Discover the most talked about and latest scientific content & concepts.

Concept: Pheochromocytoma


Takotsubo cardiomyopathy is seen, though rarely, in anaphylaxis treated with epinephrine. Stress cardiomyopathy is most likely to occur in middle-aged women. The underlying etiology is believed to be related to catecholamine release in periods of intense stress. Catecholamines administered exogenously, and those secreted by neuroendocrine tumors (e.g., pheochromocytoma) or during anaphylaxis have been reported to cause apical ballooning syndrome, or takotsubo syndrome. However, reverse takotsubo stress cardiomyopathy is rarely seen or reported in anaphylaxis treated with epinephrine.

Concepts: Neuroendocrine tumor, Norepinephrine, Cardiovascular diseases, Cardiomyopathy, Pheochromocytoma, Epinephrine, Takotsubo cardiomyopathy, Catecholamine


Multiple endocrine neoplasia type 2 (MEN2) refers to the autosomal dominant neuroendocrine tumour syndromes, MEN type 2A (MEN2A) and MEN type 2B (MEN2B). They are typified by the development of medullary thyroid carcinoma (MTC), phaeochromocytoma and parathyroid hyperplasia in MEN2A, and MTC, phaeochromocytomas, ganglioneuromatosis and skeletal abnormalities in MEN2B. The aggressiveness of MTC is variable according to genotype, and although it is still the major cause of mortality in both conditions, prognosis has improved dramatically in those diagnosed and treated at a young age thanks to predictive genetic testing. Nevertheless, metastatic MTC, ganglioneuromatosis and a variety of other negative clinical and psychosocial impacts on quality of life and/or prognosis in MEN2 persist. In the absence at time of writing of any large scale research into quality of life specifically in MEN2, this review includes data from patient surveys and anonymised patient anecdotes from the records of the Association for Multiple Endocrine Neoplasia Disorders (AMEND), for whom the authors work. We recommend that these patients are cared for only in centres of expertise able to provide expert diagnosis, treatment and continuity of care, including psychological and transition support. Only in this way can the clinical advances of the last two and half decades be built upon further to ensure that the care of these complex, lifelong patients can be considered truly holistic.

Concepts: RET proto-oncogene, Endocrinology, Thyroid, Multiple endocrine neoplasia type 2, Oncology, Cancer, Pheochromocytoma, Multiple endocrine neoplasia


Twenty-five years ago, RET was identified as the primary driver of multiple endocrine neoplasia type 2 (MEN2) syndrome. MEN2 is characterized by several transformation events including pheochromocytoma, parathyroid adenoma and, especially penetrant, medullary thyroid carcinoma (MTC). Overall, MTC is a rare but aggressive type of thyroid cancer for which no effective treatment currently exists. Surgery, radiation, radioisotope treatment and chemotherapeutics have all shown limited success, and none of these approaches have proven durable in advanced disease. Non-mammalian models that incorporate the oncogenic RET isoforms associated with MEN2 and other RET-associated diseases have been useful in delineating mechanisms underlying disease progression. These models have also identified novel targeted therapies as single agents and as combinations. These studies highlight the importance of modeling disease in the context of the whole animal, accounting for the complex interplay between tumor and normal cells in controlling disease progression as well as response to therapy. With convenient access to whole genome sequencing data from expanded thyroid cancer patient cohorts, non-mammalian models will become more complex, sophisticated and continue to complement future mammalian studies. In this review, we explore the contributions of non-mammalian models to our understanding of thyroid cancer including MTC, with a focus on Danio rerio and Drosophila melanogaster (fish and fly) models.

Concepts: Medicine, Pheochromocytoma, RET proto-oncogene, Types of cancer, Medullary thyroid cancer, Cancer, Multiple endocrine neoplasia, Oncology


Multiple endocrine neoplasia type 2A (MEN2A) is a hereditary syndrome. Here, two different RET proto-oncogen mutation were identified from family members of two MEN2A pedigrees by genetic screening. One RET mutations were found at codons 1893 and 1895 in exon 11 (1893-1895delCGA) from pedigree 1, which is a novel mutation, the other occurs at codon 634 (Cys634Arg) in exon 11 from pedigree 2. However, the clinical characteristics were similar in the patients of the two pedigrees. All the patients were in middle-age at onset. Most of them were firstly diagnosed with bilateral adrenal pheochromocytoma with different degrees of thyroid abnormalities (elevated serum calcitonin with or without thyroid mass, or had been diagnosed with medullary thyroid carcinoma). Some family members were with elevated serum parathyroid hormone but with no other evidences for hyperparathyroidism.

Concepts: Pheochromocytoma, Medullary thyroid cancer, Parathyroid gland, Cancer, DNA, Parathyroid hormone, Calcitonin, Multiple endocrine neoplasia


Multiple endocrine neoplasia type 2 (MEN2) affects patients with RET proto-oncogene mutations. This cohort study refers to patients who were diagnosed with familial medullary thyroid carcinoma (MTC) and underwent RET genetic testing in Cyprus between years 2002 and 2017.

Concepts: Endocrine system, Pheochromocytoma, Evolution, Cancer, Multiple endocrine neoplasia type 2, RET proto-oncogene, Medullary thyroid cancer, Multiple endocrine neoplasia


Pheochromocytomas (PCCs) are tumors that are derived from the chromaffin cells of the adrenal medulla. Extra-adrenal PCCs called paragangliomas (PGLs) are derived from the sympathetic and parasympathetic chain ganglia. PCCs secrete catecholamines which cause hypertension and have adverse cardiovascular consequences as a result of catecholamine excess. PGLs may or may not produce catecholamines depending on their genetic type and anatomical location. The most worrisome aspect of these tumors is their ability to become aggressive and metastasize, for which there are no known cures.

Concepts: Sympathetic nervous system, Adrenal gland, Fight-or-flight response, Catecholamine, Chromaffin cell, Pheochromocytoma, Epinephrine, Adrenal medulla


Germline RET K666N mutation has been described as a pathogenic mutation with low disease penetrance for medullary thyroid cancer (MTC) without other features of MEN2A. We describe a patient with homozygous RET K666N mutation with MTC and bilateral pheochromocytoma (PHEO).

Concepts: Pheochromocytoma, Multiple endocrine neoplasia type 2, Medullary thyroid cancer


Catecholamine crises associated with pheochromocytoma may cause life-threatening cardiovascular conditions. We report the case of a 75-year-old male who developed a hypertensive crisis during induction of general anesthesia for elective resection of a cervical neuroma due to an undiagnosed pheochromocytoma. Hemodynamic instability occurred immediately after the injection of fentanyl, propofol and rocuronium, prior to laryngoscopy and in the absence of any manipulation of the abdomen. In this case report, we present the management of this incident and discuss the underlying pathophysiology triggering a catecholamine crisis.

Concepts: Logic, Epinephrine, Pheochromocytoma, Hypertension


The revised guidelines for the management of medullary thyroid carcinoma recommend that genetic counseling regarding reproductive options, including preimplantation genetic diagnosis (PGD), be considered for all RET mutation carriers of reproductive age to avoid the transmission of multiple endocrine neoplasia type 2 (MEN2). However, the high complexity and cost of PGD have hindered its widespread use. Thus, it is necessary to establish a simple and relatively inexpensive method to facilitate the PGD of MEN2.

Concepts: Endocrine system, Cancer, Pheochromocytoma, Multiple endocrine neoplasia type 2, Medullary thyroid cancer, RET proto-oncogene, Preimplantation genetic diagnosis, Multiple endocrine neoplasia


Adrenal tumors are increasingly found incidentally during imaging examinations. It is important to distinguish pheochromocytomas from other adrenal tumors because of the risk of hypertensive crisis. Although catecholamines and their metabolites are generally used to diagnose pheochromocytoma, false-positive test results are common. An effective screening method to distinguish pheochromocytoma from adrenal incidentalomas is needed. We analyzed 297 consecutive patients with adrenal incidentalomas. Our findings included 162 non-functioning tumors, 47 aldosterone-producing adenomas, 26 metastases, 22 cases of subclinical Cushing’s syndrome, 21 pheochromocytomas, 12 cases of Cushing’s syndrome, and 7 adrenocortical cancers. We checked quantitative parameters such as age, blood, and urine catecholamines and their metabolites, neuron-specific enolase, size and computed tomography (CT) attenuation values. Among catecholamine-related parameters, the sum of urine metanephrine and normetanephrine (urineMNM) levels produced the highest area under the receiver operating characteristic curve regarding discrimination of pheochromocytoma from other lesions. Size and CT attenuation values also differed significantly. However, size was correlated with catecholamine levels. CT attenuation was not correlated with other factors. The optimal thresholds were 19 Hounsfield units (HU) for CT attenuation (sensitivity, 100%; specificity, 60%) and 0.43 mg/24 h for urineMNM (sensitivity, 89%; specificity, 96%). No pheochromocytomas were evident when CT attenuation values were under 19 HU. Even in adrenal tumors with CT attenuation values ≥ 19 HU, when urineMNM was < 0.43 mg/24 h, the frequency of pheochromocytoma was only 4.3%, when urineMNM was ≥ 0.43 mg/24 h, the frequency of pheochromocytoma was 93% and when urineMNM was > 0.77 mg/24 h the frequency of pheochromocytoma was 100%. CT attenuation value and urineMNM represented the most useful combination for diagnosis of pheochromocytoma.

Concepts: Cancer, Catecholamine, Epinephrine, Type I and type II errors, Adrenal medulla, Cortisol, Hypertension, Pheochromocytoma