Current and emerging strategies for the management of advanced/metastatic lung neuroendocrine tumors

Pulmonary neuroendocrine tumors represent a spectrum of disease ranging from typical carcinoid tumors to small cell lung cancers. The incidence of low-grade pulmonary NETs has been increasing, leading to improved awareness and the need for more treatment options for this rare cancer. Somatostatin analogs continue to be the backbone of therapy and may be followed or accompanied by targeted therapy, chemotherapy, and immune therapy. The recent addition of peptide receptor radionuclide therapy (PRRT) to the treatment armamentarium of NETs has led to the development of targeted alpha therapy to overcome PRRT resistance and minimize off-target adverse effects. Herein, we aim to highlight current treatment options for patients with advanced low grade pulmonary NETs along with emerging therapies, sequencing of therapies, upcoming clinical trials, and the importance of a multidisciplinary team to improve patient outcomes.

Prognostic thresholds of fluorine-18 fluorodeoxyglucose-positron emission tomography mean and maximum standardized uptake values for survival and nodal involvement in lung neuroendocrine neoplasms

OBJECTIVES

The mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose-positron emission tomography are prognostic biomarkers for survival and nodal involvement in non-small-cell lung cancer but their prognostic value in lung neuroendocrine neoplasms (NENs) remains unexplored. In this study, we aimed to examine whether they are also prognostic biomarkers for survival and nodal involvement in lung NENs.

METHODS

We retrospectively studied patients with typical carcinoid, atypical carcinoid or large cell neuroendocrine carcinoma who had been radically resected at our institution between 2008 and 2020. We measured SUVmean and SUVmax on all primary tumours and lymph nodes that were clinically and/or pathologically involved. We dichotomized the patients into groups of high or low SUVmean and SUVmax of the primary tumour using time-dependent receiver operating characteristic curves and compared their overall survival using Kaplan-Meier curves and Cox models. Lastly, we predicted the patients' pathological nodal status with SUVmean and SUVmax of the lymph nodes using binomial logistic models.

RESULTS

The study included 245 patients. Patients died earlier if their SUVmean of the primary tumour exceeded 3.9 [hazard ratio 1.97, 95% confidence interval (CI) 1.27-3.04, P = 0.002] or SUVmax exceeded 5.3 (hazard ratio 1.85, 95% CI 1.20-2.87, P = 0.006). Likewise, patients had a higher risk of pathological nodal involvement if their SUVmean of the lymph nodes exceeded 3.3 (odds ratio 10.00, 95% CI 2.59-51.01, P = 0.002) or SUVmax exceeded 4.2 (odds ratio 4.00, 95% CI 1.20-14.65, P = 0.028).

CONCLUSIONS

The fluorine-18 fluorodeoxyglucose-positron emission tomography SUVmean and SUVmax are strong prognostic biomarkers for survival and nodal involvement in lung NENs and could be important guides for making treatment decisions.

The First Case Report of Effective Treatment With Sotorasib for Metastatic Atypical Lung Carcinoid Harboring KRAS G12C Mutation and Aggressive Disseminated Lung Metastasis: A Case Report

Pulmonary neuroendocrine tumors are rare, accounting for approximately 1% to 2% of lung cancers. Atypical carcinoids account for approximately 10% of pulmonary neuroendocrine tumors and are categorized as moderately malignant. Treatment options for advanced-stage atypical carcinoids include everolimus, cytotoxic anticancer agents, and peptide receptor radionuclide therapy. In this report, we present the first case of KRAS G12C mutation-positive atypical carcinoid that was successfully treated with sotorasib. Therapeutically important mutations observed in non-small cell lung cancer are seldom found in atypical carcinoid tumors. Nonetheless, it is worthwhile to search for genetic mutations in atypical carcinoid tumors, considering the potential for molecular targeted therapy to be effective in their treatment as well.

Volume Doubling Time of Pulmonary Carcinoid Tumors Measured by Computed Tomography

INTRODUCTION

Pulmonary carcinoid tumor (PCT) is a rare neuroendocrine lung neoplasm comprising approximately 2% of lung cancer diagnoses. It is classified as either localized low-grade (typical) or intermediate-grade (atypical) subtypes. PCT is known clinically to be a slow-growing cancer, however few studies have established its true growth rate when followed over time by computed tomography (CT). Therefore, we sought to determine the volume doubling time for PCTs as visualized on CT imaging.

MATERIALS AND METHODS

We conducted a retrospective analysis of all PCTs treated at our institution between 2006 and 2020. Nodule dimensions were measured using a Picture Archiving and Communication System or retrieved from radiology reports. Volume doubling time was calculated using the Schwartz formula for PCTs followed by successive CT scans during radiographic surveillance. Consistent with Fleischner Society guidelines, tumors were considered to have demonstrated definitive growth by CT only when the interval change in tumor diameter was greater than or equal to 2 mm.

RESULTS

The median volume doubling time of 13 typical PCTs was 977 days, or 2.7 years. Five atypical PCTs were followed longitudinally, with a median doubling time of 327 days, or 0.9 years.

CONCLUSIONS

Typical pulmonary carcinoid features a remarkably slow growth rate as compared to more common lung cancers. Our analysis of atypical pulmonary carcinoid included too few cases to offer definitive conclusions. It is conceivable that clinicians following current nodule surveillance guidelines may mistake incidentally detected typical carcinoids for benign non-growing lesions when followed for less than 2 years in low-risk patients.

Value of [68Ga]Ga-somatostatin receptor PET/CT in the grading of pulmonary neuroendocrine (carcinoid) tumours and the detection of disseminated disease: single-centre pathology-based analysis and review of the literature

BACKGROUND

Although most guidelines suggest performing a positron emission tomography/computed tomography (PET/CT) with somatostatin receptor (SSTR) ligands for staging of pulmonary carcinoid tumours (PC), only a limited number of studies have evaluated the role of this imaging tool in this specific patient population. The preoperative differentiation between typical carcinoid (TC) and atypical carcinoid (AC) and the extent of dissemination (N/M status) are crucial factors for treatment allocation and prognosis of these patients. Therefore, we performed a pathology-based retrospective analysis of the value of SSTR PET/CT in tumour grading and detection of nodal and metastatic involvement of PC and compared this with the previous literature and with [¹⁸F]FDG PET/CT in a subgroup of patients.

METHODS

SSTR PET/CT scans performed between January 2007 and May 2020 in the context of PC were included. If available, [¹⁸F]FDG PET/CT images were also evaluated. The maximum standardized uptake (SUV_max) values of the primary tumour, of the pathologically examined hilar and mediastinal lymph node stations, as well as of the distant metastases, were recorded. Tumoural SUV_max values were related to the tumour type (TC versus AC) for both SSTR and [¹⁸F]FDG PET/CT in diagnosing and differentiating both tumour types. Nodal SUV_max values were compared to the pathological status (N⁺ versus N^-) to evaluate the diagnostic accuracy of SSTR PET/CT in detecting lymph node involvement. Finally, a mixed model analysis of all pathologically proven distant metastatic lesions was performed.

RESULTS

A total of 86 SSTR PET/CT scans performed in 86 patients with PC were retrospectively analysed. [¹⁸F]FDG PET/CT was available in 46 patients. Analysis of the SUV_max values in the primary tumour showed significantly higher SSTR uptake in TC compared with AC (median SUV_max 18.4 vs 3.8; p = 0.003) and significantly higher [¹⁸F]FDG uptake in AC compared to TC (median SUV_max 5.4 vs 3.5; p = 0.038). Receiver operating characteristic (ROC) curve analysis resulted in an area under the curve (AUC) of 0.78 for the detection of TC on SSTR PET/CT and of 0.73 for the detection of AC on [¹⁸F]FDG PET/CT. A total of 267 pathologically evaluated hilar and mediastinal lymph node stations were analysed. ROC analysis of paired SSTR/[¹⁸F]FDG SUV_max values for the detection of metastasis of TC in 83 lymph node stations revealed an AUC of 0.91 for SSTR PET/CT and of 0.74 for [¹⁸F]FDG PET/CT (difference 0.17; 95% confidence interval - 0.03 to 0.38; p = 0.10). In a sub-cohort of 10 patients with 12 distant lesions that were pathologically examined due to a suspicious aspect on SSTR PET/CT, a positive predictive value (PPV) of 100% was observed.

CONCLUSION

Our findings confirm the higher SSTR ligand uptake in TC compared to AC and vice versa for [¹⁸F]FDG uptake. More importantly, we found a good diagnostic performance of SSTR PET/CT for the detection of hilar and mediastinal lymph node metastases of TC. Finally, a PPV of 100% for SSTR PET/CT was found in a small sub-cohort of patients with pathologically investigated distant metastatic lesions. Taken together, SSTR PET/CT has a very high diagnostic value in the TNM assessment of pulmonary carcinoids, particularly in TC, which underscores its position in European guidelines.

Clinic and genetic similarity assessments of atypical carcinoid, neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic count and large cell neuroendocrine carcinoma

Background

Pulmonary neuroendocrine neoplasms can be divided into typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell (lung) carcinoma. According to the World Health Organization, these four neoplasms have different characteristics and morphological traits, mitotic counts, and necrotic status. Importantly, “a grey-zone” neoplasm with an atypical carcinoid-like morphology, where the mitotic rate exceeds the criterion of 10 mitoses per 2 mm², have still not been well classified. In clinical practice, the most controversial area is the limit of 11 mitoses to distinguish between atypical carcinoids and large cell neuroendocrine carcinomas.

Methods

Basic and clinical information was obtained from patient medical records. A series of grey-zone patients (n = 8) were selected for exploring their clinicopathological features. In addition, patients with atypical carcinoids (n = 9) and classical large cell neuroendocrine carcinomas (n = 14) were also included to compare their similarity to these neoplasms with respect to tumour morphology and immunohistochemical staining.

Results

We found that these grey-zone tumour sizes varied and affected mainly middle-aged and older men who smoked. Furthermore, similar gene mutations were found in the grey-zone neoplasms and large cell neuroendocrine carcinomas, for the mutated genes of these two are mainly involved in PI3K-Akt signal pathways and Pathways in cancer, including a biallelic alteration of TP53/RB1 and KEAP1.

Conclusions

Our findings indicate that neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic counts is more similar to large cell neuroendocrine carcinoma than atypical carcinoid. Furthermore, this study may help improve diagnosing these special cases in clinical practice to avoid misdiagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09391-w.

Lung Neuroendocrine Tumors: How Does Molecular Profiling Help?

PURPOSE OF REVIEW

Lung neuroendocrine tumors (NETs)-typical carcinoids and atypical carcinoids-have unique molecular alterations that are distinct from neuroendocrine carcinomas of the lung and non-small cell lung cancers. Here, we review the role of molecular profiling in the prognosis and treatment of lung NETs.

RECENT FINDINGS

There have been no recently identified molecular prognostic factors for lung NETs and none that have been routinely used to guide management of patients with lung NETs. Previous findings suggest that patients with loss of chromosome 11q may have a worse prognosis along with upregulation of anti-apoptotic pathways (e.g., loss of CD44 and OTP protein expression). Lung NETs rarely harbor driver mutations commonly found in non-small cell lung cancer (NSCLC) or TP53/RB1 mutations found universally in small cell lung cancer. Lung NETs also have low tumor mutation burden and low PD-L1 expression. Everolimus, an mTOR inhibitor and the only FDA approved therapy for unresectable lung NETs, is an effective treatment but the presence of a molecular alteration in the PI3K/AKT/mTOR pathway is not known to predict treatment response. The predominant mutations in lung NETs occur in genes regulating chromatin remodeling and histone modification, with potential targeted therapies emerging in clinical trials. Lung NETs have recurring alterations in genes that regulate the epigenome. Future targeted therapy interfering with epigenetic pathways may hold promise.

Diagnosis of atypical carcinoid can be made on biopsies > 4 mm2 and is accurate

In the 2021 WHO thoracic tumors, gradation of lung carcinoids in biopsies is discouraged. We hypothesized that atypical carcinoid (AC) could be reliably diagnosed in larger preoperative biopsies. Biopsy-resection paired specimens of carcinoid patients were included, and definitive diagnosis was based on the resection specimen according to the WHO 2021 classification. A total of 64 biopsy-resection pairs (26 typical carcinoid (TC) (41%) and 38 AC (59%)) were analyzed. In 35 patients (55%), tumor classification between the biopsy and resection specimen was concordant (26 TC, 9 AC). The discordance in the remaining 29 biopsies (45%, 29 TC, 0 AC) was caused by misclassification of AC as TC. In biopsies measuring < 4 mm², 15/15 AC (100%) were misclassified compared to 14/23 AC (61%) of biopsies ≥ 4 mm². Categorical concordance of Ki-67 in biopsy-resection pairs at threshold of 5% was 68%. Ki-67 in the biopsy was not of additional value to discriminate between TC and AC, irrespective of the biopsy size. Atypical carcinoid is frequently missed in small bronchial biopsies (< 4 mm²). If the carcinoid classification is clinically relevant, a cumulative biopsy size of at least 4 mm² should be considered. Our study provides strong arguments to make the diagnosis of AC in case of sufficient mitosis for AC on a biopsy and keep the diagnosis "carcinoid NOS" for carcinoids with ≤ 1 mitosis per 2 mm². Ki-67 has a good concordance but was not discriminative for definitive diagnosis.

Atypical carcinoid with multiple central airway metastases: A case report

A 51-year-old man was found to have multiple polypoid tracheal and bilateral main bronchial tumors during postoperative follow-up of atypical carcinoid. He underwent transtracheal biopsy, and was diagnosed as having central airway metastases of the atypical carcinoid. He underwent chemotherapy, but the effects were unfavorable. Owing to the risk of airway obstruction, he was referred to our hospital for interventional bronchoscopy. Carcinoid tumors usually present as peripheral lung lesions or solitary endobronchial abnormalities, but rarely appear as multiple central airway lesions. We present a very rare case of multiple central airway metastases of atypical carcinoid, controlled by bronchoscopic treatment.

Morbidity and extent of surgical resection of carcinoid tumors after endobronchial treatment

OBJECTIVES

This study assessed whether endobronchial therapy (EBT) for bronchial carcinoid, if not curative, reduces the extent of the surgical resection and whether EBT is associated with increased surgical morbidity.

MATERIAL AND METHODS

Analysis was performed in a cohort of patients with bronchial carcinoid who have undergone surgical resection. A group that underwent EBT before the surgery (S + EBT) was compared with a group where no EBT was performed (S-EBT). Postoperative complications were also compared between both groups.

RESULTS

A total of 254 patients treated for a bronchial carcinoid tumor between 2003 and 2019 were screened for inclusion. A total of 65 surgically treated patients were included, of whom 41 (63%) underwent EBT prior to surgery. In 5 out of 41 patients (12%) from the S + EBT group, less parenchyma was resected versus 2 out of 24 (8%) from the S-EBT group (OR 1.528, 95% CI 0.273-8.562, p = 1.000). Two patients from the S + EBT group (5%) underwent lobectomy instead of sleeve lobectomy versus 0 from the S-EBT group (OR 1.051, 95% CI 0.981-1.127, p = 0.527). Comparing complications between the S + EBT and S-EBT group did not result in increased postoperative surgical morbidity (15% S + EBT, 24% S-EBT).

CONCLUSION

EBT, if not curative, does not reduce the extent of the subsequent surgical resection. Therefore, if curative EBT is not anticipated, patients should directly be referred for surgery. If curative EBT seems feasible, it should be attempted not only because surgical resection can be prevented, but also because failure of EBT is not associated with excess surgical morbidity.

Prognostic significance of histopathological factors in survival and recurrence of atypical carcinoid tumours

OBJECTIVES

Atypical carcinoids are neuroendocrine neoplasms of intermediate degree and low frequency. The aim of this study is to analyse their clinical characteristics and the importance of different histopathological factors in their prognosis.

METHODS

Multicentre cooperative group EMETNE prospectively reviewed 153 patients operated on between 1998 and 2016 with diagnosis of atypical carcinoids. Clinical variables and histopathological features were assessed.

RESULTS

Mean age was 54.36 years, similar for both genders. Concerning pathological study, mean tumour size was 31.7 mm. Rosettes were presented in 17% of the cases and tumoural necrosis in 23.3%. The cell proliferation factor Ki-67 index was 10.7%. The 2- and 5-year overall survival rates were 95.8% and 88.9%, respectively. In the univariate study, statistically significant differences in survival were found for each of the categories of T, N and M factors. Mitotic index and quantification of expression of Ki-67 showed influence in overall survival, although without statistical significance. In the multivariate analysis, factors N, M and mitotic index behaved as independent prognostic factors related to survival. Median disease-free interval in the series was 163.35 months. In cases with loco-regional recurrence, 53% had positive hiliar or mediastinal nodal involvement at the time of the surgery. In the univariate analysis, we observed statistically significant differences in disease-free interval in patients with nodal involvement (P = 0.024) and non-anatomical resections (P = 0.04). Histological characteristics showed no statistically significant differences in disease-free interval.

CONCLUSIONS

Lymph node involvement, the development of distant metastasis and mitotic index, more than Ki-67 determination, were shown as independent prognostic factors related to survival of these patients.

Pigmented spindle cell variant of a thymic atypical carcinoid in an octogenarian

Background

A pigmented carcinoid is an extremely rare variant of carcinoid characterized by melanin pigmentation of the tumor, with only five cases described in the literature. In addition, thymic carcinoids are rare in elderly patients and their prognosis after resection of the carcinoid tumor is unclear.

Case presentation

An anterior mediastinal tumor was incidentally found in an 82-year-old man who had been diagnosed with acute thoracic empyema. The tumor was considered most likely to be a noninvasive thymoma or thymic carcinoma for which surgery was indicated after the resolution of the empyema. The tumor was completely resected 4 months after the empyema surgery, and the patient had an uneventful postoperative course. A cut surface of the resected specimen was extensively pigmented and appeared dark-brownish, with abundant melanin pigmentation later confirmed in the spindle-shaped tumor cells. Based on the histologic examination and immunohistochemical study, melanoma was eliminated as a differential diagnosis and the tumor was diagnosed as a pigmented atypical carcinoid of the thymus.

Conclusions

This report provides additional knowledge on thymic pigmented carcinoids and thymic atypical carcinoids in elderly patients.

Typical and atypical carcinoid tumors of the lung: a clinicopathological correlation of 783 cases with emphasis on histological features

We present 783 surgical resections of typical and atypical carcinoid tumors of the lung identified in the pathology files of 20 different pathology departments. All cases were critically reviewed for clinical and pathological features and further correlated with clinical outcomes. Long-term follow-up was obtained in all the patients and statistically analyzed to determine significance of the different parameters evaluated. Of the histopathological features analyzed, the presence of mitotic activity of 4 mitoses or more per 2 mm², necrosis, lymphatic invasion, and lymph node metastasis were identified as statistically significant. Tumors measuring 3 cm or more were also identified as statistically significant and correlated with clinical outcomes. Based on our analysis, we consider that the separation of low- and intermediate-grade neuroendocrine neoplasms of the lung needs to be readjusted in terms of mitotic count as the risk of overgrading these neoplasms exceeds 10% under the current criteria. We also consider that tumor size is an important feature to be considered in the assessment of these neoplasms and together with the histological grade of the tumor offers important features that can be correlated with clinical outcomes.

A case of atypical thymic carcinoid mimicking a paraganglioma

BACKGROUND

Thymic atypical carcinoid has high recurrence and metastasis rates due to frequent lymph node metastases. The aim of the study is to report a case of atypical thymic carcinoid mimicking a paraganglioma and to further explain the benefits of using median sternotomy (MS) approach even in thymic epithelial tumours (TETs) sized less than 5 cm.

CASE PRESENTATION

The patient was a 59-year-old asymptomatic man. During a medical check-up, positron emission tomography/computed tomography (PET/CT) showed a 4.5 cm-diameter thymus with remarkable uptake. Thoracic surgery was performed to completely remove the tumour with lymph node dissection using MS because of possible malignancy. Although MS is accepted as the standard approach for TETs, minimally invasive thoracotomy (MIT) has emerged over recent decades. Maintaining surgical safety is priority; MIT is generally selected in <5-cm-diameter tumours. Here, we considered that the tumour could be resected using MIT. However, because PET/CT showed marked uptake, we selected the MS approach. Thus, MS can be applied even for small-sized TETs.

CONCLUSION

Thymic atypical carcinoid should be considered when PET/CT shows high-uptake tumours in the anterior mediastinum. Clinicians should consider using the MS approach, even if the tumour is <5 cm.

Capecitabine and Temozolomide in Advanced Lung Neuroendocrine Neoplasms

BACKGROUND

Patients with advanced lung neuroendocrine neoplasms (NENs) have few treatment options. Capecitabine and temozolomide have recently showed significant activity in patients with pancreatic neuroendocrine tumors (NETs), but data in lung NETs are limited.

METHODS

We retrospectively reviewed the records of patients treated at a large referral center to identify patients seen between January 2008 and September 2018 with metastatic lung NENs who received treatment with capecitabine and temozolomide (CAPTEM). Patients with small cell lung cancer were excluded. The primary endpoint was overall response rate per RECIST 1.1. Secondary endpoints included progression-free survival, overall survival, and toxicity.

RESULTS

Twenty patients were identified who received treatment with capecitabine and temozolomide. Fourteen (70%) had typical lung NETs, five had (25%) atypical carcinoids, and one (5%) had disease defined as a large-cell neuroendocrine carcinoma. Nineteen patients were evaluable for response. Six (30%) patients exhibited a best response of partial response per RECIST 1.1 criteria, 11 (55%) stable disease, and 2 (10%) progressive disease; objective response rate was 30%, and disease control rate was 85%. Eleven patients eventually progressed, only six of whom exhibited progression per RECIST 1.1 criteria. Median progression-free survival was 13 months (95% confidence interval [CI], 4.4-21.6 months). Median overall survival was 68 months (95% CI, 35.3-100.7 months). Toxicity profile was mild with mainly grade 1, expected toxicities. Six patients required dose reduction because of toxicity.

CONCLUSION

The CAPTEM regimen is associated with a high response rate and a relatively tolerable toxicity profile in lung NENs. This regimen warrants further exploration in a prospective clinical trial.

IMPLICATIONS FOR PRACTICE

Patients with advanced lung neuroendocrine neoplasms have very few systemic treatment options. The capecitabine and temozolomide regimen has previously shown significant activity in patients with pancreatic neuroendocrine tumors (NETs) but has not been explored in metastatic lung NETs. This study showed that this regimen is associated with a high response rate (30%) and a relatively tolerable toxicity profile in this population.

The role of surgery for atypical bronchopulmonary carcinoid tumor: Development and validation of a model based on Surveillance, Epidemiology, and End Results (SEER) database

OBJECTIVES

The rarity of atypical carcinoid (AC) of lung and the lack of prospective clinical trials lead to limited knowledge of its biology, treatment information and prognosis. The current study analyzed AC patients from the Surveillance, Epidemiology, and End Results (SEER) database to better understand the clinical characteristics of this disease and build a prognostic nomogram for clinical practice.

MATERIALS AND METHODS

A total of 507 AC patients with pathological confirmation from SEER database were performed with univariate Cox regression analyses for both overall survival (OS) and lung cancer specific survival (LCSS) analyses. Of the 507 observations, 464 were used in the multivariable Cox proportional hazards model as training cohort of new nomogram. A new nomogram was constructed based on the training cohort and validated by an external validation cohort to predict the 3-, 5- and 10-year OS of ACs. The accuracy and clinical practicability were separately tested by Harrell's C-indexes, calibration plots and decision curve analyses (DCA).

RESULTS

Lobectomy and segmental resection were found to be protective factors for AC patients. Age, primary tumor size, N stage, M stage, surgery and regional lymph nodes examination were shown as significant prognostic factors in Cox regression analyses and included in the nomogram as predictors. The C-index in the training cohort for 3-, 5-, and 10-year OS were 0.722, 0.737 and 0.712, respectively. The internal and external calibration plots for predictions of the 3-, 5-, and 10-year OS were in excellent agreement. An online webserver was built based on the proposed nomogram for convenient clinical use.

CONCLUSION

AC patients with lobectomy or segmental resection tended to have better OS and LCSS. A nomogram was constructed and validated to predict the OS for AC patients and to provide accurate and individualized survival predictions.

A case of primary pulmonary atypical carcinoid with EML4-ALK rearrangement

Targeted therapy has revolutionized the treatment pattern of advanced drive gene mutation positive non-small cell lung cancer (NSCLC). Advanced testing techniques enable physicians to detect these gene alterations in the clinic, thereby offering targeted therapies as treatment options to their patients. In this article, we reported a 52-year-old Chinese female with a pulmonary nodule in her left lower lung. After thoracoscopic lobectomy, a histopathological diagnosis of moderately differentiated atypical carcinoid (AC) was made. Anaplastic lymphoma kinase (ALK) rearrangement was detected, which is a rare phenomenon in AC. After the failure of chemotherapy and radiotherapy, the patient started taking crizotinib, subsequently with ceritinib, and then alectinib. This sequential therapy approach has significant clinical benefits for the patient. This article reviewed the clinical significance and drug resistance mechanism of ALK rearrangement in lung cancer. We also discussed recent and ongoing researches and applications of ALK-tyrosine kinase inhibitors (ALK-TKIs).

Neuroendocrine Tumors of the Lung: Updates and Diagnostic Pitfalls

Neuroendocrine tumors of the lung constitute approximately 20% of all primary lung tumors and include typical carcinoid, atypical carcinoid, small cell carcinoma, and large cell neuroendocrine carcinoma. Given their morphologic overlap with diverse mimics, neuroendocrine tumors of the lung can be diagnostically challenging. This review discusses the clinical, histologic, immunophenotypic, and molecular features of pulmonary neuroendocrine tumors, along with common diagnostic pitfalls and strategies for avoidance.

Spread through air spaces (STAS) is a predictor of poor outcome in atypical carcinoids of the lung

Spread through air spaces (STAS) have been recently recognized as a prognostic factor for adenocarcinoma and squamous cell carcinoma of the lung. Pulmonary neuroendocrine neoplasms (NENs) include tumors with different morphology and a heterogeneous clinical behavior. Among atypical carcinoids (ACs), new prognostic factors able to refine prognosis are needed. In the present study, a retrospective series of 91 surgically resected ACs was investigated, in parallel with 191 control cases of typical carcinoids (TCs) and of high-grade small- and large-cell neuroendocrine carcinomas, to assess the presence and potential prognostic role of STAS. STAS was defined by the presence of neoplastic nests or single cells in air spaces beyond the tumor edge. Clinicopathological parameters and survival were correlated by univariate and multivariate analyses. STAS was identified in 48% of ACs (44/91) compared to 20.5% of TCs and 71-88% of high-grade large- and small-cell carcinomas in the control group. In the carcinoid group, presence of STAS was significantly correlated with unfavorable parameters, such as high tumor stage, positive nodal status, high Ki-67 index, presence of angioinvasion, and with adverse disease outcome, shorter overall survival, and time to progression. In conclusion, the presence of STAS is an additional relevant adverse prognostic factor in pulmonary AC that currently has the most unpredictable outcome and the most controversial treatment strategy.

Atypical carcinoid tumor of the lung: A rare entity

Carcinoids account for approximately 2% of all lung tumors, and the atypical carcinoids (ACs) are much rarer than typical carcinoid. Here, we report a rare case of AC tumor of the lung. A 50-year-old female patient presented with left-sided chest pain for 1 year, cough for 6 months, and loss of appetite for 6 months. Contrast-enhanced computed tomography scan of the thorax revealed an ill-defined heterogeneously enhancing soft-tissue attenuation lesion in the mediastinum following which transthoracic biopsy was done. Histomorphology and immunohistochemistry were consistent with AC, a neuroendocrine tumor. Combination chemotherapy consisting of cisplatin and etoposide was administered as initial chemotherapy.

Characteristics of 252 patients with bronchopulmonary neuroendocrine tumours treated at the Copenhagen NET Centre of Excellence

BACKGROUND

Bronchopulmonary neuroendocrine tumours are divided into typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung cancer (SCLC).

AIM

To thoroughly describe a cohort of 252 patients with TC, AC and LCNEC (SCLC excluded).

MATERIAL AND METHODS

Collection of data from 252 patients referred to and treated at Rigshospitalet 2008-2016. Data was collected from electronic patient files and our prospective NET database. Statistics were performed in SPSS.

RESULTS

162 (64%) had TC, 29 (12%) had AC and 61 (24%) had LCNEC. Median age at diagnosis was 69 years (range: 19-89) with no difference between genders. Thoraco-abdominal CT was performed in all patients at diagnosis. FDG-PET/CT was performed in 207 (82%) at diagnosis and was positive in 95% of the entire cohort, with no difference between tumour types. Synaptophysin was positive in 98%, chromogranin A in 92% and CD56 in 97%. Mean Ki67 index was 5% in TC, 16% in AC and 69% in LCNEC (p < 0.001). Metastatic disease was found in 4% of TC, 27% of AC and 58% of LCNEC at time of initial diagnosis (p < 0.001). In total 179 patients (71%) underwent surgical resection; TC: 87%, AC: 72% and LCNEC: 28% (p < 0.001). Of the resected patients, 11 (6%) had recurrence. Five-year survival rate was 88% for TC, 63% for AC and 20% for LCNEC.

CONCLUSION

In this comprehensive study of a cohort of 252 patients, one of the largest until date, with TC, AC and LCNEC, the gender distribution showed female predominance with 68%. FDG-PET/CT was positive in 95% of the patients independent of tumour type, which confirms that FDG-PET/CT should be a part of the preoperative work-up for TC, AC and LCNEC. Tumour type was the single most potent independent prognostic factor.

Atypical carcinoid localized at the bronchus accompanied by diffuse idiopathic pulmonary neuroendocrine cell hyperplasia in the distal lung: a rare case report

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is hyperplasia of noninvasive neuroendocrine cells originating from Kultchitsky cells. This is a rare pathological condition, suspected to be a precursor lesion of carcinoid, together with tumorlet. In the WHO histological classification (4th edition) revised in 2015, DIPNECH was added to the category that includes neuroendocrine tumors. Our patient was a 77-year-old woman who initially visited another doctor because of coughing. Chest CT revealed a mass occluding the right intermediate bronchial trunk, and bronchial carcinoid was suspected from biopsy findings, leading to referral of this patient to our department. The tumor was excised under a rigid bronchoscope for the purpose of making a definitive histological diagnosis and determining the extent of spread. The stalk portion of the tumor extended from the bifurcation of the middle and lower lobe bronchi in the membranous part of the intermediate trunk to the central side. The airway appeared to be almost completely occluded under bronchoscopy, but aeration from the periphery was maintained. Histopathologically, there was hyperplasia of oval atypical cells with relatively poor cytoplasm beneath the bronchial mucosa on HE staining, suggesting neuroendocrine tumor. Immunostaining revealed that these cells were positive for CD56, chromogranin A, and synaptophysin, and that there was moderate mitosis, leading to a diagnosis of atypical carcinoid. At a later date, radical surgery comprised of right pulmonary middle and lower lobectomy and lymph node dissection was performed. The final histopathological diagnosis was atypical carcinoid of the bronchus (pT1aN0M0, stage IA). There were multiple aggregations of atypical cells, measuring approximately 1-3 mm, along the airway around the bronchioles in the excised lung, indicating concomitant DIPNECH. The patient currently has no evidence of either recurrence or metastasis at 12 months after surgery, but we will continue meticulous follow-up.

Low Grade Neuroendocrine Tumors of the Lung

The lung is the second most common site of neuroendocrine tumors (NETs). Typical and atypical carcinoids are low-grade NETs of the lung. They present a favorable prognosis comported to the more common high-grade NETs. The low- and high-grade NETs require different treatment strategies; effective management of these tumors is essential to prolong survival and to manage the symptoms in patients with secretory or functional tumors. These rare tumors have received little attention and education is needed for treating physicians. This mini-review will concentrate mainly on advanced low-grade lung NETs. The article describes the classification of lung NETs and the diagnostic work-up. Different treatment methods including somatostatin analogs, peptide receptor radioligand therapy, and biologic systemic therapy are discussed. Promising results from recent trials are presented and discussed in the context of the lung primary site.

Thymus neuroendocrine tumors with CTNNB1 gene mutations, disarrayed ß-catenin expression, and dual intra-tumor Ki-67 labeling index compartmentalization challenge the concept of secondary high-grade neuroendocrine tumor: a paradigm shift

We herein report an uncommon association of intimately admixed atypical carcinoid (AC) and large cell neuroendocrine (NE) carcinoma (LCNEC) of the thymus, occurring in two 20- and 39-year-old Caucasian males. Both tumors were treated by maximal thymectomy. The younger patient presented with a synchronous lesion and died of disease after 9 months, while the other patient was associated with a recurrent ectopic adrenocorticotropic hormone Cushing's syndrome and is alive with disease at the 2-year follow-up. MEN1 syndrome was excluded in either case. Immunohistochemically, disarrayed cytoplasmic and nuclear ß-catenin expression was seen alongside an intra-tumor Ki-67 antigen labeling index (LI) ranging from 2 to 80% in the younger patient's tumor and from 3 to 45% in the other. Both exhibited upregulated cyclin D1 and retinoblastoma, while vimentin was overexpressed in the recurrent LCNEC only. Next-generation sequencing revealed CTNNB1, TP53, and JAK3 mutations in the synchronous tumor and CTNNB1 mutation alone in the metachronous tumor (the latter with the same mutation as the first tumor of 17 years prior). None of the 23 T-NET controls exhibited this hallmarking triple alteration (p = 0.003). These findings suggested that LCNEC components developed from pre-existing CTNNB1-mutated AC upon loss-of-function TP53 and gain-of-function JAK3 mutations in one case and an epithelial-mesenchymal transition upon vimentin overexpression in the other case. Both tumors maintained intact cyclin D1-retinoblastoma machinery. Our report challenges the concept of secondary LCNEC as an entity that develops from pre-existing AC as a result of tumor progression, suggesting a paradigm shift to the current pathogenesis of NET.

Incidental metastatic mediastinal atypical carcinoid in a patient with parathyroid adenoma: a case report

Background

Atypical carcinoid arising from the mediastinal tissue is a rare neuroendocrine tumor and an association with parathyroid adenoma is very unusual. We report an unusual case of atypical carcinoid of mediastinum with metastasis in a patient presenting with parathyroid adenoma, which is the first case to be reported from Pakistan.

Case presentation

A 51-year-old Pakistani man was seen in postoperative intensive care after right parathyroidectomy and mediastinal mass resection for the management of postoperative hypocalcaemia. He had a background history of dyspnea. Examination was unremarkable. Preoperative laboratory evaluation revealed a calcium level of 12.7 mg/dl, phosphate of 1.9 mg/dl, serum albumin of 4.8 g/dl, alkaline phosphate of 94 U/L, and serum intact parathyroid hormone level 413.8 pg/ml. A technetium-99m sestamibi parathyroid scan showed right parathyroid increased tracer uptake. Further workup revealed a large mediastinal mass which was diagnosed as atypical carcinoid after Tru-Cut biopsy. He underwent right-sided parathyroidectomy and resection of the mediastinal mass. The histopathology confirmed it to be a parathyroid adenoma and atypical carcinoid tumor of his mediastinum with metastasis in his lymph node and parathyroid gland. Somatostatin receptor scintigraphy revealed a well-defined focus in his left hypochondriac region consistent with a somatostatin receptor scintigraphy-avid tumor. He was started on everolimus and planned for octreotide therapy.

Conclusions

We describe an incidental finding of atypical carcinoid of the mediastinum in a patient diagnosed as having parathyroid adenoma. Clinical manifestations of neuroendocrine syndromes are challenging. Some tumors cluster in a non-classic description with other common neoplasms. They rarely present in isolation, remain clinically silent, and need aggressive workup with the aid of imaging and histopathology.

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.

Bronchial and Thymic Carcinoid Tumors. Hematol Oncol Clin North Am. 2016;30:83-102. [PMID: 26614370 DOI: 10.1016/j.hoc.2015.09.003]

Bronchial and thymic carcinoids are rare. We present epidemiologic data and potential risk factors. The approach to bronchial and thymic carcinoid patients is discussed, from the initial diagnosis and evaluations to treatment. These malignancies follow staging systems of their site of origin. Because bronchial and thymic carcinoids are rare, we use many treatment strategies that have been demonstrated in gastrointestinal and pancreatic neuroendocrine tumors. The lack of information regarding efficacy in bronchial and thymic carcinoids, as well as the scarcity of therapeutic options available, demands the importance of clinical trials that include these patients.

Neuroendocrine Cancer of the Lung: A Diagnostic Puzzle

Here we report the case of a pulmonary neuroendocrine tumor (pNET) in which the pathological diagnosis was revised several times over the course of the patient's disease because of atypical behavior of the tumor; consequently, the patient was treated with various treatment schedules.

Somatostatin receptor PET/CT in restaging of typical and atypical lung carcinoids

Background

To assess the role of somatostatin receptor (SR) PET/CT using Ga-68 DOTATOC or DOTATATE in staging and restaging of typical (TC) and atypical (AC) lung carcinoids.

Methods

Clinical and PET/CT data were retrospectively analyzed in 27 patients referred for staging (N = 5; TC, N = 4; AC, N = 1) or restaging (N = 22; TC, N = 8; AC, N = 14). Maximum standardized uptake value (SUVmax) of SR-positive lesions was normalized to the SUVmax of the liver to generate SUVratio; SR PET was compared to contrast-enhanced (ce) CT. The classification system proposed by Rindi et al. (Endocr Relat Cancer. 2014;21(1):1-16, 2014) was used for classification of patients in TC and AC groups.

Results

Only 18/27 patients were found to have metastases on PET/CT. Of the 186 lesions, 101 (54.3 %) were depicted on both PET and CT, 53 (28.5 %) lesions only on CT, and 32 (17.2 %) only on PET. SUVratio of lesions was significantly higher in AC as compared to TC (p < 0.001). In patients referred for restaging, additional findings on PET lead to upstaging with change in management strategy in 5/22 (22.7 %) patients (AC, N = 5; TC, N = 1). In four patients (all AC) referred for restaging and in one patient (TC) referred for staging, additional findings on CT missed on PET lead to correct staging.

Conclusions

Typical and atypical carcinoid patients have complex patterns of metastases which make it necessary to combine functional SR PET and contrast-enhanced CT for appropriate restaging. In patients referred for restaging SR, PET may have a relevant impact on treatment strategy in up to 22.7 of patients with typical and atypical lung carcinoids.

Primary laryngeal neuroendocrine carcinoma - a rare entity with deviant clinical presentation

Primary laryngeal neuroendocrine carcinomas are rare neoplasms. WHO classifies them under five categories of which, the moderately differentiated neuroendocrine carcinoma is synonymous with atypical or malignant carcinoid tumour. We report a rare case of primary laryngeal neuroendocrine carcinoma with an unusual and misleading clinical presentation. The initial cytological diagnosis of secondary neuroendocrine carcinoma in the cervical lymph node led to the suspicion of primary neuroendocrine carcinoma in the larynx.

Pathology and diagnosis of neuroendocrine tumors: lung neuroendocrine

Neuroendocrine (NE) tumors of the lung include a spectrum from low-grade typical carcinoid (TC) and intermediate-grade atypical carcinoid (AC) to high-grade large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Although NE lung tumors are frequently discussed together, as in this article, carcinoids are very different from high-grade SCLC and LCNEC. SCLC and LCNEC are found in heavy-smoking, older patients, whereas smoking is not strongly associated with carcinoid tumors. On a molecular level, SCLC and LCNEC have extensive genetic abnormalities, but there are few in TC and slightly more in AC.

Chemotherapy for locally advanced and metastatic pulmonary carcinoid tumors

OBJECTIVES

The optimal management of locally advanced and metastatic pulmonary carcinoid tumors remains to be determined.

MATERIALS AND METHODS

A retrospective review was conducted on patients with typical and atypical pulmonary carcinoid tumors treated at our institutions between 1990 and 2012.

RESULTS

300 patients were identified with pulmonary carcinoid, (80 patients with atypical carcinoid), of whom 29 presented with metastatic disease (16 atypical). Of evaluable patients, 26 (41%) with stages I-III atypical carcinoid tumors recurred at a median time of 3.7 years (range, 0.4-32), compared to 3 (1%) patients with typical carcinoid (range, 8-12.3). 39 patients were treated with chemotherapy, including 30 patients with metastatic disease (27 atypical), and 7 patients were treated with adjuvant platinum-etoposide chemoradiation (6 atypical, 1 typical, 6 stage IIIA, 1 stage IIB). At a median follow-up of 2 years there were 2 recurrences in the 7 patients receiving adjuvant treatment. Median survival after diagnosis of metastatic disease for patients with atypical pulmonary carcinoid was 3.3 years with a 5-year survival of 24%. Treatment regimens showing efficacy in pulmonary carcinoid include 15 patients treated with octreotide-based therapies (10% response rate (RR), 70% disease control rate (DCR), 15 month median progression-free survival (PFS)), 13 patients treated with etoposide+platinum (23% RR, 69% DCR, 7 month median PFS), and 14 patients treated with temozolomide-based therapies (14% RR, 57% DCR, 10 month median PFS). 8 of 10 patients with octreotide-avid disease treated with an octreotide-based regimen experienced disease control (1 partial response, 7 stable disease) for a median of 18 months (range 6-72 months).

CONCLUSIONS

These results support our previous finding that a subset of pulmonary carcinoid tumors are responsive to chemotherapy.

Atypical carcinoid of larynx: a case study and a brief review

Atypical Carcinoids, Malignancy arising from neuroendocrine cells are among the non-Epidermoid cancers of larynx.The present study reports an interesting and rare case of atypical carcinoid of larynx. An 85-year-old male patient presented with a history of dysphagia.On clinical examination, a provisional diagnosis of cyst larynx was made. But during surgery, the Diagnosis had to be reviewed as benign lesion of the larynx. Histopathological diagnosis was atypical carcinoid. The present study discusses the unusual presentation and unusual clinical diagnosis of these neuroendocrine neoplasms of larynx.

Neuroendocrine carcinoma of supraglottis - A case report

Neuroendocrine carcinoma of the larynx is a rare entity constituting about 0.6% of all laryngeal malignancies. An interesting case of neuroendocrine carcinoma of supraglottis in a 70 year old lady is being reported.