Carcinoid syndrome

Surgical aspects of small intestinal neuroendocrine tumors

Small intestinal neuroendocrine tumors (NETs) are a heterogeneous group of epithelial tumors with a predominant neuroendocrine differentiation. Although NETs are usually considered rare neoplasms, small intestinal NETs are the most common primary malignancy of the small bowel, with an increasing prevalence worldwide during the course of the past few decades. The indolent nature of these tumors often leads to a delayed diagnosis, resulting in over one-third of patients presenting with synchronous metastases. Primary tumor resection remains the only curative option for this type of tumor. In this review article, the various surgical aspects for the excision of small intestinal NETs are discussed.

Potassium in Solid Cancers

Electrolyte disorders are a frequent finding in cancer patients. In the majority of cases the etiologies of such disorders are common to all cancer types (i.e. diuretic-induced hyponatremia or hypokalemia). Sometimes, electrolyte disorders are caused by paraneoplastic syndromes or are due to cancer therapy. Potassium is one of the most important electrolytes of the human body since it is involved in the regulation of muscle contraction, maintenance of the integrity of the skeleton, blood pressure and nerve transmission as well as in the normal function of cells. Potassium homeostasis is strictly regulated since the gap between the recommended daily dietary intake (120 mEq/day) and the levels stored in the extracellular fluid (around 70 mEq) is huge. Alterations of potassium homeostasis are frequent in cancer patients as well alterations in potassium channels, the transmembrane proteins that mediate potassium fluxes within the cells. The present chapter is focused on the clinical significance of potassium homeostasis and potassium channels in patients with solid tumors.

Outcomes and periprocedural management of cardiac implantable electronic devices in patients with carcinoid heart disease

BACKGROUND

Carcinoid heart disease (CHD) is a rare complication of hormonally active neuroendocrine tumors that often requires surgical intervention. Data on cardiac implantable electronic device (CIED) implantation in patients with CHD are limited.

OBJECTIVE

The purpose of this study was to evaluate the experience of CIED implantation in patients with CHD.

METHODS

Patients with a diagnosis of CHD and a CIED procedure from January 1, 1995, through June 1, 2020, were identified using a Mayo Clinic proprietary data retrieval tool. Retrospective review was performed to extract relevant data, which included indications for implant, procedural details, complications, and mortality.

RESULTS

A total of 27 patients (55.6% male; mean age at device implant 65.6 ± 8.8 years) with cumulative follow-up of 75 patient-years (median 1.1 years; interquartile range 0.4-4.6 years) were included for analysis. The majority of implanted devices were dual-chamber permanent pacemakers (63%). Among all CHD patients who underwent any cardiac surgery, the incidence of CIED implantation was 12%. The most common indication for implantation was high-grade heart block (66.7%). Device implant complication rates were modest (14.8%). No patient suffered carcinoid crisis during implantation, and there was no periimplant mortality. Median time from implant to death was 2.5 years, with 1-year mortality of 15%.

CONCLUSION

CHD is a morbid condition, and surgical valve intervention carries associated risks, particularly a high requirement for postoperative pacing needs. Our data suggest that CIED implantation can be performed relatively safely. Clinicians must be aware of the relevant carcinoid physiology and take appropriate precautions to mitigate risks.

Confounders of severe asthma: diagnoses to consider when asthma symptoms persist despite optimal therapy

Asthma can often be challenging to diagnose especially when patients present with atypical symptoms. Therefore, it is important to have a broad differential diagnosis for asthma to ensure that other conditions are not missed. Clinicians must maintain a high index of suspicion for asthma mimickers, especially when patients fail to respond to conventional therapy. The purpose of this review is to briefly review some of the more common causes of asthma mimickers that clinicians should consider when the diagnosis of asthma is unclear.

Flushing Disorders Associated with Gastrointestinal Symptoms: Part 1, Neuroendocrine Tumors, Mast Cell Disorders and Hyperbasophila

Flushing is the subjective sensation of warmth accompanied by visible cutaneous erythema occurring throughout the body with a predilection for the face, neck, pinnae, and upper trunk where the skin is thinnest and cutaneous vessels are superficially located and in greatest numbers. Flushing can be present in either a wet or dry form depending upon whether neural-mediated mechanisms are involved. Activation of the sympathetic nervous system results in wet flushing, accompanied by diaphoresis, due to concomitant stimulation of eccrine sweat glands. Wet flushing is caused by certain medications, panic disorder and paroxysmal extreme pain disorder (PEPD). Vasodilator mediated flushing due to the formation and release of a variety of biogenic amines, neuropeptides and phospholipid mediators such as histamine, serotonin and prostaglandins, respectively, typically presents as dry flushing where sweating is characteristically absent. Flushing occurring with neuroendocrine tumors accompanied by gastrointestinal symptoms is generally of the dry flushing variant, which may be an important clinical clue to the differential diagnosis. A number of primary diseases of the gastrointestinal tract cause flushing, and conversely extra-intestinal conditions are associated with flushing and gastrointestinal symptoms. Gastrointestinal findings vary and include one or more of the following non-specific symptoms such as abdominal pain, nausea, vomiting, diarrhea or constipation. The purpose of this review is to provide a focused comprehensive discussion on the presentation, pathophysiology, diagnostic evaluation and management of those diseases that arise from the gastrointestinal tract or other site that may cause gastrointestinal symptoms secondarily accompanied by flushing. This review is divided into two parts given the scope of conditions that cause flushing and affect the gastrointestinal tract: Part 1 covers neuroendocrine tumors (carcinoid, pheochromocytomas, vasoactive intestinal polypeptide, medullary carcinoma of the thyroid), polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS), and conditions involving mast cells and basophils; while Part 2 covers dumping syndrome, mesenteric traction syndrome, rosacea, hyperthyroidism and thyroid storm, anaphylaxis, panic disorders, paroxysmal extreme pain disorder, and food, alcohol and medications.

Pharmacology of Octreotide: Clinical Implications for Anesthesiologists and Associated Risks

Many patients presenting with a history of foregut, midgut neuroendocrine tumors (NETs) or carcinoid syndrome can experience life-threatening carcinoid crises during anesthesia or surgery. Clinicians should understand the pharmacology of octreotide and appreciate the use of continuous infusions of high-dose octreotide, which can minimize intraoperative carcinoid crises. We administer a prophylactic 500-μg bolus of octreotide intravenously (IV) and begin a continuous infusion of 500 μg/h for all NET patients. Advantages include low cost and excellent safety profile. High-dose octreotide for midgut and foregut NETs requires an appreciation of the pathophysiology involved in the disease, pharmacology, drug-drug interactions, and side effects.

Endobronchial Carcinoid and Concurrent Carcinoid Syndrome in an Adolescent Female

Endobronchial carcinoid tumors are the most common intrabronchial tumors in children and adolescents. Common signs and symptoms include persistent cough and wheezing not responsive to bronchodilators, hemoptysis, and recurrent fever. Diagnosis is frequently made by imaging and direct visualization with flexible bronchoscopy; surgery remains the gold standard treatment, and lung-sparing resections should be performed whenever possible. Though carcinoid syndrome—characterized by flushing, palpitations, wheezing, shortness of breath, and diarrhea—has been found in association with adult bronchial carcinoid tumors, to our knowledge only one previous study has reported the presence of carcinoid syndrome in a pediatric patient with an endobronchial carcinoid. Here, we report a case of a 14-year-old girl with chronic cough found to have an endobronchial carcinoid tumor and signs and symptoms consistent with carcinoid syndrome.

Efficacy and Safety of Everolimus in Extrapancreatic Neuroendocrine Tumor: A Comprehensive Review of Literature

BACKGROUND

Everolimus, an oral mTOR (mammalian target of rapamycin) inhibitor, is currently approved for the treatment of progressive pancreatic neuroendocrine tumors (NETs). Although promising, only scattered data, often from nondedicated studies, are available for extrapancreatic NETs.

PATIENTS AND METHODS

A systematic review of the published data was performed concerning the use of everolimus in extrapancreatic NET, with the aim of summarizing the current knowledge on its efficacy and tolerability. Moreover, the usefulness of everolimus was evaluated according to the different sites of the primary.

RESULTS

The present study included 22 different publications, including 874 patients and 456 extrapancreatic NETs treated with everolimus. Nine different primary sites of extrapancreatic NETs were found. The median progression-free survival ranged from 12.0 to 29.9 months. The median time to progression was not reached in a phase II prospective study, and the interval to progression ranged from 12 to 36 months in 5 clinical cases. Objective responses were observed in 7 prospective studies, 2 retrospective studies, and 2 case reports. Stabilization of the disease was obtained in a high rate of patients, ranging from 67.4% to 100%. The toxicity of everolimus in extrapancreatic NETs is consistent with the known safety profile of the drug. Most adverse events were either grade 1 or 2 and easy manageable with a dose reduction or temporary interruption and only rarely requiring discontinuation.

CONCLUSION

Treatment with everolimus in patients with extrapancreatic NETs appears to be a promising strategy that is safe and well tolerated. The use of this emerging opportunity needs to be validated with clinical trials specifically designed on this topic.

IMPLICATIONS FOR PRACTICE

The present study reviewed all the available published data concerning the use of everolimus in 456 extrapancreatic neuroendocrine tumors (NETs) and summarized the current knowledge on the efficacy and safety of this drug, not yet approved except for pancreatic NETs. The progression-free survival rates and some objective responses seem promising and support the extension of the use of this drug. The site-by-site analysis seems to suggest that some subtypes of NETs, such as colorectal, could be more sensitive to everolimus than other primary NETs. No severe adverse events were usually reported and discontinuation was rarely required; thus, everolimus should be considered a valid therapeutic option for extrapancreatic NETs.

Evolution in the treatment of gastroenteropancreatic-neuroendocrine neoplasms, focus on systemic therapeutic options: a systematic review

ABSTRACT 

Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors. The present review discusses current therapeutic strategies for the treatment of gastro-entero-pancreatic NEN. Several systemic options are currently available, including medical systemic chemotherapy, biological drugs, somatostatin analogs and peptide receptor radionuclide therapy. The carcinoid syndrome can be adequately controlled with somatostatin analogs; chemotherapy has shown positive outcomes in poor prognosis patients, and peptide receptor radionuclide therapy is a promising treatment based on the use of radioisotopes for advanced disease expressing somatostatin receptors. Targeted therapies, such as multikinase inhibitors and monoclonal antibodies are also recommended or under evaluation for the treatment of advanced NENs, but some critical issues in clinical practice remain unresolved. Depending upon the development of the disease, a multimodal approach is recommended. The treatment strategy for metastatic patients should be planned by a multidisciplinary team in order to define the optimal sequence of treatments.

Therapeutic pulmonary artery stenting for metastatic bronchial carcinoid

We present a case of a middle-aged man with a 3-month history of progressive shortness of breath and peripheral oedema. Ten years prior to this, he had undergone a left pneumonectomy for metastatic bronchial carcinoid. Clinical examination revealed significant right heart failure, supported by transthoracic echocardiography. CT pulmonary angiogram revealed the cause to be marked progression of the bronchial carcinoid causing severe external compression of right pulmonary artery (RPA). In view of the distressing symptoms, a palliative endovascular intervention to the RPA was attempted to relieve obstruction, improve blood flow through the right lung and offload the right ventricle. This was performed under general anaesthesia involving interventional cardiology and radiology specialists together with a specialist anaesthetic team with extensive experience of managing carcinoid patients. The result was a marked improvement in symptoms and right heart function and the patient was discharged 2 days later.

Carcinoid syndrome and perioperative anesthetic considerations

Carcinoid tumors are uncommon, slow-growing neoplasms. These tumors are capable of secreting numerous bioactive substances, which results in significant potential challenges in the management of patients afflicted with carcinoid syndrome. Over the past two decades, both surgical and medical therapeutic options have broadened, resulting in improved outcomes. The pathophysiology, clinical signs and symptoms, diagnosis, treatment options, and perioperative management, including anesthetic considerations, of carcinoid syndrome are presented.

Primary carcinoid tumour of the liver in a young Filipino female

A 22-year-old female patient presented with rapid weight loss and an abdominal mass of 6 months duration. No other symptoms were noted. Liver function tests and α-fetoprotein were normal. Initial abdominal CT scan showed a large hepatic mass occupying both lobes of the liver, which was diagnosed as carcinoid tumour by liver biopsy. Workups to search for a primary lesion in the gastrointestinal tract and pancreas by oesophagogastroduodenoscopy, colonoscopy and holoabdominal triphasic CT scan with triple contrast failed to reveal the presence of a primary tumour. Subcentimetre pulmonary nodules, believed to be metastatic, were detected on chest CT scan. Bone scan showed no evident bone metastasis. Because of the non-resectability of the tumour, transarterial chemoembolisation was offered as an alternative to treatment, however, the patient opted for palliative care. She succumbed to respiratory failure 6 months after diagnosis.

Long-term survival with metastatic carcinoid tumors: a case report and review of the literature

Post hoc studies investigating patients with metastatic carcinoid tumors consistently have demonstrated outcomes that are not all too promising in terms of long-term survival, particularly for those with multiple metastases to the small bowel, mesentery, and liver. Here we present a patient with these clinical findings who, contrary to current expectations, has survived much longer than anticipated. This case is a sobering reminder for physicians not only to evaluate carefully and care for their patients but also to choose their words carefully in all communication with them.

Carcinoid tumors

Carcinoid tumors, which arise from the enterochromaffin cells of the gastrointestinal tract, encompass a diverse group of neoplasms. Once thought to be "carcinoma-like," these neoplasms exhibit a biologic behavior that varies from an indolent, benign course to an aggressive, rapidly progressive, and deadly disease. Today the term carcinoid is reserved for neuroendocrine tumors arising from the small bowel or neuroendocrine tumors that can cause carcinoid syndrome. This newer terminology has yet to be universally adopted, adding to the confusion in the literature. For the general surgeon there are several "carcinoid" tumors that he or she must be familiar with because many of these lesions are encountered during emergency laparotomies or incidentally discovered during investigation for vague abdominal pain. This review focuses on the gastrointestinal neuroendocrine tumors that general surgeons are likely to encounter during their career.

Improvements in small bowel carcinoid diagnosis and staging: 18F-DOPA PET, capsule endoscopy and double balloon enteroscopy

Carcinoid tumours are rare, slow growing tumours, originating from cells of the neuroendocrine system. Staging of the disease is of paramount importance to determine the optimal treatment strategy but is notoriously difficult. A case of a 45-year-old male who presented with abdominal pain and flushes is presented. An abdominal computerised tomography-scan was performed which showed a solitary liver lesion, consisting of neuroendocrine tumour cells. Further staging with (18)F-DOPA PET, capsule endoscopy and double balloon enteroscopy revealed the localisation of the primary tumours in the small bowel, and the patient subsequently underwent surgery. The recent introduction of (18)F-DOPA PET, capsule endoscopy and double balloon enteroscopy in the diagnosis and staging of carcinoid tumours has made significant contributions to the management of this disease.

Carcinoid tumors

Carcinoid tumors are rare, slow-growing neuroendocrine tumors arising from the enterochromaffin cells disseminated throughout the gastrointestinal and bronchopulmonary systems. Though they have been traditionally classified based on embryologic site of origin, morphologic pattern, and silver affinity, newer classification systems have been developed to emphasize the considerable clinical and histopathologic variability of carcinoid tumors found within each embryologic site of origin. These neoplasms pose a diagnostic challenge because they are often innocuous at the time of presentation, emphasizing the need for a multidisciplinary diagnostic approach using biochemical analysis, standard cross-sectional imaging, and newer advances in nuclear medicine. Similarly, treatment of both primary and disseminated carcinoid disease reflects the need for a multidisciplinary approach, with surgery remaining the only curative modality. The prognosis for patients with these tumors is generally favorable; however, it can be quite variable and is related to the location of the primary tumor, extent of metastatic disease at initial presentation, and time of diagnosis.