Neuroendocrine tumors of the lung: clinical, pathologic, and imaging findings

Diagnostic Anatomic Imaging for Neuroendocrine Neoplasms: Maximizing Strengths and Mitigating Weaknesses

ABSTRACT

Neuroendocrine neoplasms are a heterogeneous group of gastrointestinal and lung tumors. Their diverse clinical manifestations, variable locations, and heterogeneity present notable diagnostic challenges. This article delves into the imaging modalities vital for their detection and characterization. Computed tomography is essential for initial assessment and staging. At the same time, magnetic resonance imaging (MRI) is particularly adept for liver, pancreatic, osseous, and rectal imaging, offering superior soft tissue contrast. The article also highlights the limitations of these imaging techniques, such as MRI's inability to effectively evaluate the cortical bone and the questioned cost-effectiveness of computed tomography and MRI for detecting specific gastric lesions. By emphasizing the strengths and weaknesses of these imaging techniques, the review offers insights into optimizing their utilization for improved diagnosis, staging, and therapeutic management of neuroendocrine neoplasms.

Radiological-pathological correlation in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH): imaging and histopathology

AIM

To review histologically confirmed diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) cases and carry out a detailed pathological-radiological correlation to see if computed tomography (CT) can be used to confidently identify DIPNECH.

MATERIALS AND METHODS

Twenty-three histologically confirmed DIPNECH patients in the shared database of two NHS Trusts were reviewed. CT images were reviewed by two independent radiologists, each of them with >10 years of experience in thoracic imaging. All histological specimens were reviewed by a single pathologist with >25 years of experience. The diagnosis of DIPNECH was made according to the current World Health Organization (WHO) definition included in the WHO 2015 classification of pulmonary tumours. The results on histology were compared to the presence of nodules and air trapping on CT. Demographic information and, when available, molecular imaging studies and pulmonary function tests were also considered.

RESULTS

There are prototypal clinical and radiological findings reflecting the presence of underlying histological DIPNECH: middle-aged women with multiple small and scattered nodules due to the clustering and proliferation of neuroendocrine cells. At least one larger, dominant, lung nodule reflecting a carcinoid tumour is very common and mosaic attenuation/air trapping is seen approximately in 50% of cases in inspiratory scans. Airflow obstruction is rarely associated with histological bronchial or peribronchial fibrosis, which suggests other mechanisms must be involved in its development.

CONCLUSION

CT can be used to predict pathological DIPNECH in the appropriate clinical setting. It is important to consider DIPNECH to avoid overdiagnosis of more sinister conditions such as lung cancer or metastases.

Primary neuroendocrine carcinoma of cervical lymph node masquerading as non-Hodgkin lymphoma: A diagnostic challenge

ABSTRACT

A large extended family of tumors classified as neuroendocrine tumors most commonly occurs in the gastrointestinal tract and bronchus pulmonary tree. It is extremely unusual for a primary neuroendocrine tumor to present as a cervical lymph node mass at initial presentation. We discuss the rare case of a 55-year-old man who initially complained of a right neck mass that was misinterpreted as non-Hodgkin lymphoma on fine needle aspiration cytology. By integrating clinical findings, radiography, fine-needle aspiration cytology, histomorphology, and immunohistochemistry analysis, a definitive diagnosis of primary neuroendocrine carcinoma of the cervical lymph node was made. He received chemotherapy and decompressive radiation as treatment. Regarding the course of disease in the present case, the patients underwent a distant subcutaneous metastasis over the right anterior chest wall 10 months after the initial manifestation. The patient is still alive, albeit his general condition has gotten deteriorated, and he is getting regular follow-ups.

Masquerading as Pneumonia: A Lung Neuroendocrine Tumor Case Report

The presentation of recurrent pneumonia, particularly in the same lobe, should raise suspicion for possible neuroendocrine tumors of the lung within that respective lobe. Commonly, these types of tumors will have a gastrointestinal origin with a larger incidence of carcinoid syndrome, but they may also originate in the pancreas or lungs. This case illustrates the potential for a masked lung tumor in an otherwise young and healthy 31-year-old patient, with a short history of tobacco dependence and unremarkable family history, who presents with recurrent pneumonia and dyspnea. Although rare in itself, this case was even more unique due to the partial calcification of the neuroendocrine tumor mass along with causing a collapse in the entire right middle lobe.

Visual analysis of lung neuroendocrine tumors based on CiteSpace knowledge graph

Objective

The relevant literatures in the field of pulmonary neuroendocrine tumor were analyzed to understand the lineage, hot spots and development trends of research in this tumor.

Method

The Web of Science core collection was searched for English-language literature about neuroendocrine tumors of the lung published between 2000 and 2022. CiteSpace software was imported for visualization analysis of countries, institutions, co-cited authors and co-cited journals and sorting of high-frequency keywords, as well as co-cited references and keyword co-occurrence, clustering and bursting display.

Results

A total of 594 publications on neuroendocrine tumours of the lung were available, from 2000 to 2022, with an overall upward trend of annual publications in the literature. Authors or institutions from the United States, Italy, Japan and China were more active in this field, but there was little cooperation among the major countries. Co-cited references and keyword co-occurrence and cluster analysis showed that research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis and treatment was a current research hotspot. The keyword bursts suggested that therapeutic approaches might be a key focus of future research into the field for pulmonary neuroendocrine tumors.

Conclusion

Over these 20 years, research related to neuroendocrine tumors of the lung has increased in fervour, with research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis, and treatment being the main focus of research. Therapeutic treatments may be the future research trend in this field.

Malignant and Benign Tracheobronchial Neoplasms: Comprehensive Review with Radiologic, Bronchoscopic, and Pathologic Correlation

Tracheobronchial neoplasms are much less common than lung parenchymal neoplasms but can be associated with significant morbidity and mortality. They include a broad differential of both malignant and benign entities, extending far beyond more commonly known pathologic conditions such as squamous cell carcinoma and carcinoid tumor. Airway lesions may be incidental findings at imaging or manifest with symptoms related to airway narrowing or mucosal irritation, invasion of adjacent structures, or distant metastatic disease. While there is considerable overlap in clinical manifestation, imaging features, and bronchoscopic appearances, an awareness of potential distinguishing factors may help narrow the differential diagnosis. The authors review the epidemiology, imaging characteristics, typical anatomic distributions, bronchoscopic appearances, and histopathologic findings of a wide range of neoplastic entities involving the tracheobronchial tree. Malignant neoplasms discussed include squamous cell carcinoma, malignant salivary gland tumors (adenoid cystic carcinoma and mucoepidermoid carcinoma), carcinoid tumor, sarcomas, primary tracheobronchial lymphoma, and inflammatory myofibroblastic tumor. Benign neoplasms discussed include hamartoma, chondroma, lipoma, papilloma, amyloidoma, leiomyoma, neurogenic lesions, and benign salivary gland tumors (pleomorphic adenoma and mucous gland adenoma). Familiarity with the range of potential entities and any distinguishing features should prove valuable to thoracic radiologists, pulmonologists, and cardiothoracic surgeons when encountering the myriad of tracheobronchial neoplasms in clinical practice. Attention is paid to any features that may help render a more specific diagnosis before pathologic confirmation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

An Unusual Presentation of Occult Small-Cell Neuroendocrine Carcinoma as Acalculous Cholecystitis With Widespread Liver Metastasis

Small-cell neuroendocrine carcinoma, often classified as small-cell lung carcinoma (SCLC) type, is an aggressive neuroendocrine tumor with early metastatic potential that can lead to unexpected patient presentations. We report the case of a 69-year-old man who presented to the emergency department with worsening right upper abdominal pain, nausea, and vomiting for the past several days. The clinical picture and the workup, including the complete metabolic panel and complete blood count, were highly suggestive of acute cholecystitis with transaminitis and direct hyperbilirubinemia. The ultrasound and magnetic resonance cholangiopancreatography of the abdomen revealed a diffusely hyperdense and hypertrophic liver without evidence of choledocholithiasis. After initial resuscitation, the patient underwent laparoscopic cholecystectomy. Intraoperative findings were consistent with diffuse miliary liver metastatic disease of unknown etiology, rigid liver parenchyma, an extremely frail gallbladder wall, and mild ascites. A biopsy of the liver and cholecystectomy were performed. The final pathology revealed metastatic SCLC to the liver and widespread intravascular tumor emboli, causing diffuse ischemia of the entire gallbladder wall. The patient's postoperative course was marked by the development of foudroyant liver insufficiency and worsening severe type B lactic acidosis.

Washout-Computed Tomography Discriminates Pulmonary "Fat-poor" Hamartomas From Neuroendocrine Neoplasms: A Simple Method in the Radiomics Era

PURPOSE

Pulmonary hamartomas (HAs) and neuroendocrine neoplasms (NENs) are often impossible to discriminate using high-resolution computed tomography (CT) as they share morphologic features. This challenge makes differential diagnosis crucial as HAs are invariably benign, whereas NENs must be considered malignant, thus requiring them to be evaluated for surgical excision.Our aim was, therefore, to develop a simple method to discriminate between pulmonary "fat-poor" HAs and NENs using contrast-enhanced CT (CECT).

MATERIALS AND METHODS

Between September 2015 and December 2021, 95 patients with a histologically proven diagnosis of lung NENs (74) and HAs (21) and who underwent a preoperative CECT scan were initially identified through a review of our pathologic and radiologic databases. Among these, 55 cases (18 HAs and 37 NENs), which have been studied with biphasic CECT, were ultimately selected and reviewed by 3 radiologists with different levels of experience, analyzing their morphologic and enhancement features.The enhancement analysis was performed by placing a region of interest within the lesion in noncontrast (NCp), postcontrast (PCp, 55 to 65 s after intravenous contrast injection), and delayed phases (Dp, 180 to 300 s). A subgroup of 35 patients who underwent 18FDG-PET/CT was evaluated in a secondary analysis.

RESULTS

HU values were significantly different between NENs and HAs in the PCp ( P <0.001). NCp and Dp attenuation values did not show significant differences in the 2 groups. Differences in values of HUs in PCp and Dp allowed to discriminate between NENs and HAs.

CONCLUSION

Wash-out analysis, ΔHU (PCp-Dp), can perfectly discriminate pulmonary "fat-poor" HAs from NENs.

The Surgical Management of Lung Neuroendocrine Neoplasms

This review summarizes key recent developments relevant to the surgical management of lung neuroendocrine neoplasms (L-NENs), including typical and atypical carcinoids, large cell neuroendocrine carcinoma, and small cell lung carcinoma. This review includes recent insights into the classification, clinical presentation, diagnostic workup, treatment options, and follow-up. Highlighted topics include general principles of surgery in localized or locally advanced or metastatic L-NENs, lung-sparing surgery for small, peripheral typical carcinoids, adjuvant and systemic therapies for typical and atypical carcinoids, and surgery and adjuvant therapies for large cell neuroendocrine carcinoma and small cell lung carcinoma.

Reproducibility of CT radiomic features in lung neuroendocrine tumours (NETs) patients: analysis in a heterogeneous population

BACKGROUND

The aim is to find a correlation between texture features extracted from neuroendocrine (NET) lung cancer subtypes, both Ki-67 index and the presence of lymph-nodal mediastinal metastases detected while using different computer tomography (CT) scanners.

METHODS

Sixty patients with a confirmed pulmonary NET histological diagnosis, a known Ki-67 status and metastases, were included. After subdivision of primary lesions in baseline acquisition and venous phase, 107 radiomic features of first and higher orders were extracted. Spearman's correlation matrix with Ward's hierarchical clustering was applied to confirm the absence of bias due to the database heterogeneity. Nonparametric tests were conducted to identify statistically significant features in the distinction between patient groups (Ki-67 < 3-Group 1; 3 ≤ Ki-67 ≤ 20-Group 2; and Ki-67 > 20-Group 3, and presence of metastases).

RESULTS

No bias arising from sample heterogeneity was found. Regarding Ki-67 groups statistical tests, seven statistically significant features (p value < 0.05) were found in post-contrast enhanced CT; three in baseline acquisitions. In metastasis classes distinction, three features (first-order class) were statistically significant in post-contrast acquisitions and 15 features (second-order class) in baseline acquisitions, including the three features distinguishing between Ki-67 groups in baseline images (MCC, ClusterProminence and Strength).

CONCLUSIONS

Some radiomic features can be used as a valid and reproducible tool for predicting Ki-67 class and hence the subtype of lung NET in baseline and post-contrast enhanced CT images. In particular, in baseline examination three features can establish both tumour class and aggressiveness.

Carcinoid tumors outside the abdomen

Neuroendocrine tumors (NETs) are epithelial malignancies that can arise from multiple tissues. Gastrointestinal (GI) NETs are the most common; in this review of extra-abdominal carcinoid tumors, we focus our discussion on bronchial and thymic carcinoid tumors. Bronchial carcinoid tumors comprise a quarter of all NETs and less than 2% of all lung cancers. Thymic carcinoid tumors are extremely rare, accounting for 5% of thymic tumors. Both bronchial and thymic carcinoid tumors are histologically classified as either typical or atypical based on their mitotic rate (less than 2 or 2-10 mitoses per 10 high-powered fields (HPF), respectively). Both bronchial and thymic carcinoids can present with symptoms of obstruction and potentially carcinoid syndrome. The gold standard of management of bronchial and thymic carcinoid tumors is surgical resection. For patients with advanced disease, first-line systemic therapy is generally somatostatin analog monotherapy with octreotide or lanreotide. In patients with refractory disease, therapy generally involves peptide receptor radioligand therapy, everolimus, or cytotoxic chemotherapy. There are ongoing, prospective trials comparing the mainstays of systemic therapy for these patients, as well as ongoing evaluations of immune checkpoint inhibitors and multi-kinase inhibitors. Prognosis for both bronchial and thymic carcinoid tumors depends on histologic grade, local versus invasive disease, and extent of metastases. Herein we provide a summary of the pathophysiologic and clinical background, the current state of the field in diagnosis and management, and note of key ongoing prospective trials for patients with bronchial and thymic carcinoid tumors.

A rare localization of small-cell carcinoma in head and neck area: case report

Background

Small-cell carcinoma (SMCC) of hypopharynx is an extreme rare entity in the head and neck region. It is commonly arising from pulmonary in origin. We report a rare case of small-cell carcinoma of hypopharynx that caused upper airway obstruction in an elderly gentleman.

Case presentation

A 67-year-old man is presented to otorhinolaryngology clinic with a 4-month history of worsening shortness of breath and stridor. He was heavy tobacco smoker for 60 pack-years. Flexible nasopharyngolaryngoscopy revealed a large mass at the right pyriform fossa extending superiorly and obstructing the laryngeal inlet. He underwent tracheostomy, examination under general anesthesia with tissue biopsy. Histology from tissue biopsy revealed small-cell carcinoma. The positron emission tomography-CT showed exophytic mass from right pyriform sinus with regional and lung pleural metastasis as well. There was the absence of formal staging system for SMCC due to its limited and rare incidence. He was treated with combination of carboplatin and etoposide, similar to the regime for cell carcinoma of lung. The tumor regressed loco-regionally, and his pleural metastasis had shrunk to sub-centimeter in size.

Conclusions

To date, there is very limited data available on head and neck small cell carcinomas to guide treatment recommendations as well as staging system. Paucity of clinical data and outcome about this rare malignancy makes this report a valuable piece of experience to be shared together with existing literature.

Radiomics in pulmonary neuroendocrine tumours (NETs)

Objectives

The aim of this single-centre, observational, retrospective study is to find a correlation using Radiomics between the analysis of CT texture features of primary lesion of neuroendocrine (NET) lung cancer subtypes (typical and atypical carcinoids, large and small cell neuroendocrine carcinoma), Ki-67 index and the presence of lymph nodal mediastinal metastases.

Methods

Twenty-seven patients (11 males and 16 females, aged between 48 and 81 years old—average age of 70,4 years) with histological diagnosis of pulmonary NET with known Ki-67 status and metastases who have performed pre-treatment CT in our department were included. All examinations were performed with the same CT scan (Sensation 16-slice, Siemens). The study protocol was a baseline scan followed by 70 s delay acquisition after administration of intravenous contrast medium. After segmentation of primary lesions, quantitative texture parameters of first and higher orders were extracted. Statistics nonparametric tests and linear correlation tests were conducted to evaluate the relationship between different textural characteristics and tumour subtypes.

Results

Statistically significant (p < 0.05) differences were seen in post-contrast enhanced CT in multiple first and higher-order extracted parameters regarding the correlation with classes of Ki-67 index values. Statistical analysis for direct acquisitions was not significant. Concerning the correlation with the presence of metastases, one histogram feature (Skewness) and one feature included in the Gray-Level Co-occurrence Matrix (ClusterShade) were significant on contrast-enhanced CT only.

Conclusions

CT texture analysis may be used as a valid tool for predicting the subtype of lung NET and its aggressiveness.

Differential diagnostic value of 18F-FDG PET/CT in pulmonary carcinoids versus hamartomas

RATIONALE AND OBJECTIVE

To assess the possibility of differentiating pulmonary carcinoids from hamartomas and typical from atypical carcinoids by means of ¹⁸F-FDG PET/CT.

MATERIALS AND METHODS

We retrospectively reviewed 139 patients with pathologically proven pulmonary carcinoids and hamartomas who underwent ¹⁸F-FDG PET/CT before surgical resection. Receiver operating characteristics curves were calculated to determine the potential of SUVmax to discriminate between pulmonary carcinoids and hamartomas, typical and atypical carcinoids. The correlation between SUVmax and tumor size was analyzed by Spearman correlation analysis.

RESULTS

SUVmax was significantly higher in pulmonary carcinoids than in hamartomas (p<0.001), and also higher in atypical carcinoids than in typical carcinoids (p = 0.034). With a SUVmax of 2.0 as a cutoff, the sensitivity, specificity, positive predictive value, and negative predictive value for ¹⁸F-FDG PET/CT to differentiate pulmonary carcinoids from hamartomas were 85.3%, 82.9%, 61.7%, and 94.6%, respectively. The cutoff value of SUVmax for differentiating atypical carcinoids from typical carcinoids was 4.1. The area under the receiver operating characteristics curve of SUVmax was 0.900 for carcinoids and hamartomas, and 0.722 for typical and atypical carcinoids. SUVmax was correlated with maximum tumor size in pulmonary carcinoids (r = 0.658, p <0.001) and in pulmonary hamartomas (r = 0.672, p <0.001).

CONCLUSION

¹⁸F-FDG PET/CT might be a useful tool in the differential diagnosis of carcinoids and hamartomas, and can also distinguish atypical from typical carcinoids. This may facilitate improved selection of patients for surgical resection and radiological follow-up.

Endocrine and paracrine characteristics of neuroendocrine prostate cancer

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer.

Novel Non-Invasive Radiomic Signature on CT Scans Predicts Response to Platinum-Based Chemotherapy and Is Prognostic of Overall Survival in Small Cell Lung Cancer

BACKGROUND

Small cell lung cancer (SCLC) is an aggressive malignancy characterized by initial chemosensitivity followed by resistance and rapid progression. Presently, there are no predictive biomarkers that can accurately guide the use of systemic therapy in SCLC patients. This study explores the role of radiomic features from both within and around the tumor lesion on pretreatment CT scans to a) prognosticate overall survival (OS) and b) predict response to chemotherapy.

METHODS

One hundred fifty-three SCLC patients who had received chemotherapy were included. Lung tumors were contoured by an expert reader. The patients were divided randomly into approximately equally sized training (Str = 77) and test sets (Ste = 76). Textural descriptors were extracted from the nodule (intratumoral) and parenchymal regions surrounding the nodule (peritumoral). The clinical endpoints of this study were OS, progression-free survival (PFS), and best objective response to chemotherapy. Patients with complete or partial response were defined as "responders," and those with stable or progression of disease were defined as "non-responders." The radiomic risk score (RRS) was generated by using the least absolute shrinkage and selection operator (LASSO) with the Cox regression model. Patients were classified into the high-risk or low-risk groups based on the median of RRS. Association of the radiomic signature with OS was evaluated on Str and then tested on Ste. The features identified by LASSO were then used to train a linear discriminant analysis (LDA) classifier (MRad) to predict response to chemotherapy. A prognostic nomogram (NRad+Clin) was also developed on Str by combining clinical and prognostic radiomic features and validated on Ste. The Kaplan-Meier survival analysis and log-rank statistical tests were performed to assess the discriminative ability of the features. The discrimination performance of the NRad+Clin was assessed by Harrell's C-index. To estimate the clinical utility of the nomogram, decision curve analysis (DCA) was performed by calculating the net benefits for a range of threshold probabilities in predicting which high-risk patients should receive more aggressive treatment as compared with the low-risk patients.

RESULTS

A univariable Cox regression analysis indicated that RRS was significantly associated with OS in Str (HR: 1.53; 95% CI, [1.1-2.2; p = 0.021]; C-index = 0.72) and Ste (HR: 1.4, [1.1-1.82], p = 0.0127; C-index = 0.69). The RRS was also significantly associated with PFS in Str (HR: 1.89, [1.4-4.61], p = 0.047; C-index = 0.7) and Ste (HR: 1.641, [1.1-2.77], p = 0.04; C-index = 0.67). MRad was able to predict response to chemotherapy with an area under the receiver operating characteristic curve (AUC) of 0.76 ± 0.03 within Str and 0.72 within Ste. Predictors, including the RRS, gender, age, stage, and smoking status, were used in the prognostic nomogram. The discrimination ability of the NRad+Clin model on Str and Ste was C-index [95% CI]: 0.68 [0.66-0.71] and 0.67 [0.63-0.69], respectively. DCA indicated that the NRad+Clin model was clinically useful.

CONCLUSIONS

Radiomic features extracted within and around the lung tumor on CT images were both prognostic of OS and predictive of response to chemotherapy in SCLC patients.

Oat Cell Carcinoma Lung Presenting as Chest Wall Swelling

Chest wall swelling originating from lung is an uncommon phenomenon that makes its diagnosis a challenging task. We present a case where an 82-year-old man, a lifetime smoker, presented with a chest swelling. The origin of the swelling was an extension of a peripherally located lung malignancy diagnosed with the help of contrast-enhanced CT chest and confirmed as oat(or anaplastic) cell carcinoma on histology. After complete workup it was diagnosed as metastatic small cell carcinoma lung. Patient was managed with palliative chemoradiotherapy.

Added value of spectral parameters for the assessment of lymph node metastasis of lung cancer with dual-layer spectral detector computed tomography

Background

Lymph node (LN) metastasis is an important factor affecting the treatment of lung cancer. The purpose of this article was to investigate the benefits of dual-layer spectral detector computed tomography (SDCT) for the evaluation of metastatic LNs in lung cancer.

Methods

Data from 93 patients with lung cancer who underwent dual-phase enhanced scanning with SDCT were retrospectively analyzed. According to the pathological findings, 166 LNs were grouped as metastatic (n=80) or non-metastatic (n=86). LNs in station 4 (n=80) and station 7 (n=35) accounted for the majority of the LNs (approximately 69.23%). The short-axis diameter of the LN, arterial enhancement fraction (AEF), normalized iodine concentration (NIC), and the slope of the spectral Hounsfield unit curve (λ_HU) during the arterial phase (AP) and venous phase (VP) were measured. The Mann-Whitney U test was used to statistically compare these quantitative parameters. Receiver operating characteristic (ROC) curves were plotted to identify the cutoff values, and decision curve analysis (DCA) was performed to determine the net benefit of each parameter. The diagnostic performance, obtained by combining the short-axis diameter with each of the above parameters, was also studied.

Results

The short-axis LN diameter, AEF, NIC, and λ_HU during the AP and VP all showed significant differences between the metastatic and non-metastatic groups (P<0.05). Of the parameters, the AEF had the greatest diagnostic efficiency for metastatic LNs [area under the ROC curve (AUC)_AEF =0.885] with a threshold of 86.40%. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and 95% confidence interval were 90.00%, 89.53%, 88.89%, 90.59%, and 0.830-0.944, respectively. When the quantitative parameters were combined with the short-axis diameter, the AUCs of the parameters, except the AEF, were significantly improved (P<0.05).

Conclusions

The iodine quantitative parameters from SDCT, such as the AEF, demonstrated high diagnostic performances in the differentiation of metastatic and non-metastatic LNs.

Contribution of 18F-FDG PET/CT in the Differential Diagnosis of Pulmonary Hamartomas and Pulmonary Carcinoids

Objectives:

This study aimed to evaluate ¹⁸fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) findings in the differential diagnosis of pulmonary carcinoids and pulmonary hamartomas.

Methods:

¹⁸F-FDG PET/CT findings of 34 patients with pulmonary carcinoids (12 atypical, 22 typical) and 32 patients with pulmonary hamartomas were retrospectively evaluated. Both mean diameter and mean maximum standardized uptake value (SUV_max) of hamartomas and carcinoids were compared by Mann-Whitney U and Kruskall-Wallis H tests.

Results:

The mean longest diameter of atypical carcinoids (3.5±1.7 cm) was higher than that of hamartomas (2.1±1 cm) (p=0.038). No significant difference was found between the mean diameter of typical carcinoids and mean diameter of hamartomas (p=0.128). The mean SUV_max of atypical carcinoids (5.97±3.7) and typical carcinoids (4.22±1.7) were higher than those of hamartomas (1.65±0.9) (p=0.002 and p=0.003, respectively). There were collapse/consolidation in 55.8%, bronchiectasis or mucoid impaction in 47%, and air trapping in 14.7% in the peripheral parenchyma of the 34 carcinoids. Collapse/consolidation was detected in a patient with endobronchial hamartoma, and other finding was not found in the parenchyma around hamartomas.

Conclusion:

The ¹⁸F-FDG uptake of pulmonary carcinoids can vary from minimal to intense. ¹⁸F-FDG uptake can be seen in pulmonary hamartomas. However, the mean SUV_max of atypical carcinoids and typical carcinoids were higher compared to hamartomas. Pulmonary carcinoid must be suspected in cases with accompanying bronchial obstruction findings in the periphery of the mass.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: DIPNECH

PURPOSE OF REVIEW

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare premalignant condition. Over the past decade, there has been increased recognition and reporting of DIPNECH in the literature. Currently, our understanding is that DIPNECH has a predilection to nonsmoking females around their sixth decade of life. The patients usually present with chronic cough, dyspnea, and computed tomography (CT) showing multifocal pulmonary nodules with associated mosaic attenuation. The clinic history is largely driven by constrictive obliterative bronchiolitis, which typically has an indolent course with progressive respiratory decline and difficult to treat symptoms.

RECENT FINDINGS

DIPNECH has been found to be associated with carcinoid tumors. Recent data has found that symptomatic DIPNECH patients respond to somatostatin analog (SSA). SSAs provide improvement in symptoms and pulmonary function tests. According to small studies and case series SSAs can be used in conjunction with steroids and bronchodilators for the treatment of respiratory symptoms.

SUMMARY

DINPNECH is a premalignant condition that can transform into carcinoid tumors. Although the recent data suggest the potential efficacy of SSA, further studies are needed to validate such results in prospective fashion in addition to investigating other therapeutic agents.

Rare pulmonary tumors and carcinoma mimickers; experience from an interventional radiology unit with radiologic-pathologic correlation-A pictoral essay

BACKGROUND

Although imaging findings along with patients' clinical history may give clue for the etiology of a pulmonary lesion, the differentiation of benign pulmonary lesions from lung cancer could be challenging.

OBJECTIVE

The aim of this review article was to increase the awareness of the carcinoma mimicking lung lesions.

METHODS

This paper was designed to illustrate rare pulmonary tumors and carcinoma mimickers with emphasis on radiologic-pathologic correlation. Pitfalls encountered on CT images and also false positivity of PET-CT scans were also presented.

CONCLUSION

Several benign pulmonary lesions may grow in size on follow-up and some may show pathologic FDG (18F-fluorodeoxyglucose) uptake, which makes them indistinguishable from lung carcinoma by imaging. In addition, some slow-growing malignant lesions, such as carcinoid, may be false-negative on PET/CT scans.

Effectiveness of Thermal Ablation and Stereotactic Radiotherapy Based on Stage I Lung Cancer Histology

PURPOSE

To assess whether the effectiveness of thermal ablation (TA) and stereotactic body radiotherapy (SBRT) as initial treatments for stage I lung cancer varies depending on the histological subtype.

MATERIALS AND METHODS

The 2004-2016 National Cancer Database was queried for patients with American Joint Committee on Cancer stage I lung cancer treated with TA or SBRT. Patients <18 years, those treated with surgery or chemotherapy, or those with unknown survival and follow-up were excluded. TA and SBRT patients were 1:5 propensity score matched separately for each histological subtype to adjust for confounders. Overall survival (OS) was assessed using Cox models.

RESULTS

A total of 28,425 patients were included (SBRT, n = 27,478; TA, n = 947). TA was more likely to be used in Caucasian patients, those with more comorbidities and smaller neuroendocrine tumors (NETs) of the lower lobe, and those whose treatment had taken place in the northeastern United States. After propensity score matching, a cohort with 4,085 SBRT and 817 TA patients with balanced confounders was obtained. In this cohort, OS for TA and SBRT was comparable (hazard ratio = 1.07; 95% confidence interval,0.98-1.18; P = .13), although it varied by histological subtypes: higher OS for TA was observed in patients with non-small cell NETs (vs SBRT hazard ratio = 0.48; 95% confidence interval, 0.24-0.95; P = .04). No significant OS differences between TA and SBRT were noted for adenocarcinomas, squamous cell carcinomas, small cell carcinomas, and non-neuroendocrine large cell carcinomas (each, P > .1).

CONCLUSIONS

OS following TA and SBRT for stage I lung cancer is comparable for most histological subtypes, except that OS is longer after TA in non-small cell NETs.

Bronchial carcinoid tumor in the era of covid-19 pandemic: A case report

Introduction

Bronchial carcinoid tumors are rare, slow growing, malignant neuroendocrine tumors which arise from Enterochromaffin (Kulchitsky) cells. Early diagnosis is extremely important as the main stay of treatment is surgical excision.

Presentation of case

We present a rare case of bronchial typical carcinoid tumor in a 27-year-old male who presented with a complaint of intermittent dry cough of 2 weeks' duration associated with shortness of breath and low grade fever. He was initially misdiagnosed as covid-19 pneumonia and was admitted to covid-19 treatment center. Right lung bi-lobectomy with regional lymph node resection was done and he was discharged home in good condition.

Discussion

Majority of typical carcinoids are located in the central airways leading to bronchial obstruction with recurrent pneumonia, chest pain and wheezing. In the era of covid-19 pandemic, lung cancer patients are at higher risk of being affected by covid-19 and, early identification and differential diagnosis is extremely difficult in the absence of comprehensive evaluation and work up as the clinical and imaging findings of covid-19 may resemble lung cancer. Although hilar and mediastinal lymph nodes are the most common metastatic sites for typical carcinoids most lymphadenopathies are caused by a reactive inflammatory reaction.

Conclusion

Bronchial carcinoids are rare, malignant neuroendocrine tumors with complete surgical resection being the only curative management. During the Covid-19 pandemic crisis, diagnosing rare lung diseases like carcinoid tumor is real challenge especially in resource limited set up and needs high index of suspicion with meticulous diagnostic work up. The outcome of typical carcinoids with lymph node metastasis is excellent with complete resection.

Bronchial carcinoid with bronchocele masquerading as Scimitar syndrome on chest radiograph

Bronchial carcinoid tumors occur predominantly in the perihilar location and can be asymptomatic. They may present in early stages with only obstructive features such as mucus plugging of airways resulting in bronchocele formation. We report the case of a 44-year lady with no chest complaints, who underwent chest radiograph for a routine preanesthetic checkup. A vertically oriented, tubular, soft tissue density lesion was observed in the right lower lung, which mimicked a Scimitar vein. Scimitar syndrome is a congenital disorder in which an anomalous vein drains the middle and lower lobes of right lung and enters into the IVC most commonly. It may present asymptomatically in adults and on chest radiograph appears as a vertical tubular opacity paralleling the right cardiac border. However, CT angiography revealed the lung lesion to be a bronchocele, distal to a central intensely enhancing spherical mass, completely occluding the right lower lobe bronchus. This perihilar mass had been missed on the chest radiograph. Bronchoscopic biopsy revealed a carcinoid tumor. As the patient was asymptomatic, she refused surgery in the ongoing COVID-19 pandemic.

Bronchial carcinoid tumor: A case report

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Bronchial carcinoid tumor is exceedingly rare.

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Diagnosis of bronchial carcinoid is often delayed or even missed.

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Surgical excision is the main stay of treatment for bronchial carcinoid tumour.

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Typical carcinoid tumour has excellent prognosis.

Introduction

Bronchial carcinoid tumors are rare, slow growing, malignant neuroendocrine tumors and account for less than 2% of all lung tumors. Early diagnosis is extremely important as the main stay of treatment is surgical excision.

Presentation of case

We present a rare case of bronchial typical carcinoid tumor in a 22-year-old female who presented with a complaint of intermittent productive cough with bloody sputum of 3 weeks’ duration associated with wheezing, low grade intermittent fever and loss of appetite. She was being treated as bronchial asthma for 10 years prior to her current presentation. Right lung bi-lobectomy with regional lymph node resection was done and she was discharged home in good condition.

Discussion

Majority of typical carcinoids are located in the central airways leading to bronchial obstruction with recurrent pneumonia, chest pain, wheezing and hemoptysis. Due to such nonspecific presentation most patients are misdiagnosed or diagnosed late. Both typical and atypical Carcinoids have similar radiologic features and definitive diagnosis relies on bronchoscopic tissue biopsy. Although hilar and mediastinal lymph nodes are the most common metastatic sites for typical carcinoids most lymphadenopathies are caused by a reactive inflammatory reaction.

Conclusion

Bronchial carcinoids are rare, malignant neuroendocrine tumors with complete surgical resection being the only curative management. Thus patients with recurrent respiratory symptoms despite optimum medical treatment should be thoroughly investigated for accurate and early diagnosis The outcome of typical carcinoids with lymph node metastasis is excellent with complete resection but close follow up is mandatory when dealing with larger tumors.

Computed tomography-based differentiation of primary pulmonary lymphoepithelioma-like carcinoma and small-cell lung cancer

BACKGROUND

Primary pulmonary lymphoepithelioma-like carcinoma (LELC) is a rare subtype of lung cancer. Both small-cell lung cancer (SCLC) and LELC often manifest as a centrally located tumor with lymphadenopathy. This retrospective study investigated and compared the initial computed tomography (CT) features and subsequent survival outcomes of LELC and SCLC.

METHODS

A total of 50 patients with a confirmed diagnosis of LELC were enrolled and matched at a ratio of 1:1 with patients with SCLC according to the tumor stage. Utilizing a consensus approach, two radiologists reviewed pretreatment CT images. Survival outcomes were analyzed.

RESULTS

Well-defined tumors were significantly more common in the LELC group (LELC: 42% vs SCLC: 24%, p = 0.005). Based on the comparisons of the primary tumor with the muscles, LELC tumors exhibited a significantly higher percentage of attenuation on contrast-enhanced CT scans (21.6% ± 29% vs -14.2% ± 37%, p < 0.001). The prevalence of vascular or bronchial encasement (18% vs 40%, p = 0.028), background emphysematous changes (10% vs 60%, p < 0.001), and tumors located in upper lobes (18% vs 64%, p < 0.001) was significantly lower in the LELC group. Female gender (70% vs 12%, p < 0.001), younger age (57.6 ± 12.0 years vs 68.0 ± 11.0 years, p < 0.001), and without a history of smoking (16% vs 88%, p < 0.001) were factors more commonly found in the LELC group. The patients with LELC had a better prognosis with significantly longer median survival than did the patients with SCLC (23.4 months vs 17.3 months, p = 0.01).

CONCLUSION

Because SCLC demonstrated a more aggressive disease progression, differentiating LELC from SCLC is crucial. In Epstein-Barr virus-endemic areas, the diagnosis of LELC should be considered when approaching a patient with the above-mentioned CT and clinical features.

Multimodality Imaging of Neuroendocrine Tumors

Neuroendocrine tumors are rare solid tumors with an estimated 12,000 people in the United States diagnosed each year. Neuroendocrine tumors can occur in any part of the body. There is a wide spectrum of disease, ranging from slow-growing and indolent tumors found incidentally to highly aggressive malignancies with a poor prognosis. Knowledge of neuroendocrine tumor pathology is essential in the diagnostic workup of these patients. This article focuses on the evaluation, detection, and staging of common neuroendocrine tumors with multiple imaging modalities; the information gained with a multimodality approach is often complementary and leads to image-guided treatment decision making.

Current Applications for Nuclear Medicine Imaging in Pulmonary Disease

Purpose of Review

The main goal of the article is to familiarize the reader with commonly and uncommonly used nuclear medicine procedures that can significantly contribute to improved patient care. The article presents examples of specific modality utilization in the chest including assessment of lung ventilation and perfusion, imaging options for broad range of infectious and inflammatory processes, and selected aspects of oncologic imaging. In addition, rapidly developing new techniques utilizing molecular imaging are discussed.

Recent Findings

The article describes nuclear medicine imaging modalities including gamma camera, SPECT, PET, and hybrid imaging (SPECT/CT, PET/CT, and PET/MR) in the context of established and emerging clinical applications. Areas of potential future development in nuclear medicine are discussed with emphasis on molecular imaging and implementation of new targeted tracers used in diagnostics and therapeutics (theranostics).

Summary

Nuclear medicine and molecular imaging provide many unique and novel options for the diagnosis and treatment of pulmonary diseases. This article reviews current applications for nuclear medicine and molecular imaging and selected future applications for radiopharmaceuticals and targeted molecular imaging techniques.

An Assessment of Circulating Chromogranin A as a Biomarker of Bronchopulmonary Neuroendocrine Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND

Management of bronchopulmonary neuroendocrine neoplasia (NEN; pulmonary carcinoids [PCs], small-cell lung cancer [SCLC], and large cell neuroendocrine carcinoma) is hampered by the paucity of biomarkers. Chromogranin A (CgA), the default neuroendocrine tumor biomarker, has undergone wide assessment in gastroenteropancreatic neuroendocrine tumors.

OBJECTIVES

To evaluate CgA in lung NEN, define its clinical utility as a biomarker, assess its diagnostic, prognostic, and predictive efficacy, as well as its accuracy in the identification of disease recurrence.

METHODS

A systematic review of PubMed was undertaken using the preferred reporting items for systematic reviews and meta-analyses guidelines. No language restrictions were applied. Overall, 33 original scientific papers and 3 case reports, which met inclusion criteria, were included in qualitative analysis, and meta-analysis thereafter. All studies, except 2, were retrospective. Meta-analysis statistical assessment by generic inverse variance methodology.

RESULTS

Ten different CgA assay types were reported, without consistency in the upper limit of normal (ULN). For PCs (n = 16 studies; median patient inclusion 21 [range 1-200, total: 591 patients]), the CgA diagnostic sensitivity was 34.5 ± 2.7% with a specificity of 93.8 ± 4.7. CgA metrics were not available separately for typical or atypical carcinoids. CgA >100 ng/mL (2.7 × ULN) and >600 ng/mL (ULN unspecified) were anecdotally prognostic for overall survival (n = 2 retrospective studies). No evidence was presented for predicting treatment response or identifying post-surgery residual disease. For SCLC (n = 19 studies; median patient inclusion 23 [range 5-251, total: 1,241 patients]), the mean diagnostic sensitivity was 59.9 ± 6.8% and specificity 79.4 ± 3.1. Extensive disease typically exhibited higher CgA levels (diagnostic accuracy: 61 ± 2.5%). An elevated CgA was prognostic for overall survival (n = 4 retrospective studies). No prospective studies evaluating predictive benefit or prognostic utility were identified.

CONCLUSION

The available data are scarce. An assessment of all published data showed that CgA exhibits major limitations as an effective and accurate biomarker for either PC or SCLC. Its utility especially for localized PC/limited SCLC (when surgery is potentially curative), is limited. The clinical value of CgA remains to be determined. This requires validated, well-constructed, multicenter, prospective, randomized studies. An assessment of all published data indicates that CgA does not exhibit the minimum required metrics to function as a clinically useful biomarker for lung NENs.

Blood Chromogranin A Is Not Effective as a Biomarker for Diagnosis or Management of Bronchopulmonary Neuroendocrine Tumors/Neoplasms

BACKGROUND

Identification of circulating tumor markers for clinical management in bronchopulmonary (BP) neuroendocrine tumors/neoplasms (NET/NEN) is of considerable clinical interest. Chromogranin A (CgA), a "universal" NET biomarker, is considered controversial as a circulating biomarker of BPNEN.

AIM

Assess utility of CgA in the diagnosis and management of BPNEN in a multicentric study.

MATERIAL AND METHODS

CgA diagnostic metrics were assessed in lung NET/NENs (n = 200) and controls (n = 140), randomly assigned to a Training and Test set (100 BPC and 70 controls in each). Assay specificity was evaluated in neoplastic lung disease (n = 137) and nonneoplastic lung disease (n = 77). CgA efficacy in predicting clinical status was evaluated in the combined set of 200 NET/NENs. CgA levels in bronchopulmonary neuroendocrine tumor (BPNET) subtypes (atypical [AC] vs. typical [TC]) and grade was examined. The clinical utility of an alteration of CgA levels (±25%) was evaluated in a subset of 49 BPNET over 12 months. CgA measurement was by NEOLISATM kit (EuroDiagnostica).

RESULTS

Sensitivity and specificity in the training set were 41/98%, respectively. Test set data were 42/87%. Training set area under receiver operator characteristic analysis differentiated BPC from control area under the curve (AUC) 0.61 ± 0.05 p = 0.015. Test set the data were AUC 0.58 ± 0.05, p = 0.076. In the combined set (n = 200), 67% BPNET/NEN (n = 134) had normal CgA levels. CgA levels did not distinguish histological subtypes (TC vs. AC, AUC 0.56 ± 0.04, p = 0.21), grade (p = 0.45-0.72), or progressive from stable disease (AUC 0.53 ± 0.05 p = 0.47). There was no correlation of CgA with Ki-67 index (Pearson r = 0.143, p = 0.14). For nonneoplastic diseases (chronic obstructive pulmonary disorder and idiopathic pulmonary fibrosis), CgA was elevated in 26-37%. For neoplastic disease (NSCLC, squamous cell carcinoma), CgA was elevated in 11-16%. The neuroendocrine SCLC also exhibited elevated CgA (50%). Elevated CgA was not useful for differentiating BPNET/NEN from these other pathologies. Monitoring BPNET/NEN over a 12-month period identified neither CgA levels per se nor changes in CgA were reflective of somatostatin analog treatment outcome/efficacy or the natural history of the disease (progression).

CONCLUSIONS

Blood CgA levels are not clinically useful as a biomarker for lung BPNET/NEN. The low specificity and elevations in both nonneoplastic as well as other common neoplastic lung diseases identified limited clinical utility for this biomarker.

A case of pseudocystic liver metastases from an atypical lung carcinoid tumor

Metastatic neuroendocrine tumors of the liver typically appear as solid, hypervascular masses on imaging. Pseudocysts mimicking simple cysts are extremely rare. A 42-year-old Japanese woman was referred with a single pulmonary mass in the left lower lobe. No metastatic lesion was detected and no occupying lesion in the liver was observed. The lung tumor was diagnosed as an atypical carcinoid. Postoperative investigation revealed new hepatic simple cysts in the liver, which increased in size over time and changed into hemorrhagic cysts. Fluorodeoxyglucose positron emission tomography and somatostatin receptor scintigraphy using 111In-octreotide demonstrated no accumulation in the liver. Our patient did not have symptoms consistent with carcinoid syndrome. The patient underwent partial resection of the cystic lesions of the liver. Gross examination of the tumors demonstrated thin-wall cavitated lesions with hemorrhage which were metastases from the atypical carcinoid of the lung. When a growing cystic lesion with intracystic hemorrhage is found in the liver of a patient with a history of carcinoid tumors, pseudocysts caused by degeneration of a carcinoid metastasis should be considered as a differential diagnosis.

Small cell lung cancer mimicking lymphoma in CT and 68Ga-DOTA-NOC PET/CT: A case report

RATIONALE

Small cell lung cancer accounts for 15-20% of all lung cancers and is the most common pulmonary neuroendocrine neoplasm. Most small cell lung cancers arise from lobar or main bronchi, the most common manifestations of small cell lung cancer is a large mass centrally located within the lung parenchyma or a mediastinal mass involving the hilus. Small cell lung cancer is easily ignored by clinicians without lung parenchyma and hilus involvement. Here, we report a case of small cell lung cancer, which was misdiagnosed as the lymphoma in contrast enhanced CT and Ga-DOTA-NOC PET/CT imagings.

PATIENT CONCERNS

A 49-year-old male with chief complaint of discontinuous cough for 1 month.

DIAGNOSES

Small cell lung cancer.

INTERVENTIONS

Radiotherapy and chemotherapy were given thereafter.

OUTCOMES

The case had multiple enlarged lymph nodes due to tumor progression.

LESSONS

Small cell lung cancer is a malignant and progressive disease, and easy to be ignored in clinical. The case of small cell lung cancer without parenchyma and hilus involvement has never been reported before. Here, we report it and hope it provides a differential diagnosis for clinicians in the following similar cases.

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.

Nothing But NET: A Review of Neuroendocrine Tumors and Carcinomas

This review covers the diverse topic of neuroendocrine neoplasms (NENs), a relatively rare and heterogeneous tumor type, comprising ~2% of all malignancies, with a prevalence of <200,000 in the United States, which makes it an orphan disease (Basu et al., 2010).1 For functional purposes, NENs are divided into two groups on the basis of clinical behavior, histology, and proliferation rate: well differentiated (low grade to intermediate grade) neuroendocrine tumors and poorly differentiated (high grade) neuroendocrine carcinoma (Bosman et al., 2010)2; this histological categorization/dichotomization is highly clinically relevant with respect to impact on treatment and prognosis even though it is not absolute since a subset of tumors with a low-grade appearance behaves similarly to high-grade lesions. Given the relative dearth of evidenced-based literature about this orphan disease as a whole (Modlin et al., 2008),3 since the focus of most articles is on particular anatomic subtypes of NENs (i.e., gastroenteropancreatic or pulmonary), the purpose of this review is to summarize the presentation, pathophysiology, staging, current standard of care treatments, and active areas of current research.

Multimodality Imaging Findings in Carcinoid Tumors: A Head-to-Toe Spectrum

Carcinoid tumors are a rare biologically heterogeneous group of neuroendocrine tumors with a spectrum ranging from benign indolent to aggressive metastatic tumors. They belong to the category of amine precursor uptake and decarboxylase tumors, or apudomas. The most common sites for primary locations are the gastrointestinal and respiratory tracts; however, any organ can be involved. The clinical presentation depends on location, aggressiveness, production of biologically active amines and peptides, paraneoplastic syndromes, and tendency for metastasis. Their reported age-adjusted incidence has increased in recent years, partly due to improved detection at radiologic imaging and endoscopy. Not a ll neuroendocrine cell tumors are carcinoids. Numerous systems have been proposed regarding their nomenclature and classification. Cross-sectional and functional imaging plays an important role in diagnosis, lesion characterization, and staging. Awareness of nomenclature, classification, common sites of involvement, and imaging presentation are pivotal for making the diagnosis. Knowledge of the diverse clinical, pathologic, and radiologic spectrum of carcinoid tumors involving various organs of the body is important for diagnosis and patient management. ^©RSNA, 2017.

Imaging of Neuroendocrine Tumors: Indications, Interpretations, Limits, and Pitfalls

Imaging is critical in the diagnosis, prognosis, and management of neuroendocrine tumors (NETs). NETs share common imaging features, but each type exhibits unique features. Computed tomography scans or MRI of the abdomen is used to assess tumor burden routinely. Functional imaging with octreotide scan or gallium-68 somatostatin analog PET is used selectively to confirm diagnosis and guide therapy. Clinicians and radiologists should be familiar with the indications and interpretations of imaging modalities. Novel functional imaging modalities likely will be developed to detect small NETs, predict prognosis, guide therapeutic choices, and design novel therapies.

Primary lung carcinoid metastatic to the breast

Lung carcinoid tumors account for approximately 2% of lung cancers, with 10% of the tumors represented by the atypical type. While atypical carcinoids are metastatic to intrathoracic lymph nodes in approximately half of the cases on the initial presentation, distant metastases are seen in only 20% of the patients and are found most frequently in bones, liver, adrenal glands, and brain. We present a case of an unusual metastatic disease to the breast in 51-year-old female who developed a new breast mass 2 years after left lower lobectomy due to atypical carcinoid tumor. Atypical pulmonary carcinoid metastases to the breast are exceptionally uncommon, yet they are important considerations for appropriate management, especially with an anamnesis of this neoplasm.

[Localised bronchiectasis revealing carcinoid tumor]

Nous rapportons l'observation d'une patiente âgée de 32 ans, qui a présenté un syndrome bronchique purulent récidivant depuis 05 ans. Le bilan radiologique a montré des clartés finement cerclés au niveau basithoracique gauche en rapport avec des dilatations de bronche localisée au niveau du lobe inferieur gauche, de type cylindrique. La bronchoscopie souple a montré une tumeur rougeâtre à surface lisse obstruant l'entrée de la pyramide basale gauche. La patiente a bénéficié d'une lobectomie inferieure gauche plus curage ganglionnaire médiastinal. Les résultats de l'étude anatomopathologique de la pièce opératoire sont en faveur d'une tumeur carcinoïde typique. La suite post-opératoire était sans complication et l'évolution clinique et radiologique est bonne.

Well-differentiated bronchial neuroendocrine tumors: Clinical management and outcomes in 105 patients

INTRODUCTION

Bronchial neuroendocrine tumors (NETs) are rare tumors representing approximately 20%-30% of all neuroendocrine tumors and 2%-3% of all adult lung cancers. Here, they present a large case series of well-differentiated bronchial NETs with the aim of investigating the behavior of these tumors and long-term outcomes.

METHODS

A retrospective review was performed of 105 patients with bronchial NETs managed in a tertiary referral center in the period between January 1998 and January 2012.

RESULTS

Bronchial NETs are commoner in females and the commonest presenting symptoms were cough (13.9%) and dyspnoea (11.6%). Octreoscan^TM and Gallium-68 DOTATATE PET were found to have similar diagnostic sensitivity and FDG PET was more sensitive for higher-grade tumors. Over a median follow-up period of 35.5 months mortality rate was 5.7%. The 5-year survival was 76% and the 10-year survival was 62%. Female patients survived longer but this difference was not statistically significant (P = .59). Older age greater than 50 years (P = .027), higher levels of Chromogranin A (CgA) (P = .034), first-line treatment with surgery (P = .005), ki67 over 10% (P = .037), and tumor stage (P = .036) but not tumor grade (P = .22), were significantly associated with survival.

DISCUSSION

Several factors have been identified which are independently associated with survival including CgA levels greater than 100 pmol/L, tumor stage, age greater than 50, ki67 over 10% and having surgery as first-line treatment. There was no difference in survival between typical and atypical carcinoids.

CT findings of small cell lung carcinoma: Can recognizable features be found?

The purpose of this study was to clarify the recognizable computed tomography (CT) features of small cell lung carcinoma (SCLC).Contrast enhanced CT scans were reviewed retrospectively for mass location, mediastinal extension, and other concomitant findings in 142 patients with pathologically proven SCLC. SCLC was classified into hilar mass only (type I), hilar mass with ipsilateral mediastinal extension (type II), hilar mass with bilateral mediastinal extension (type III), and peripheral mass (type IV). When mediastinal lymphadenopathy (m-LAP) was indistinguishable from a hilar mass, we defined it as a mediastinal conglomerate mass (m-CM). Type IIa or IIIa had ipsilateral or bilateral m-LAP and type IIb, IIIb or IIIc had ipsilateral or bilateral m-CM.Type I (n = 8, 5.6%), type II (n = 58, 40.8%), type III (n = 55, 38.8%), and type IV (n = 21, 14.8%) were manifested. The combination of a hilar mass and m-CM was found in 68 patients (47.9%). Type IV masses showed lobulation in 11, microlobulation in 4, both lobulated and irregular margins in 4, and spiculation in 2. A total of 120 patients (84.5%) had a bronchial stenosis/obstruction; single (n = 52) and 2 or more (n = 68). Ninety-five patients (67.0%) had vascular invasion including main/lobar pulmonary artery and superior vena cava, and 55 (38.7%) had pleural effusion and/or pleural nodules. Concomitant parenchymal findings (n = 92, 64.8%) were noted: contiguous consolidation/nodule (n = 45), hematogeneous spread (n = 32), lymphangitic spread (n = 21), obstructive pneumonia (n = 22), and obstructive atelectasis (n = 14).In conclusion, the recognizable CT features of SCLC were a hilar mass with m-CM. Most of the hilar masses showed 2 or more bronchial stenoses/obstructions. Most cases of peripheral SCLC manifested as a lobulated mass rather than a spiculated mass. Vascular invasion and concomitant parenchymal findings were observed commonly.

Cardiothoracic manifestations of neuroendocrine tumours

Cardiothoracic neuroendocrine tumour (NET) manifestations encompass a vast disease spectrum. Pulmonary neuroendocrine tumours represent a range of tumour grade and differentiation characteristics from pre-malignant diffuse neuroendocrine cell hyperplasia, well-differentiated, low-grade carcinoid tumours with excellent outcomes, through to high-grade small-cell lung carcinoma and large-cell neuroendocrine carcinoma with poor prognoses. Rarer thymic NETs represent a similarly wide neoplastic spectrum. Cardiac carcinoid is a paraneoplastic manifestation of the carcinoid syndrome and often the cause of mortality in NETs with hepatic metastases. Cardiothoracic NET manifestations are reviewed herein from a radiologists' perspective, discussing the diverse clinical presentations, spectrum of neoplastic and paraneoplastic manifestations, imaging features and treatment options.