Multi-institutional assessment of the prevalence of neuroendocrine tumors in children undergoing laparoscopic appendectomy for acute appendicitis in the United States

As non-operative management of acute appendicitis in children has become more common, missed incidental appendiceal pathology can be an unintended consequence. We assessed the prevalence of neuroendocrine tumors in appendectomy specimens from eight US children's hospitals from 2012 to 2021. The prevalence of neuroendocrine tumors (NET) was found to be 1:271, with a median age of 14 years and 62% female. Most tumors were small (median 6 mm; interquartile range [IQR]: 3-10), and no recurrence was noted during the follow-up period (median 22.5 months; IQR: 3-53). The possibility of delayed diagnosis of these tumors should be part of the discussion for non-operative management of pediatric acute appendicitis.

Resection Versus Observation for Small (≤2 cm) Pancreatic Neuroendocrine Tumors

BACKGROUND

We hypothesized that those patients with pancreatic neuroendocrine tumors (pNETs) ≤2 cm managed nonoperatively would have comparable disease progression to individuals undergoing an operation.

METHODS

Patients diagnosed with nonfunctional pNETs ≤ 2 cm who were evaluated at a single comprehensive cancer center from 2010 to 2017 were selected from a cancer registry database. Clinicopathologic variables were obtained via retrospective chart review. Primary outcomes were overall and disease specific survival. Variables were compared between the 2 groups using chi-square and independent t-test.

RESULTS

Fifty-two individuals had tumors ≤2 cm, of whom 75% had an operation, while 25% were observed. Each treatment arm had similar distributions of gender, race, and tumor location. The most common operation was distal pancreatectomy (n = 29) followed by pancreatoduodenectomy (n = 6). Nine patients had grade III postoperative complications and 4 had grade IV under Clavien-Dindo classification. The observation group was noted to have a mean disease progression interval of 80.9 months, while those who underwent an operation had a mean disease progression interval of 94.6 months (P = .246).

CONCLUSIONS

Overall disease progression in patients with pNETs ≤ 2 cm without evidence of metastasis at the time of presentation is not different between those who underwent operation compared to those observed.

Pheochromocytoma: a changing perspective and current concepts

This article aims to review current concepts in diagnosing and managing pheochromocytoma and paraganglioma (PPGL). Personalized genetic testing is vital, as 40-60% of tumors are linked to a known mutation. Tumor DNA should be sampled first. Next-generation sequencing is the best and most cost-effective choice and also helps with the expansion of current knowledge. Recent advancements have also led to the increased incorporation of regulatory RNA, metabolome markers, and the NETest in PPGL workup. PPGL presentation is highly volatile and nonspecific due to its multifactorial etiology. Symptoms mainly derive from catecholamine (CMN) excess or mass effect, primarily affecting the cardiovascular system. However, paroxysmal nature, hypertension, and the classic triad are no longer perceived as telltale signs. Identifying high-risk subjects and diagnosing patients at the correct time by using appropriate personalized methods are essential. Free plasma/urine catecholamine metabolites must be first-line examinations using liquid chromatography with tandem mass spectrometry as the gold standard analytical method. Reference intervals should be personalized according to demographics and comorbidity. The same applies to result interpretation. Threefold increase from the upper limit is highly suggestive of PPGL. Computed tomography (CT) is preferred for pheochromocytoma due to better cost-effectiveness and spatial resolution. Unenhanced attenuation of >10HU in non-contrast CT is indicative. The choice of extra-adrenal tumor imaging is based on location. Functional imaging with positron emission tomography/computed tomography and radionuclide administration improves diagnostic accuracy, especially in extra-adrenal/malignant or familial cases. Surgery is the mainstay treatment when feasible. Preoperative α-adrenergic blockade reduces surgical morbidity. Aggressive metastatic PPGL benefits from systemic chemotherapy, while milder cases can be managed with radionuclides. Short-term postoperative follow-up evaluates the adequacy of resection. Long-term follow-up assesses the risk of recurrence or metastasis. Asymptomatic carriers and their families can benefit from surveillance, with intervals depending on the specific gene mutation. Trials primarily focusing on targeted therapy and radionuclides are currently active. A multidisciplinary approach, correct timing, and personalization are key for successful PPGL management.

Intra-individual qualitative and quantitative comparison of [68Ga]Ga-DOTATATE PET/CT and PET/MRI

Background

Somatostatin receptor (SSTR) positron emission tomography (PET) is a cornerstone of neuroendocrine tumor (NET) management. Hybrid PET/magnetic resonance imaging (MRI) is now available for NET-imaging, next to PET/computed tomography (CT).

Objectives

To determine whether CT or MRI is the best hybrid partner for [68Ga]Ga-DOTATATE PET.

Design

Monocentric, prospective study.

Methods

Patients received a same-day [68Ga]Ga-DOTATATE PET/CT and subsequent PET/MRI, for suspicion of NET, (re)staging or peptide receptor radionuclide therapy-selection. The union (PETunion) of malignant lesions detected on PETCT and PETMRI was the reference standard. Concordance of detection of malignant lesions in an organ was measured between PETunion and CT and PETunion and MRI. Seven bins were used to categorize the number of malignant lesions, containing following ordinal variables: 0, 1, 2-5, 6-10, 11-20, >20 countable and diffuse/uncountable. The difference in number of malignant lesions was obtained as the difference in bin level ('Δbin') between PETunion and CT and PETunion and MRI with a Δbin closer to zero implying a higher concordance rate.

Results

Twenty-nine patients were included. Primary tumors included 17 gastroenteropancreatic-NETs, 1 colon neuroendocrine carcinoma, 7 lung-NETs and 2 meningiomas. Patient level concordance with PETunion was 96% for MRI and 67% for CT (p = 0.039). Organ level concordance with PETunion was 74% for MRI and 40% for CT (p < 0.0001). In bone, there was a higher concordance rate for MRI compared to CT, 92% and 33%, respectively (p = 0.016). Overall, a mean Δbin of 0.5 ± 1.1 for PETunion/MRI and 1.4 ± 1.2 for PETunion/CT (p < 0.0001) was noted. In liver, a mean Δbin of 0.0 ± 1.1 for PETunion/MRI and 1.7 ± 1.2 for PETunion/CT was observed (p = 0.0078). In bone, a mean Δbin closer to zero was observed for PETunion/MRI compared to PETunion/CT, 0.6 ± 1.4 and 2.0 ± 1.5, respectively (p = 0.0098).

Conclusions

Compared to SSTR PET/CT, SSTR PET/MRI had a higher patient and organ level concordance for malignant tumoral involvement and number of malignant lesions, with a clear added value in bone and liver specifically.

Management of small cell lung cancer complicated with paraneoplastic Cushing's syndrome: a systematic literature review

Paraneoplastic Cushing's syndrome (PCS) is a rare, but clinically important feature of small cell lung cancer (SCLC) that is associated with even worse prognosis. To identify key considerations in comprehensive management of SCLC patients complicated with PCS, we conducted a systematic review of relevant reports on PubMed and Web of Science, focusing on SCLC with PCS cases. The systematic review analyzed 61 reports published between 1985 and 2022 with a total of 157 SCLC patients included. Out of the 157 patients, 132 (84.1%) patients across 58 (95.1%) reports were diagnosed with ectopic Cushing's syndrome. The immunohistochemical (IHC) staining for adrenocorticotropic hormone (ACTH) was performed on 30 (19.1%) patients across 22 (36.1%) reports and demonstrated encouraging performance. For treatment, chemotherapy and ketoconazole were utilized in 50 (81.97%) and 24 (39.34%) reports, respectively. Regarding cause of death, infection and cancer were equally frequent, each being recorded in 17 (27.87%) reports. To conclude, the majority of PCS cases in SCLC patients were caused by ectopic hormone secretion. In order to make a differential diagnosis, it is recommended to utilize IHC staining for a specific hormone such as ACTH or corticotropin-releasing hormone. In the comprehensive treatment of SCLC with PCS patients, effective management of hypercortisolism and potent safeguarding against infection play two crucial roles. Ultimately, further confirmations are required regarding the specificity and accuracy of IHC staining technique as well as the efficacy and safety of immunotherapy in the treatment of SCLC with PCS patients.

Multiple endocrine neoplasia type 1 with Zollinger-Ellison syndrome: clinicopathological analysis of a Japanese family with focus on menin immunohistochemistry

Background

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the occurrence of multiple epithelial neuroendocrine tumors (NETs) and non-NETs in various organs. MEN1 encodes a 610-amino acid-long tumor suppressor protein, menin. The optimal treatment for multiple tumors, identification of the most critical tumors for patient prognosis, and menin immunohistochemistry findings remain controversial. Therefore, we aimed to elucidate these issues through a histological analysis of tumors and tumor-like lesions in a Japanese family, comprising a father and his two sons, who had MEN1 with Zollinger-Ellison syndrome (ZES).

Patients and methods

All family members had a germline alteration in exon 10, c.1714-1715 del TC of MEN1, and exhibited multiple synchronous and metachronous tumors. The patients had pulmonary NETs, hyperparathyroidism, hypergastrinemia, pituitary adenomas, pancreaticoduodenal NETs, adrenocortical adenoma with myelolipoma, nodular goiter of the thyroid, lipomas, and angiofibroma. Most tumors were resected and histologically examined. We compared their clinical courses and tumor histology, and conducted menin immunohistochemistry (IHC).

Results

Two patients died of pulmonary NET G2. One patient who underwent pancreaticoduodenectomy was cured of ZES; however, the two other patients who did not undergo pancreaticoduodenectomy suffered persistent ZES despite treatment with octreotide. Menin IHC revealed varying NET intensities, ranging from positive to negative stains.

Conclusion

Pancreaticoduodenectomy is the most effective treatment for ZES. Long-term follow-up is essential for pulmonary NET G2 owing to the risk of distant metastasis and/or multiplicity. Moreover, the variability of menin IHC in MEN1-related tumors may indicate the pattern of tumor formation rather than the diagnostic utility of menin in MEN1.

Monitoring and Surveillance of Patients with Gastroenteropancreatic Neuroendocrine Tumors Undergoing Radioligand Therapy

Radioligand therapy (RLT) with [177Lu]Lu-DOTA-TATE is a standard of care for adult patients with somatostatin-receptor (SSTR)-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Taking advantage of this precision nuclear medicine approach requires diligent monitoring and surveillance, from the use of diagnostic SSTR-targeted radioligand imaging for the selection of patients through treatment and assessments of response. Published evidence-based guidelines assist the multidisciplinary healthcare team by providing acceptable approaches to care; however, the sheer heterogeneity of GEP-NETs can make these frameworks difficult to apply in individual clinical circumstances. There are also contradictions in the literature regarding the utility of novel approaches in monitoring and surveilling patients with GEP-NETs receiving RLT. This article discusses the emerging evidence on imaging, clinical biochemistry, and tumor assessment criteria in the management of patients receiving RLT for GEP-NETs; additionally, it documents our own best practices. This allows us to offer practical guidance on how to effectively implement monitoring and surveillance measures to aid patient-tailored clinical decision-making.

Hepatic Glucagonoma in a Post-bariatric Female Patient: A Case Report

Glucagonomas, neuroendocrine tumors originating from the pancreas marked by excessive glucagon secretion, present a diagnostic challenge due to their rarity and diverse symptomatology. In this report, we present a 47-year-old female with a history of bariatric surgery, diabetes mellitus, and deep vein thrombosis who exhibited weight loss, anemia, migratory necrolytic erythema on the lower limbs and groin, and fecal incontinence. Imaging revealed liver secondary lesions without an identifiable primary tumor. After undergoing surgery, a pathologic examination of the excised tissue confirmed that the lesions were a glucagonoma. This case underscores the imperative of how common side effects of bariatric surgery could mask symptoms, delaying the diagnosis of glucagonomas.

ACTH-secreting pancreatic neuroendocrine neoplasms: A case-series

Ectopic Cushing's syndrome (CS) occurs rarely in patients with pancreatic neuroendocrine neoplasms. Early recognition of symptoms is critical given the high morbidity and mortality associated with CS. A database of pancreatic neuroendocrine neoplasms (NENs) seen at the Moffitt Cancer Center between 1/2008 and 4/2022 was reviewed and cases of ectopic CS were identified. Information was extracted on tumor characteristics, clinical signs and symptoms, therapies, and outcomes. Thirteen cases were identified, ranging in age from 16 to 65 years at the initial time of diagnosis (median 42). Twelve of 13 patients had metastatic tumors at presentation. All were well-differentiated at diagnosis although two were described as transformed to poorly differentiated on rebiopsy. A total of 4 patients also experienced Zollinger-Ellison syndrome. Three patients underwent bilateral adrenalectomy to manage uncontrolled CS. Median overall survival of was 56 months from the time of initial cancer diagnosis but only 18 months from diagnosis of CS. Our study showed that ectopic CS is a highly morbid condition when occurring in pancreatic NENs and is associated with aggressive disease. Bilateral adrenalectomy can be considered for syndrome control. To our knowledge, this is the largest institutional case-series of ACTH-secreting metastatic pancreatic NEN.

When is surgery indicated in metastatic small intestine neuroendocrine tumor?

Small intestine neuroendocrine tumors are predominantly small but with high potential for distant metastases development. Diagnosis establishment in early-stage is often difficult and challenging. Small intestine neuroendocrine tumors often initially present with liver metastases. According to the Consensus Guidelines of the North American Neuroendocrine Tumor Society, in patients with liver metastases from unknown origin of primary neuroendocrine tumor, surgical exploration should be performed in order to identify the primary location, prevent small intestine obstruction, and treat one if already present. We present a case of a 69-year-old male patient diagnosed with liver and peritoneal metastases due to small bowel neuroendocrine tumor treated with surgery due to the presence of small intestine obstruction.

The prognostic impact of a high number of peritumoral alveolar macrophages in neuroendocrine carcinoma in the lung

Alveolar macrophages (AMs) are resident macrophages in the lungs; however, whether the number of AMs plays a role in the lung neuroendocrine tumor (NET) prognosis remains unclear. We counted the number of AMs located around the tumor (peritumoral alveolar macrophages [pAMs]) and the number of AMs located apart from the tumor (distant macrophages; dAMs). In 73 cases of neuroendocrine carcinoma (NEC: small cell lung carcinoma and large cell neuroendocrine carcinoma), the group that contained higher pAMs (≥86/μm2 ) revealed shorter recurrent-free survival (RFS) than those with lower pAMs (<86/μm2 ) (p = 0.005). Bivariate analysis showed that the number of pAMs was an independent predictor of a poor RFS. In contrast, in the carcinoid tumor cohort (n = 29), there was no statistically significant correlation between the two groups with high and low numbers of pAMs in RFS (p = 0.113). Furthermore, we examined the correlation between genomic alterations and the number of pAMs in NEC, but no significant correlation was observed. In conclusion, the number of pAMs is a prognostic factor for NEC in the lung and pAMs may contribute to tumor progression within the peritumoral microenvironment.

ACTH-producing small cell neuroendocrine carcinoma from the gallbladder: a case report and literature review

Ectopic adrenocorticotropic hormone syndrome (EAS) is a condition of hypercortisolism caused by non-pituitary tumors that secrete adrenocorticotropic hormone (ACTH). A rare occurrence of this syndrome is due to an ACTH-producing neuroendocrine tumor that originates from the gallbladder. One patient with severe hypokalemia and alkalosis was admitted to our hospital. Clinical presentations and radiographic findings confirmed the diagnosis of an aggressive ACTH-producing gallbladder malignancy with multiple liver metastases. The diagnosis was verified by pathological and immunohistochemical measurements from a biopsy of the hepatic metastasis. A literature review identified only four similar cases had been reported. Despite being rare and having a poor prognosis, hormone-producing neuroendocrine tumors that derive from the gallbladder should be considered in the differential diagnosis of ectopic ACTH syndrome.

Reporting Trends, Practices, and Resource Utilization in Neuroendocrine Tumors of the Prostate Gland: A Survey among Thirty-Nine Genitourinary Pathologists

Background. Neuroendocrine differentiation in the prostate gland ranges from clinically insignificant neuroendocrine differentiation detected with markers in an otherwise conventional prostatic adenocarcinoma to a lethal high-grade small/large cell neuroendocrine carcinoma. The concept of neuroendocrine differentiation in prostatic adenocarcinoma has gained considerable importance due to its prognostic and therapeutic ramifications and pathologists play a pivotal role in its recognition. However, its awareness, reporting, and resource utilization practice patterns among pathologists are largely unknown. Methods. Representative examples of different spectrums of neuroendocrine differentiation along with a detailed questionnaire were shared among 39 urologic pathologists using the survey monkey software. Participants were specifically questioned about the use and awareness of the 2016 WHO classification of neuroendocrine tumors of the prostate, understanding of the clinical significance of each entity, and use of different immunohistochemical (IHC) markers. De-identified respondent data were analyzed. Results. A vast majority (90%) of the participants utilize IHC markers to confirm the diagnosis of small cell neuroendocrine carcinoma. A majority (87%) of the respondents were in agreement regarding the utilization of type of IHC markers for small cell neuroendocrine carcinoma for which 85% of the pathologists agreed that determination of the site of origin of a high-grade neuroendocrine carcinoma is not critical, as these are treated similarly. In the setting of mixed carcinomas, 62% of respondents indicated that they provide quantification and grading of the acinar component. There were varied responses regarding the prognostic implication of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and for Paneth cell-like differentiation. The classification of large cell neuroendocrine carcinoma was highly varied, with only 38% agreement in the illustrated case. Finally, despite the recommendation not to perform neuroendocrine markers in the absence of morphologic evidence of neuroendocrine differentiation, 62% would routinely utilize IHC in the work-up of a Gleason score 5 + 5 = 10 acinar adenocarcinoma and its differentiation from high-grade neuroendocrine carcinoma. Conclusion. There is a disparity in the practice utilization patterns among the urologic pathologists with regard to diagnosing high-grade neuroendocrine carcinoma and in understanding the clinical significance of focal neuroendocrine cells in an otherwise conventional acinar adenocarcinoma and Paneth cell-like neuroendocrine differentiation. There seems to have a trend towards overutilization of IHC to determine neuroendocrine differentiation in the absence of neuroendocrine features on morphology. The survey results suggest a need for further refinement and development of standardized guidelines for the classification and reporting of neuroendocrine differentiation in the prostate gland.

Head-to-Head Comparison of 68Ga-NODAGA-JR11 and 68Ga-DOTATATE PET/CT in Patients with Metastatic, Well-Differentiated Neuroendocrine Tumors: Interim Analysis of a Prospective Bicenter Study

The current study aimed to compare 68Ga-NODAGA-Cpa-cyclo(d-Cys-amino-Phe-hydroorotic acid-d-4-amino-Phe(carbamoyl)-Lys-Thr-Cys)-d-Tyr-NH2 (JR11) and 68Ga-DOTATATE PET/CT in patients with metastatic, well-differentiated neuroendocrine tumors. Methods: A prospective bicenter study aimed at enrolling 100 patients with histologically proven, metastatic or unresectable, well-differentiated neuroendocrine tumors was conducted. The first 48 patients represented the study cohort. Each patient received 68Ga-DOTATATE on the first day and 68Ga-NODAGA-JR11 on the second day. Whole-body PET/CT scans were performed at 40-60 min after injection. Normal-organ uptake, lesion numbers, lesion uptake, and sensitivity were compared. The potential impact on clinical management was also determined. Results: Overall, 68Ga-NODAGA-JR11 demonstrated lower background uptake in normal organs. Compared with 68Ga-DOTATATE, 68Ga-NODAGA-JR11 detected significantly more liver lesions (673 vs. 584, P = 0.002). The target-to-background ratio of liver lesions was significantly higher on 68Ga-NODAGA-JR11 (6.4 ± 8.7 vs. 3.1 ±2.6, P = 0.000). Comparable uptake was observed for primary tumors, bone lesions, and lymph node metastases. In total, 180 lesions were detected on conventional imaging in 15 patients; 165 and 139 lesions of them were positive on 68Ga-NODAGA-JR11 and 68Ga-DOTATATE, leading to a sensitivity of 91.7% and 77.2%, respectively. In 14.5% (7/48) of patients, 68Ga-NODAGA-JR11 PET might have a potential impact on clinical management. Conclusion: 68Ga-NODAGA-JR11 shows better sensitivity and a higher target-to-background ratio than 68Ga-DOTATATE. The detection of more lesions by the antagonist may have a potential impact on clinical management in a subgroup of patients.

Definitive Treatment of Brain Metastases From a Neuroendocrine Tumor With Peptide Receptor Radionuclide Therapy With 177Lutetium DOTATATE: A Case Report

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare malignancies that arise from secretory endocrine cells of the gastroenteropancreatic system. Clinical outcomes have improved for patients with GEP-NETs due to the development and recent FDA approval of 177Lutetium DOTATATE. However, the response of brain metastases from GEP-NETs from 177Lutetium DOTATATE is unreported. We present the case of an 81-year-old man with low-grade small bowel GEP-NET with liver and brain metastases treated with a total of six cycles of 177Lutetium DOTATATE. With over three years of follow-up from his initial treatment, his brain metastases have had complete or partial responses, with no need for brain radiotherapy or radiosurgery.

Management of a Complex Case of a Recurrent Paraganglioma

Paragangliomas are rare, slow-growing, hypervascular, catecholamine-secreting neuroendocrine tumors arising from the paraganglia. Paragangliomas are rarely found in the head and neck and are typically benign, presenting as a painless, slow-growing mass. Surgical extirpation in combination with long-term surveillance has been long regarded as the standard of care; however, the advances in imaging, radiation therapy, and embolization techniques have improved diagnostic and therapeutic modalities. We present a case of an 87-year-old female who had previously undergone resection of a paraganglioma in 1998, with no evidence of disease in 2002. Eighteen years later, the patient presented to the clinic with otogenic complaints. Imaging showed an expansive mass from the jugular foramen with bone destruction and opacification within the ear canal. The patient opted for observation. The patient eventually presented to the emergency room with neurologic manifestations. Imaging showed a cerebellar abscess prompting emergency drainage. Intraoperative cultures grew Prevotella loescheii and S. intermedius, and the patient was started on 6 weeks of IV antibiotic therapy. Debulking of the paraganglioma was performed followed several months by mastoid and ear canal obliteration; however, the patient experienced complications, including dehiscence of the external auditory canal and Clostridium difficile infection. The patient was eventually treated successfully, marked by a reduction in complaints, a return to baseline activities, and imaging showing no increase in tumor size.

New horizon of radiopharmaceuticals in management of neuroendocrine tumors

Neuroendocrine neoplasms are rare and heterogenous group of tumors with varying degrees of clinical presentations and involvement of multiple organ systems in the body. In the modern clinical practice somatostatin receptor molecular imaging and targeted radioligand therapy plays a vital role in the diagnosis and management of the disease. Several new and promising radiotracers for NET imaging and theranostics, belonging to various groups and classes are being studied and investigated. This exponential growth of radiotracers poses concerns about the indication, clinical benefit, and safety profile of the agents. We discuss the basis behind these radiotracers clinical use, receptor targeting and intra and inter tumor heterogeneity. Furthermore, role of dual tracer imaging, combination therapy and potential applications of dosimetry in predicting treatment outcome and safety profile is reviewed. Individualized precision medicine with better tumor characterization, maximum therapeutic benefit and minimum toxicity is the way forward for future medicine.

Slow and Steady: A Slowly Progressing Neuroendocrine Tumor

Neuroendocrine tumors (NETs) are rare malignant tumors that arise from neuroendocrine cells throughout the body, most commonly in the gastrointestinal and respiratory tracts. We report a case of well-differentiated grade 2 NET with a computed tomography scan showing multiple liver lesions consistent with the liver lesions seen 11 years before diagnosis. This case highlights the possibility of an indolent or prolonged clinical course of metastatic NET with an unknown primary vs primary hepatic NET.

Gastroenteropancreatic Neuroendocrine Tumor Metastasis to the Heart: Evaluation of Imaging Manifestations

Neuroendocrine tumors (NET) may affect the heart by cardiac metastasis or carcinoid heart disease. NET metastasis to the heart is rare, with limited data characterizing it. We sought to evaluate 68Ga-DOTATATE PET scan imaging features and associated cardiac imaging characteristics where available in those with NET cardiac metastases. 68Ga-DOTATATE positron emission tomography (PET)/CT scans performed on patients with gastroenteropancreatic (GEP) NET at our institution were reviewed for cardiac involvement. Those identified with cardiac metastases had their electronic medical record, transthoracic echocardiogram (TTE) and cardiac magnetic resonance imaging (MRI) reviewed for characterization. From a total of 1426 68Ga-DOTATATE PET/CT scans performed on patients with GEP-NET, 25 (1.75%) had cardiac uptake consistent with metastasis. Of these, 22 had myocardial metastases (29 distinct myocardial lesions: left ventricle - 16, right ventricle - 6, and ventricular septum -7) and 3 had periradial lymph node involvement only. NET patients with cardiac metastases as identified by DOTATATE scan did not appear to have any hemodynamically significant TTE features, aside from those (2/25) who had concomitant carcinoid heart disease. Of the 14 patients who had available TTE for review, only one with high metastatic cardiac tumor burden had detectable cardiac mass. Of the 6 cases who had available MRI, all had metastatic cardiac lesions seen with excellent correlation with tumor localization on 68Ga-DOTATATE PET scan. 68Ga-DOTATATE PET has excellent capability for the diagnosis of cardiac NET metastasis. Cardiac MRI may provide further anatomic and tissue characterization evaluation. Those with myocardial NET metastases without carcinoid heart disease did not have significant hemodynamic effect based on echocardiographic criteria.

Understanding the increasing incidence of neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors (NETs) are a diverse group of tumors with origins from different primary sites such as gastro-entero-pancreatic, lung and endocrine tissue. Worldwide, their incidence has increased in recent decades. Advances in imaging and better clinical awareness are traditionally attributed to this trend; however, other factors such as genetic and environmental contributors are appreciated as well.

AREAS COVERED

The purpose of this article is to review the worldwide epidemiologic trends in incidence of NET through the decades and discuss the various factors potentially contributing to the observed changes in incidence trends.

EXPERT OPINION

Overall, the incidence of NET has increased across the globe over the last few decades. Although multiple genetics and environmental factors have been proposed, the majority of this increase in incidence is secondary to earlier detection. Future studies will help in more accurate assessments and an improved understanding of disease incidence among patients with different grades and differentiation.

A Case of Functional Bowel Disease Misdiagnosed as Carcinoid Syndrome

An elevated urinary 5-hydroxyindoleacetic acid (U5-HIAA) is typically thought of to be related to carcinoid syndrome. It is widely known that several other etiologies can cause high levels; however, those etiologies typically cause mild elevations. We present a unique situation of a highly elevated U5-HIAA not because of a neuroendocrine tumor. Gastroenterologists need to have an approach in mind if they encounter this predicament. We aim to raise awareness of this situation to emphasize the importance of a thorough medication history and avoid unnecessary testing.

Management of non-hepatic distant metastases in neuroendocrine neoplasms

Neuroendocrine neoplasms represent an uncommon disease with an increasing incidence. Thanks to improvements in diagnostic and therapeutic methods, metastases previously considered uncommon, such as bone metastases, or even very rare, such as brain, orbital and cardiac metastases, are more frequently found in daily practice. Due to the great heterogeneity of these neoplasms, there is a lack of high-quality evidence on the management of patients with these types of metastases. The aim of this review is to provide the current state of the art, reviewing neuroendocrine neoplasm specific studies and useful information from other tumor types and to propose a treatment recommendation with algorithms to consider in daily clinical practice.

Small Bowel Neuroendocrine Tumors-10-Year Experience of the Ottawa Hospital (TOH)

(1) Aim: The prevalence and incidence of small bowel NETs have increased significantly over the past two decades. This study aims to report the 10-year experience of SB-NET management at a regional cancer center in Canada. (2) Materials and methods: We conducted a retrospective study of the clinical and pathological data of patients diagnosed with biopsy-proven SB-NET at The Ottawa Hospital (TOH), Ottawa, Canada between 2011 and 2021. We report the clinicopathological characteristics of these patients, as well as their outcomes data, including survival rates. (3) Results: Between 2011 and 2021, a total of 177 SB-NET cases were identified with 51% (n = 91) of cases being males. The most common sites of the tumors were the ileum 53% (n = 94), followed by the duodenum 9% (n = 16) and jejunum 7% (n = 12). Approximately 24% (n = 42) of the patients had symptoms for over six months prior to diagnosis and 18% (n = 32) had functioning SB-NET during the course of the disease. The majority of patients had locally advanced or metastatic disease at the time of presentation with stage III, and stage IV representing 42% (n = 75), and 41% (n = 73) respectively. The majority of patients 84% (n = 148) had well-differentiated histology. One hundred twenty patients underwent surgical resection of the primary tumor including 28 patients (16%) with limited metastatic disease. A total of 21 patients (18%) had recurrence after curative surgery. A total of 62 patients (35%) received first-line somatostatin analog (SSA) therapy for unresectable disease and seven patients had PRRT after progression on SSA. Five years OS was 100%, 91%, 97%, and 73% for stages I, II, III, and IV respectively. In univariate analysis, carcinoid symptoms, T stage, and differentiation were significant predictors for worse overall survival, but not RFS. (4) Conclusions: Compared to published historical controls, our study suggests improvement in the 5-year survival rate of SB-NETs over the last 10 years.

Conventional Transarterial Chemo embolization Using Streptozocin in Patients with Unresectable Neuroendocrine Liver Metastases

BACKGROUND

The purpose of this study was to evaluate the clinical, biological and radiological responses to, and tolerability of, conventional transarterial chemoembolization (cTACE) using streptozocin for unresectable neuroendocrine liver metastases.

PATIENTS AND METHODS

A total of 52 patients with predominant liver disease were treated with cTACE using an emulsion of streptozocin, Lipiodol and embolization particles. A sequential approach was favored in patients with high liver tumor burden. Clinical, biological and radiological responses were evaluated using carcinoid symptoms, biomarkers and mRecist criteria, respectively.

RESULTS

A total of 127 procedures were performed with a sequential approach in 65% of patients. All patients received streptozocin and Lipiodol. Carcinoid syndrome was improved in 69% of patients after treatment (p = 0.01). Post-embolization syndrome was reported in 78% of patients. At the end of all cTACE, objective response and non-progressive disease were 32% and 70%, respectively. Progression-free survival was 18.3 ± 13.3 months (median 14.9) and median overall survival (OS) from start of treatment was 74 months. The OS at 1 year, 2 years, 3 years and 5 years was 91% (IC = 84-99%), 84% (CI = 72-95%), 69% (CI = 53-84%) and 63% (C = 46-81%), respectively.

CONCLUSIONS

cTACE using streptozocin is an effective and well-tolerated palliative option for patients with neuroendocrine liver metastases, associated with prolonged survival and delayed time to progression.