding early detection of new lesions, thereby possibly limiting radiation exposure, and improving quality of life. The aim is to determine which biomarkers might be available in VHL patients and to assess what their clinical relevance in diagnosing panNENs in VHL patients is. We searched the databases of Pubmed/Medline, Embase and Web of Science to identify relevant articles. Seven studies assessing the diagnostic or prognostic value of biomarkers were included. The results from these studies were conflicting. Since no evident association between VHL-related panNENs and biomarkers was established in studies with larger study populations, currently biomarkers do not play a significant role in early detection or follow-up for panNENs in VHL patients. The absence of evidence underscores the need for specific research to address this unmet need.

Temozolomide non-responsiveness in aggressive prolactinomas and carcinomas: management and outcomes

Purpose Temozolomide is endorsed as the treatment of choice in aggressive or malignant pituitary adenomas. Herein we describe a case of an aggressive prolactinoma which was resistant to temozolomide and performed a literature review of similar non-responsive aggressive prolactinomas. Methods A 40-year-old female presented with a giant prolactinoma which required cabergoline, transsphenoidal surgery and radiotherapy to achieve near-normal prolactin and apparently no residual tumour. A year later, she presented with multiple cranial nerve involvement due to recurrent tumour extending to the infratemporal fossa. She underwent transfrontal surgery, second radiotherapy and was started on temozolomide. Despite 8 cycles of temozolomide (200mg/m 2, 5/28 day cycle), she had progressive disease and ultimately succumbed to the disease. Pubmed/MEDLINE, Google scholar and prior review articles were searched for manuscripts with aggressive prolactinomas who had been treated with temozolomide. Data on demography, duration of therapy and management outcomes were analysed in those with progressive disease. Literature review We identified 94 cases of aggressive/malignant prolactinomas in the literature who had received temozolomide. Progressive disease despite temozolomide was present in 36 cases (38%). There was a male preponderance (65%) and 40% had aggressive prolactinomas while the rest had carcinomas. Patients received a median of 8 cycles (IQR 3.5-11.5) of temozolomide. MGMT immunostaining was negative in 35%. Overall mortality at the time of publication was 40%, at a duration varying from 2 to 20 years from diagnosis. Conclusion Temozolomide resistance in aggressive/malignant prolactinomas is challenging. Progressive disease on optimal temozolomide treatment entails the use of newer agents.