Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH): Prevalence, clinicopathological characteristics and survival outcome in a cohort of 311 patients with well-differentiated lung neuroendocrine tumours

[Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH)]

INTRODUCTION

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare, chronic condition that predominantly affects women over the age of 60.

CURRENT KNOWLEDGE

DIPNECH combines non-specific clinical signs (chronic cough, dyspnea), bronchial obstruction on PFT and signs suggestive of bronchiolitis on chest CT associated with nodules and multiple micronodules. The diagnosis is most often histological, associating neuroendocrine cell hyperplasia, tumorlets and, inconsistently, carcinoid tumors and constrictive bronchiolitis.

PROSPECTS

There are currently no recommendations for DIPNECH treatment and the literature is limited to case reports and retrospective series. Inhibitors of mTOR and somatostatin analogs are possible treatments requiring validation by clinical trials. Functional follow-up and CT scan monitoring are necessary in order to detect complications.

CONCLUSIONS

DIPNECH is a rare, usually insidious pathology, and may in some cases expose the patient to a risk of tumor and chronic respiratory failure. The diagnosis should be made in the event of a chronic cough in a middle-aged woman.

Identification of Defined Molecular Subgroups on the Basis of Immunohistochemical Analyses and Potential Therapeutic Vulnerabilities of Pulmonary Carcinoids

INTRODUCTION

Multi-omic studies have identified three molecular separated pulmonary carcinoid (PC) subgroups (A1, A2, B) with distinctive mRNA expression profiles (e.g., orthopedia homeobox protein [OTP], achaete-scute homolog [ASCL1], and hepatocyte nuclear factor 1 homeobox A [HNF1A]). We aimed to establish an immunohistochemical (IHC) biomarker panel that enables subgroup identification, and assessment of its potential clinical relevance.

METHODS

All patients with resected pulmonary carcinoids (2003-2012) were identified from the Dutch Cancer/Pathology Registry, and tumors were revised. The IHC expression of OTP, ASCL1, and HNF1A was scored in a blinded fashion in a mRNA-profiled (n = 5 per subgroup) and national carcinoid cohort (N = 478). The expression of potential therapeutic targets (somatostatin receptor type 2a [SSTR2A] and delta-like canonical Notch ligand 3 [DLL3]) was assessed. Immunohistochemistry was assessed using H-scoring.

RESULTS

OTP, ASCL1, and HNF1A reported similar IHC and mRNA expression patterns in the matched primary samples. In the national cohort, IHC separated PCs into subgroups A1 (n = 224 [53%], OTPhigh-ASCL1high-HNF1Alow), A2 (n = 161 [38%], OTPhigh-ASCL1low-HNF1Ahigh), and B (n = 37 [9%], OTPlow-ASCL1low-HNF1Ahigh). In 12% of PCs, no distinct classification could be provided. Patients with A1 were enriched for older age (83% > 50 y), female individuals (83%), and peripheral location (55%) with low SSTR2A (median = 10) and high DLL3 (median = 52) expression. A2 included younger patients (34% < 40 y) and endobronchial/central (87%) tumors with high SSTR2A (median = 160), but low DLL3 (median 0) expression. Group B included more male individuals (59%) and recurrence was more frequent (19%) than in groups A1 (8%) and A2 (6%). Neuroendocrine cell hyperplasia was enriched in A1 (25%) compared with A2 (3%) and B (0%).

CONCLUSIONS

An OTP, ASCL1, and HNF1A IHC panel enables the identification of molecular-defined pulmonary carcinoid subgroups with distinct clinical phenotypes and diverging therapeutic vulnerabilities that require further prospective evaluation.

Pulmonary neuroendocrine neoplasms: the molecular landscape, therapeutic challenges, and diagnosis and management strategies

Lung neuroendocrine neoplasms are a group of diverse, heterogeneous tumours that range from well-differentiated, low-grade neuroendocrine tumours-such as typical and atypical carcinoids-to high-grade, poorly differentiated aggressive malignancies, such as large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC). While the incidence of SCLC has decreased, the worldwide incidence of other pulmonary neuroendocrine neoplasms has been increasing over the past decades. In addition to the standard histopathological classification of lung neuroendocrine neoplasms, the introduction of molecular and sequencing techniques has led to new advances in understanding the biology of these diseases and might influence future classifications and staging that can subsequently improve management guidelines in the adjuvant or metastatic settings. Due to the rarity of neuroendocrine neoplasms, there is a paucity of prospective studies that focus on the lungs, especially in rare, well-differentiated carcinoids and LCNECs. In contrast with the success of targeted therapies in non-small-cell lung cancer (NSCLC), high-grade neuroendocrine carcinomas of the lung often only have a few specific targetable gene alterations. Optimal therapy for LCNECs is not well defined and treatment recommendations are based on extrapolating guidelines for the management of patients with SCLC and NSCLC. This Review explores the epidemiology, diagnosis, and staging of lung neuroendocrine neoplasms to date. In addition, we focus on the evolving molecular landscape and biomarkers, ranging from tumour phenotypes to functional imaging studies and novel molecular biomarkers. We outline the various clinical outcomes, challenges, the treatment landscape, ongoing clinical trials, and future directions.

Unmasking the unexpected: an unusual cause of refractory chronic cough

Diffuse pulmonary neuroendocrine hyperplasia is a rare condition that most commonly presents with a dry cough. It can mimic late-onset asthma, but airflow obstruction is usually fixed and nodules are likely to be present on CT imaging. https://bit.ly/4eymlxW.

Coexistence of DIPNECH with pulmonary adenocarcinoma: Coincidence or by design?

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) coexisting with pulmonary adenocarcinoma (ADC) is rare. Herein, we report a new case and review the cases published previously in the English literature. The clinicopathological features of similar cases reported in the English literature were summarized, and a putative association between DIPNECH and pulmonary ADC was suggested. Among the 22 cases studied, the majority of patients were female and older adults. DIPNECH lesions were usually recognized beyond the lobe or segment in which the ADC was located. Most ADCs were of a low- or intermediate-grade. DIPNECH and pulmonary ADC were interspersed in six patients. In particular, two cases of ADC showed neuroendocrine differentiation. We consider that DIPNECH accompanied by ADC is not coincidental, and that the two lesions may have a causal relationship. Analogous to the tumor histogenesis association of large cell neuroendocrine carcinoma/small cell carcinoma with ADC, we hypothesized that DIPNECH may also arise from a multipotent precursor cell and associate with a subgroup of ADC. However, further studies are required to explore this possibility.

An Illustrated Review of the Recent 2019 World Health Organization Classification of Neuroendocrine Neoplasms: A Radiologic and Pathologic Correlation

ABSTRACT

Recent advances in molecular pathology and an improved understanding of the etiology of neuroendocrine neoplasms (NENs) have given rise to an updated World Health Organization classification. Since gastroenteropancreatic NENs (GEP-NENs) are the most common forms of NENs and their incidence has been increasing constantly, they will be the focus of our attention. Here, we review the findings at the foundation of the new classification system, discuss how it impacts imaging research and radiological practice, and illustrate typical and atypical imaging and pathological findings. Gastroenteropancreatic NENs have a highly variable clinical course, which existing classification schemes based on proliferation rate were unable to fully capture. While well- and poorly differentiated NENs both express neuroendocrine markers, they are fundamentally different diseases, which may show similar proliferation rates. Genetic alterations specific to well-differentiated neuroendocrine tumors graded 1 to 3 and poorly differentiated neuroendocrine cancers of small cell and large-cell subtype have been identified. The new tumor classification places new demands and creates opportunities for radiologists to continue providing the clinically most relevant report and on researchers to design projects, which continue to be clinically applicable.

Sex Differences in the Survival of Patients with Neuroendocrine Neoplasms: A Comparative Study of Two National Databases

BACKGROUND

Neuroendocrine neoplasms (NENs) are increasing in incidence globally. Previous analysis of the UK cancer database (National Cancer Registration and Analysis Service (NCRAS)) showed a notable female survival advantage in most tumour sites. This study aims to compare NCRAS to the Surveillance, Epidemiology, and End Results Program (SEER) to validate these results using the same statistical methods.

METHODS

A total of 14,834 and 108,399 patients with NENs were extracted from NCRAS and SEER, respectively. Sixty-months survival for both males and females for each anatomical site of NENs were calculated using restricted mean survival time (RMST) and Kaplan-Meier Survival estimates. The sixty-month RMST female survival advantage (FSA) was calculated.

RESULTS

FSA was similar in NCRAS and SEER. The highest FSA occurred in lung and stomach NENs.

CONCLUSIONS

The data from SEER confirm the findings published by NCRAS. Female survival advantage remains unexplained.

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.

Updates on lung neuroendocrine neoplasm classification

Lung neuroendocrine neoplasms (NENs) are a heterogeneous group of pulmonary neoplasms showing different morphological patterns and clinical and biological characteristics. The World Health Organisation (WHO) classification of lung NENs has been recently updated as part of the broader attempt to uniform the classification of NENs. This much-needed update has come at a time when insights from seminal molecular characterisation studies revolutionised our understanding of the biological and pathological architecture of lung NENs, paving the way for the development of novel diagnostic techniques, prognostic factors and therapeutic approaches. In this challenging and rapidly evolving landscape, the relevance of the 2021 WHO classification has been recently questioned, particularly in terms of its morphology-orientated approach and its prognostic implications. Here, we provide a state-of-the-art review on the contemporary understanding of pulmonary NEN morphology and the potential contribution of artificial intelligence, the advances in NEN molecular profiling with their impact on the classification system and, finally, the key current and upcoming prognostic factors.

The Driver Role of Pathologists in Endocrine Oncology: What Clinicians Seek in Pathology Reports

Endocrine neoplasia represents an increasingly broad spectrum of disorders. Endocrine neoplasms range from incidental findings to potentially lethal malignancies. In this paper, we cover the impact of pathology in the interpretation of the clinic-pathological, genetic, and radiographic features underpinning these neoplasms. We highlight the critical role of multidisciplinary interactions in structuring a rational diagnostic and efficient therapeutic plan and emphasize the role of histopathological input in decision-making. In this context, standardized pathology reporting and second opinion endocrine pathology review represent relevant tools to improve the overall diagnostic workup of patients affected by endocrine tumors in every specific scenario. In fact, although a relevant proportion of cases may be correctly identified based on clinical presentation and biochemical/imaging investigations, a subset of cases presents with atypical findings that may lead to an inappropriate diagnosis and treatment plan based on a wrong pathological diagnosis if all pieces of the puzzle are not correctly considered. Pathologists have a responsibility to actively guide clinicians before and during surgical procedures to prevent unnecessary interventions. In all areas of endocrine pathology, pathologists must understand the complexity of tissue preservation and assay sensitivities and specificities to ensure the optimal quality and interpretation of diagnostic material. Finally, pathologists are central actors in tumor tissue biobanking, which is an expanding field in oncology that should be promoted while adhering to strict ethical and methodological standards.