Clinical presentation and evaluation of neuroendocrine tumors of the lung

Preclinical Models of Neuroendocrine Neoplasia

Neuroendocrine neoplasia (NENs) are a complex and heterogeneous group of cancers that can arise from neuroendocrine tissues throughout the body and differentiate them from other tumors. Their low incidence and high diversity make many of them orphan conditions characterized by a low incidence and few dedicated clinical trials. Study of the molecular and genetic nature of these diseases is limited in comparison to more common cancers and more dependent on preclinical models, including both in vitro models (such as cell lines and 3D models) and in vivo models (such as patient derived xenografts (PDXs) and genetically-engineered mouse models (GEMMs)). While preclinical models do not fully recapitulate the nature of these cancers in patients, they are useful tools in investigation of the basic biology and early-stage investigation for evaluation of treatments for these cancers. We review available preclinical models for each type of NEN and discuss their history as well as their current use and translation.

Classifying Pulmonary and Urinary High-grade Neuroendocrine Carcinoma by CK7 Immunohistochemistry

High-grade neuroendocrine carcinoma (HGNEC) is subclassified into small cell carcinoma (SmCC) and large cell neuroendocrine carcinoma (LCNEC). Although both are clinically aggressive, the SmCC and LCNEC need to have different treatment strategies, and accurate pathologic diagnosis is challenging. We studied a large retrospective cohort (186 cases) of HGNEC of bladder and lung to investigate the abundance of cytokeratin (CK) 7 expression and staining pattern in SmCC and LCNEC. Overall, the pulmonary and urinary HGNEC exhibited several different CK7 staining patterns, including negative staining (n=28), dot-like staining (n=73), partial membranous staining (n=26), and complete membranous staining (n=60). Overall, 88.9% (44/49) of pulmonary SmCC and 88.0% (44/50) of urinary SmCC showed negative or dot-like patterns for CK7, while 90.8% (59/65) of pulmonary LCNEC and 72.7% (16/22) of urinary LCNEC showed partial or complete membranous patterns for CK7 (χ 2 =105.05, P <0.0001). The distinct staining patterns were also present in those mixed SmCC and LCNEC. In addition, the specimen types or fixation did not affect CK7 staining patterns. In conclusion, CK7 has a high differential value for SmCC and LCNEC and could help guide personalized treatment for patients.

Clinicopathological, Oncogenic, and 18F-FDG PET/CT Features of Primary Pulmonary Carcinoid in Resection Specimens

Objectives

The metabolic parameters which included mean standardised uptake value (SUVmean), metabolic tumour volume (MTV), total lesion glycolysis (TLG), maximum standardised uptake lean body mass (SULmax), and maximum standardised uptake body surface area (SUVbsa) have rarely been investigated in pulmonary carcinoid (PC). This study aimed to retrospectively compare the ¹⁸F-FDG PET/CT features of PC subtypes and observe clinicopathological and oncogenic characteristics of PC.

Methods

We performed a retrospective review in 60 patients with PC, from January 2016 to November 2021, who underwent the ¹⁸F-FDG PET/CT scan. All the PC diagnoses were histopathologic confirmed by surgical samples. The metabolic and morphological features were obtained from ¹⁸F-FDG PET/CT images. The ratio of metabolic to morphological lesion volumes (MMVR) was calculated.

Results

Sixty patients with PC were consecutively identified, including 39 patients (65.0%) with typical carcinoids (TCs) and 21 (35.0%) with atypical carcinoids (ACs). One (1/21) patient had mutation in BRAF. The ACs have a larger size (P < 0.001), more metastatic lymph nodes (P = 0.011), higher Ki-67 expression (P < 0.001), higher SUVmax values (P = 0.003), higher SUVmean values (P = 0.006), higher SULmax values (P = 0.005), higher SUVbsa values (P = 0.001), higher MTV values (P = 0.033), and higher TLG values (P = 0.002). The multivariate analysis showed that MMVR (P = 0.020) was significantly associated with AC. For predicting AC, the optimal cut-off value of SUVmax, SUVmean, SULmax, SUVbsa, MTV, TLG, and the maximum diameter was 5.19, 3.18, 2.65, 1.47, 4.36, 18.44, and 3.0, respectively. The AUC values of above mentioned parameters was 0.756 (95%CI, 0.631–881; P = 0.001), 0.735 (95%CI, 0.602–868; P = 0.003), 0.736 (95%CI, 0.607–865; P = 0.003), 0.742 (95%CI, 0.612–873; P = 0.002), 0.593 (95%CI, 0.430–755; P = 0.239), 0.680 (95%CI, 0.531–829; P = 0.022), and 0.733 (95%CI, 0.598–868; P = 0.003), respectively. For predicting TC, the optimal cut-off value of the MMVR was 0.92, and the AUC value was 0.780 (95%CI, 0.647–0.913; P < 0.001).

Conclusion

¹⁸F-FDG PET/CT can simultaneously reveal the metabolic and morphological characteristics of PC, which is important in the differentiation for histopathologic subtypes.

Epidemiological analysis of lung and mediastinal neuroendocrine neoplasms in Japan based on the national database

BACKGROUND

Neuroendocrine neoplasms (NENs) are rare and can originate from any body part. However, there are only few epidemiological studies, especially on lung and mediastinal NENs. This study investigated the epidemiological trends and differences between lung and mediastinal NENs in Japan.

METHODS

Patients with lung and mediastinal NENs were identified in a national hospital-based cancer registry between 2009 and 2015 in Japan. NENs were subclassified into neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs). NECs were further subdivided into large neuroendocrine carcinomas (LCNECs) and small cell carcinomas (SCCs). We examined the patient characteristics: sex, age, histology, year of diagnosis, diagnostic opportunity, and initial treatment.

RESULTS

We identified 48,433 patients with 47,888 lung (98.9%) and 545 mediastinal (1.1%) NENs. The commonest subtype of lung NENs was SCCs (87%), followed by LCNECs (10%) and NETs (3%). In the mediastinum, SCCs were also the commonest (48%), followed by NETs (38%) and LCNECs (14%). The number of lung NEN annually increased; however, that of mediastinal NENs did not change over time. The mean age of patients with lung NETs was lower than that of patients with lung LCNECs and SCCs (NETs, 62 ± 14 years; LCNECs, 70 ± 9 years; SCCs, 71 ± 9 years; p < .001). The lung and mediastinal NENs were mainly detected based on symptoms, except for lung NETs. Surgical intervention, including multimodal therapy, was performed for 89.3% of lung NETs (surgery alone: 83.6%), while only 15.6% of lung NECs were treated with surgery. For the mediastinum, 75.9% of NETs were treated with surgery, with 27.1% of cases treated with surgery plus multimodal therapy. Surgery was performed more frequently for mediastinal NECs (37%) than for lung NECs (15.6%).

CONCLUSIONS

This study highlights differences in trends of lung and mediastinal NENs. This study's findings support the importance of epidemiological evaluations based on the primary sites and histological subtypes.

Long-term survival and recurrence after resection of bronchopulmonary carcinoids: A single-center cohort study of 236 patients

OBJECTIVE

The aim of this study was to determine overall survival and recurrence-free survival after resection of bronchopulmonary carcinoids by means of predominantly minimally invasive surgery and lung-sparing resections. In addition, we aimed to identify prognostic factors for overall survival.

MATERIALS AND METHODS

Retrospective review of consecutive patients operated for bronchopulmonary carcinoids between January 2009 and October 2020 identified from a prospectively collected database.

RESULTS

A total of 236 patients representing 240 cases of bronchopulmonary carcinoids were included. Of these, 212 (88.3 %) were typical carcinoids, while 28 (11.7 %) were atypical carcinoids. A Video-Assisted Thoracoscopic Surgery (VATS) approach was used in 75 % of cases. There was no 30-day mortality. The median follow-up was 5.6 years for overall survival and 4.7 years for recurrence-free survival. 5- and 10-year overall survival rates were 89 % and 71 %, while 5- and 10-year recurrence-free survival rates were 84 % and 71 %. Patients with atypical carcinoids had significantly reduced overall survival and recurrence-free survival rates (HR 3.4; 95 % CI 1.5-7.6; p = 0.003 and HR 5.4; 95 % CI 2.6-11.4; p < 0.001). Independent predictors of overall survival included atypical carcinoid (HR 2.7; 95 % CI 1.2-6.0; p = 0.018) and age > 60 years (HR 2.9; 95 % CI 1.2-7.3; p = 0.021).

CONCLUSION

Surgery for bronchopulmonary carcinoids by means of predominantly VATS and lung-sparing resections provides favorable long-term survival. Atypical carcinoids and age > 60 years are independent predictors of poor overall survival.

A National Study of Surgically Managed Atypical Pulmonary Carcinoid Tumors

BACKGROUND

Atypical pulmonary carcinoid tumors represent a subset of non-small cell lung cancer; however, their relative infrequency has left prognosis, management and long-term survival associated with atypical carcinoids, incompletely characterized.

METHODS

Patients aged 18 years or more diagnosed with atypical or typical pulmonary carcinoid between 2010 and 2015 within the National Cancer Database were evaluated. Survival was measured using Kaplan-Meier survival and multivariable Cox proportional hazards regression, adjusting for patient and tumor attributes.

RESULTS

A total of 816 atypical and 5688 typical carcinoid patients were identified in the cohort. Patients with atypical carcinoids tended to be older, have larger tumors, and later stage disease. The unadjusted overall 5-year survival for atypical carcinoid patients was 84%, 74%, 52%, and 51% for stages I, II, III, and IV, respectively. The unadjusted 5-year survival for typical carcinoids was 93%, 93%, 89%, and 87% for stages I, II, III, and IV, respectively. Nodal upstaging (ie, lymph node metastases identified in surgical specimens of clinically staged N0 patients) was seen in 16% of atypical and 7% of typical carcinoid patients. Increasing age, comorbidities, and stage were identified as significant predictors of mortality for atypical patients in multivariable analysis. Extent of surgical resection (lobectomy vs sublobar) was not identified as a predictor of survival for atypical carcinoid.

CONCLUSIONS

Atypical carcinoid tumors represent a distinct subset of carcinoid tumors, with a tendency toward more aggressive behavior. Further study of the optimal surgical management is warranted.

Improved Therapeutic Efficacy of Topotecan Against A549 Lung Cancer Cells with Folate-targeted Topotecan Liposomes

BACKGROUND

Among all cancers, lung cancer has high mortality among patients in most of the countries in the world. Targeted delivery of anticancer drugs can significantly reduce the side effects and dramatically improve the effects of the treatment. Folate, a suitable ligand, can be modified to the surface of tumor-selective drug delivery systems because it can selectively bind to the folate receptor, which is highly expressed on the surface of lung tumor cells.

OBJECTIVE

This study aimed to construct a kind of folate-targeted topotecan liposomes for investigating their efficacy and mechanism of action in the treatment of lung cancer in preclinical models.

METHODS

We conjugated topotecan liposomes with folate, and the liposomes were characterized by particle size, entrapment efficiency, cytotoxicity to A549 cells and in vitro release profile. Technical evaluations were performed on lung cancer A549 cells and xenografted A549 cancer cells in female nude mice, and the pharmacokinetics of the drug were evaluated in female SD rats.

RESULTS

The folate-targeted topotecan liposomes were proven to show effectiveness in targeting lung tumors. The anti-tumor effects of these liposomes were demonstrated by the decreased tumor volume and improved therapeutic efficacy. The folate-targeted topotecan liposomes also lengthened the topotecan blood circulation time.

CONCLUSION

The folate-targeted topotecan liposomes are effective drug delivery systems and can be easily modified with folate, enabling the targeted liposomes to deliver topotecan to lung cancer cells and kill them, which could be used as potential carriers for lung chemotherapy.

The "numb chin syndrome": A case report

INTRODUCTION

Neuroendocrine tumours comprise 0.5-2% of all malignancies in adulthood, and very rarely metastasize to the oral cavity. When they do metastasize to the oral cavity, the mandible is the most common site. This can lead to symptoms such as a numb chin and lip, which in the absence of any odontogenic cause may be an important sign indicating malignant disease. We present a rare case of metastatic neuroendocrine carcinoma to the mandible, resulting in the so-called "numb chin syndrome".

PRESENTATION OF CASE

An elderly lady presented with numbness to the right chin and lip, as well as hypoglossal nerve palsy. She had significant back pain and gave a history of repeat chest infections. Intra-oral clinical examination was normal, but upon further special investigations, the right mental region was suspicious of multiple lytic lesion. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) demonstrated marrow changes in the mandible suspicious of malignant disease. Further findings included multiple pathological fractures of the spine and a mass in the left lung base. A trephine biopsy gave a diagnosis of metastatic neuroendocrine carcinoma, with the left lung mass considered to be the primary site.

DISCUSSION

We discuss the rarity of metastatic disease to the oral cavity, and the importance of "numb chin syndrome" in indicating malignancy.

CONCLUSIONS

This case promotes the importance of considering sinister pathology when presented with sudden, altered sensation to the chin and lips. The "numb chin syndrome" should always raise the suspicion of primary or metastatic disease to the mandible.

Metastatic small cell neuroendocrine carcinoma of the submandibular gland from the lung: A case report

RATIONALE

Small cell neuroendocrine carcinoma of the salivary gland is an extremely rare condition. To the best of our knowledge, metastasis of small cell neuroendocrine lung cancer to the submandibular gland has not been reported in the literature.

PATIENT CONCERN

An 87-year-old female complained of a left neck mass that enlarged from one month ago.

DIAGNOSIS

The final diagnosis was diagnosed as a metastatic small cell neuroendocrine carcinoma of the submandibular gland from lung by an immunohistochemistry.

INTERVENTIONS

Left submandibular resection was performed under general anesthesia.

OUTCOMES

We recommended further evaluation and treatment, but the patient and patient family support team rejected further treatment of her condition. It was confirmed that 3 months after this conclusive diagnosis, the patient died as a result of this condition and disease.

LESSONS

Small cell neuroendocrine carcinoma of the salivary gland is an extremely rare condition. We report a case of metastatic small cell neuroendocrine carcinoma of the submandibular gland from the lung.

Systemic treatment for lung carcinoids: from bench to bedside

In the huge spectrum of lung neuroendocrine neoplasms, typical and atypical carcinoids should be considered as a separate biological entity from poorly differentiated forms, harboring peculiar molecular alterations. Despite their indolent behavior, lung carcinoids correlate with a worse survival. To date, only limited therapeutic options are available and novel drugs are strongly needed. In this work, we extensively reviewed scientific literature exploring available therapeutic options, new molecular targets and future perspectives in the management of well differentiated neoplasms of bronchopulmonary tree. Systemic therapy represents the main option in advanced and unresectable disease; accepted choices are somatostatin analogs, peptide receptor radionuclide therapy, everolimus and chemotherapy. To date, an univocal treatment strategy has not been identified yet, thus tailored therapeutic algorithms should consider treatment efficacy as well as safety profiles. Several molecular alterations found in carcinoid tumors might act as molecular targets leading to development of new therapeutic options. Further studies are necessary to identify new potential “druggable” molecular targets in the selected subset of low-grade lung carcinoids. Furthermore, evaluating the available therapies in more homogeneous population might improve their efficacy through a perfect tailoring of treatment options.

[Resection concepts for early stage neuroendocrine tumors of the lungs and bronchi]

BACKGROUND

Neuroendocrine tumors of the lungs are a very inhomogeneous group of malignancies. The surgical treatment should be adapted to the anatomical localization and histological subtype and individualized according to the functional reserve.

MATERIAL AND METHODS

We performed a selective review of current literature, which was supplemented by personal experiences.

RESULTS

The currently available outcome data are very inhomogeneous and depend on the histological subtype of neuroendocrine pulmonary tumors. A radical R0 resection is the key for an improvement in long-term overall and disease-free survival.

CONCLUSION

Surgical treatment of carcinoid tumors is the current standard therapy. Sleeve resection should be performed, whenever possible. More aggressive tumors, such as large cell neuroendocrine carcinoma and small cell lung cancer should be treated in a multimodal concept.

Role of wedge resection in bronchial carcinoid (BC) tumors: SEER database analysis

Background

There is a paucity of data regarding the role of wedge resection (WR) in the management of bronchial carcinoid (BC) tumors. In this study, we queried the Surveillance, Epidemiology, and End Results (SEER) database to compare the oncologic outcomes of patients with BC tumors treated with WR or anatomic resection.

Methods

The SEER database was retrospectively reviewed for patients with BC treated with surgical resection between 1973-2013. Patients who underwent WR were compared to those who underwent lobectomy or segmentectomy (Lob/Seg). Patients with multiple primaries and those who underwent pneumonectomy or have an unspecified surgical procedure were excluded. Differences in demographics and clinicopathological data were compared using Chi (χ²) test or Mann Whitney U test. Overall and cancer specific survival (OS, CSS) were estimated using Kaplan-Meier method and differences were compared using log-rank test. Cox-regression multivariable analysis (MVA) was performed to explore factors associated with worse CSS. Propensity-score matching analysis was done to compare survival differences between WR and Lob/Seg.

Results

A total of 22,350 patients with BC were identified, of them 4,450 met our inclusion criteria (3,511 Lob/Seg, vs. 939 WR). The median age was 59.0 years [interquartile range (IQR) =49.0-68.0], 67.6% were females and the median tumor size was 2 cm (1.5-3 cm). 4,119 patients had typical carcinoid (TC) and 331 had atypical carcinoid (AC). WR was performed more frequently in elderly patients, females, lower lobe tumors, TC's and in earlier stage disease. For patients with TC, there was no difference in CSS between WR and Lob/Seg in both the entire cohort (P=0.654) and in the propensity matched groups (P=0.900). However, for patients with AC, Lob/Seg was associated with better CSS compared to WR both in the entire cohort (P<0.001) and in the propensity matched groups (P=0.001). On MVA of the entire cohort, elderly patients, males, blacks, AC and advanced stages had worse CSS. While, the type of the procedure (WR vs. Lob/Seg) was not associated with CSS (HR =1.16, 95% CI: 0.85-1.60).

Conclusions

A WR may offer equivalent CSS in well-selected patients with early-stage TC. An anatomic resection appears warranted in AC.

Characterization, Prognosis, and Treatment of Patients With Metastatic Lung Carcinoid Tumors

INTRODUCTION

Metastatic lung carcinoids (MLCs) remain poorly characterized and no prognostic stratification exists.

METHODS

We conducted a retrospective study including patients with MLCs in two European expert centers. The aims were to characterize these cases and to identify prognostic factors of survival and effectiveness of their treatments.

RESULTS

A total of 162 patients with MLC were included: 50% were women, and the median age was 61 years. Half of the patients had synchronous metastases, mainly located in the liver (75%), bone (42%), and lung (25%). According to WHO classification, MLCs were typical (28%), atypical (60%), or unspecified (12%). A functioning syndrome was observed in 43% of cases and an uptake at somatostatin receptor scintigraphy in 76% of cases. The 5-year overall survival rate was 60% and at 10 years this was 25%. In multivariate analysis, Eastern Cooperative Oncology Group performance status of 0-1 (hazard ratio [HR]: 5.81, 95% confidence interval [CI]: 2.10-16.11), uptake on SRS (HR: 0.38, 95% CI: 0.22-0.66), low serum chromogranin A (HR: 2.27, 95% CI: 1.36-3.81), and typical carcinoid (HR: 1.87, 95% CI: 1.26-2.78) were associated with better survival. According to Response Evaluation Criteria in Solid Tumors version 1.0, the highest objective response rates were obtained after radiofrequency ablation of metastases (86%), liver embolization (56%), peptide receptor radionuclide therapy (27%), and oxaliplatin-based chemotherapy (18%).

CONCLUSIONS

MLCs are characterized by a high frequency of atypical carcinoids, functioning syndrome, and liver/bone metastases. WHO classification, performance status, somatostatin receptor scintigraphy, and chromogranin A were associated with longer survival. Partial response was more frequent with locoregional therapies, peptide receptor radionuclide therapy, or oxaliplatin-based chemotherapy.

Massive hemorrhage after inspection bronchoscopy for carcinoid tumor

Carcinoid tumor is a neuroendocrine tumor that can arise in the bronchial tree and can be hypervascular. Here we describe a case of bronchial carcinoid tumor in a 34-year-old previously healthy male who presented with hemoptysis and right lung mass. Inspection bronchoscopy revealed bronchus intermedius endobronchial lesion and was complicated by urgent intubation and placement of endobronchial blocker for massive hemorrhage. Subsequent angiography with embolization of the bronchial artery supplying the mass resulted in control of bleeding. While massive hemorrhage has been described with biopsy of bronchial carcinoid tumor, this case suggests that careful planning for inspection bronchoscopy is needed when carcinoid tumor is suspected.

Advances on systemic treatment for lung neuroendocrine neoplasms

Lung well-to-moderately differentiated neuroendocrine tumors (also known as carcinoids) and large cell neuroendocrine lung carcinoma (poorly differentiated neuroendocrine tumor) are rare neuroendocrine neoplasms, which account for less than 4% of all lung neoplasms. Due to their low incidence, their systemic treatment is greatly influenced by therapeutic evidence derived from the more frequent gastroenteropancreatic neuroendocrine neoplasms and/or small cell lung carcinoma leading to significant bias. Currently, employed systemic therapies for lung carcinoids, aiming at controlling tumor growth include long acting somatostatin analogues (SSAs), peptide receptor radionuclide therapy, chemotherapy and molecular-targeted therapy. In this review, each of those treatments is presented based upon available clinical evidence from retrospective and prospective studies particularly focused on the role of everolimus in the advanced setting and on ongoing clinical trials reflecting our expectations in the near future. In addition, we critically analyse currently employed treatment of large cell neuroendocrine carcinoma where the appropriate chemotherapeutic regimen is still a matter of debate.

Everolimus in advanced, progressive, well-differentiated, non-functional neuroendocrine tumors: RADIANT-4 lung subgroup analysis

In the phase III RADIANT-4 study, everolimus improved median progression-free survival (PFS) by 7.1 months in patients with advanced, progressive, well-differentiated (grade 1 or grade 2), non-functional lung or gastrointestinal neuroendocrine tumors (NETs) vs placebo (hazard ratio, 0.48; 95% confidence interval [CI], 0.35-0.67; P < .00001). This exploratory analysis reports the outcomes of the subgroup of patients with lung NETs. In RADIANT-4, patients were randomized (2:1) to everolimus 10 mg/d or placebo, both with best supportive care. This is a post hoc analysis of the lung subgroup with PFS, by central radiology review, as the primary endpoint; secondary endpoints included objective response rate and safety measures. Ninety of the 302 patients enrolled in the study had primary lung NET (everolimus, n = 63; placebo, n = 27). Median PFS (95% CI) by central review was 9.2 (6.8-10.9) months in the everolimus arm vs 3.6 (1.9-5.1) months in the placebo arm (hazard ratio, 0.50; 95% CI, 0.28-0.88). More patients who received everolimus (58%) experienced tumor shrinkage compared with placebo (13%). Most frequently reported (≥5% incidence) grade 3-4 drug-related adverse events (everolimus vs. placebo) included stomatitis (11% vs. 0%), hyperglycemia (10% vs. 0%), and any infections (8% vs. 0%). In patients with advanced, progressive, well-differentiated, non-functional lung NET, treatment with everolimus was associated with a median PFS improvement of 5.6 months, with a safety profile similar to that of the overall RADIANT-4 cohort. These results support the use of everolimus in patients with advanced, non-functional lung NET. The trial is registered with ClinicalTrials.gov (no. NCT01524783).

Pediatric neuroendocrine carcinoid tumors: Management, pathology, and imaging findings in a pediatric referral center

BACKGROUND

While neuroendocrine (carcinoid) tumors are increasingly recognized in the adult population, they are often not suspected in children.

PROCEDURE

Retrospective review of all well-differentiated neuroendocrine (carcinoid) tumors was performed based on pathology reports from a quaternary pediatric medical center between January 2003 and June 2016. Clinical presentations, treatment approaches, imaging findings, and outcomes were reviewed and analyzed.

RESULTS

A total of 45 cases of pathology-proven carcinoid tumor were reported with an average age of 14.1 years (range: 7-21 years, SD: 2.8 years). Of these cases, 80% (36) were appendiceal, 11% (5) bronchial, 2% (1) colonic, 2% (1) gastric, 2% (1) enteric, and 2% (1) testicular. Metastases were observed in one (3%) appendiceal, one (100%) enteric, and two (40%) bronchial cases. No recurrence was demonstrated in any appendiceal carcinoid cases. Recurrence was seen in one of three extra-appendiceal gastrointestinal tumors. Tumor site and size significantly correlated with metastases and recurrence.

CONCLUSIONS

Contrary to recent epidemiological investigations in adults, appendiceal carcinoid tumors remain the most common site for pediatric carcinoid tumors. Appendiceal carcinoid tumors exhibited benign clinical courses without recurrence during short-term follow-up. Extra-appendiceal gastrointestinal carcinoid tumors exhibited much more aggressive behavior with greater metastases and recurrence. Bronchial carcinoid tumors demonstrated good clinical response to resection even in cases with mediastinal lymph node involvement. While increased use of urine 5-HIAA levels and somatostatin receptor-specific imaging might improve detection and guide management of extra-appendiceal carcinoid tumors, longer-term follow-up is needed.

Do we really care about incidental lung nodules?-Review of atypical lung carcinoid and a proposal for systematic patient follow up

Atypical lung carcinoids are intermediate-grade neuroendocrine tumors (NETs) with malignant potential. They are often detected incidentally on imaging done for non-related causes, as the patients are frequently asymptomatic. Histopathology is required to confirm the diagnosis with immunohistochemistry (IHC). Due to their indolent nature, these are often diagnosed only in the advanced stages. Treatment options include chemoradiation for widespread disease versus surgery for local or minimally invasive disease. This article describes a nonsmoker female with enlarging solitary pulmonary nodule who was initially lost to follow up, subsequently operated and with final pathology revealing atypical lung carcinoid. This case stress on the schematic follow up of these incidentally detected pulmonary nodules. Inspired from the mandatory lay mammography report letters recommended by ACR, this article proposes sending lay letters to patients for pulmonary nodule follow up, directly from the Radiology Department to reinforce the importance of timely follow up, which will complement the information provided to the patient from their primary care physician or pulmonologist's office.

[Pulmonary carcinoid tumors]

Pulmonary carcinoids are rare low-grade malignant tumors, which arise from the neuroendocrine system. Approximately 80% of all pulmonary carcinoid tumors are the relatively low-grade typical carcinoids and 20% are the more aggressive atypical carcinoids. Most carcinoids arise from the central airways and only a minority of carcinoids are found in the lung periphery. While most of the peripheral carcinoids are asymptomatic, central carcinoids are symptomatic and present with hemoptysis, wheezing or bronchial obstruction. On computed tomography (CT), carcinoids frequently present as hypervascular pulmonary nodules in close proximity to the bronchial system. Due to the bronchial obstruction, many patients with pulmonary carcinoids present with post-obstructive pneumonia or atelectasis. While fluorodeoxyglucose positron emission tomography CT (FDG-PET/CT) is of limited value in typical carcinoids due to the high rate of false negatives, somatostatin analogs are promising tracers in staging as well as in the planning of peptide receptor radionuclide therapy.

Pediatric Neuroendocrine Carcinoid Tumors: Review of Diagnostic Imaging Findings and Recent Advances

OBJECTIVE

Although rare, pediatric neuroendocrine tumors including carcinoid tumor have increased in incidence over the past few decades. Despite increased recognition, survival rates have not significantly improved. Earlier detection of these tumors is necessary to improve clinical outcomes. This article discusses imaging approaches for detecting pediatric carcinoid tumors including anatomic imaging methods such as CT and MRI as well as functional imaging methods targeting the somatostatin receptor including ¹¹¹In-labeled octreotide and newer ⁶⁸Ga-based radiotracers that may hold promise in hybrid PET/CT or PET/MRI.

CONCLUSION

Improvements in functional imaging with novel somatostatin receptor-specific radiotracers along with fused functional and anatomic imaging have substantially improved the clinical detection of carcinoid tumors. Although rare, these tumors are encountered in children, and an awareness of the appropriate use of various imaging methods is essential for pediatric specialists. Further research is needed to ascertain the diagnostic value of newer imaging methods and radiotracer-based treatment approaches, especially in the pediatric population.

Erroneous diagnosis of small cell lung cancer based on small biopsies with far-reaching consequences: case report of a typical carcinoid tumor

Although neuroendocrine tumors (NETs) of the lung are frequently discussed together, carcinoids are very different from high-grade small cell lung carcinoma (SCLC). SCLC is found in heavy-smoking, older patients, whereas smoking is not strongly associated with carcinoid tumors. We present the case of a 46-year-old never smoking woman who was misdiagnosed with SCLC. The patient was not responsive to radio-chemotherapy plus prophylactic cranial irradiation (PCI); she had a typical carcinoid (TC) tumor according to the final pathology report. We aim to demonstrate that diagnosis of SCLC based on cytology or small biopsy specimens must be scrutinized when the clinical constellation is unusual, or when the follow-up assessment shows no response to systemic treatment.

Neuroendocrine Tumors of the Lung: Current Challenges and Advances in the Diagnosis and Management of Well-Differentiated Disease

Neuroendocrine tumors (NETs) comprise a heterogeneous group of malignancies that arise from neuroendocrine cells throughout the body, most commonly originating from the lungs and gastrointestinal tract. Lung NETs can be classified as well differentiated (low-grade typical carcinoids [TCs] and intermediate-grade atypical carcinoids [ACs]) and poorly differentiated (high-grade large cell neuroendocrine carcinoma or SCLC). The incidence of these tumors is increasing, but disease awareness remains low among thoracic specialists, who are often involved in the diagnosis and early treatment for these patients. An accurate and timely diagnosis can ensure the implementation of appropriate treatment and have a substantial impact on prognosis. However, lung NET classification and diagnosis, particularly for TCs/ACs, are complicated by several factors, including a variable natural history and nonspecific symptoms. Surgery remains the only curative option for TCs/ACs, but there is a lack of consensus between lung NET management guidelines regarding optimal treatment approaches in the unresectable/metastatic setting on account of the limited availability of high-level clinical evidence. As a result, a multidisciplinary approach to management of lung NETs is required to ensure a consistent and optimal level of care. RADIANT-4 is the first phase III trial involving a large subpopulation of patients with advanced well-differentiated lung NETs to report reductions in the risk for disease progression and death with everolimus over placebo. This led to the recent U.S. approval of everolimus-the first agent approved for advanced lung TCs/ACs. To further improve evidence-based care, additional randomized controlled trials in patients with lung carcinoids are needed.