Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia

A multi-lesional analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: a single-centre analysis

AIM

To conduct a multi-lesional computed tomography (CT) analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) patients to determine volumetric changes in lesions over 5 years.

MATERIALS AND METHODS

A retrospective case-note review was undertaken to identify 16 patients with histological and radiological features of DIPNECH between 2012-2021. Area and volume were calculated for 17 sets of lesions identified on high-resolution CT. Clinical data were extracted from electronic patient records, which included demographic data, outpatient clinic letters, histology reports, and imaging reports.

RESULTS

One hundred and twenty-eight lesions were identified in 16 patients (one male, 15 female) and followed-up annually over a median 1,985 days (range 1,450-2,290). At year 1 follow-up, lesion area ranged from 1-48 mm2, and lesion volume ranged from 8-18,380 mm3; lesion area ranged from 1-45mm2 and lesion volume ranged from 11-17,800 mm3 and year 5. Half (8/16) of the patients had concomitant typical carcinoid tumours and one patient had an atypical carcinoid tumour. No statistically significant correlation (p<0.05) was found between lesion cross-sectional area or volume and duration of follow-up (years and days). No metastatic spread was observed at the time of analysis.

CONCLUSIONS

No significant increase was observed in the size of over 100 lesions in patients with DIPNECH over a 5-year period and no metastasis occurred during the study period affirming the relatively indolent course of the disease.

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.

Lung Carcinoids: A Comprehensive Review for Clinicians

Lung carcinoids are neuroendocrine tumors, categorized as typical or atypical carcinoids based on their histological appearance. While most of these tumors are slow-growing neoplasms, they still possess malignant potential. Many patients are diagnosed incidentally on chest X-rays or CT scans. Presenting symptoms include cough, hemoptysis, wheezing, dyspnea, and recurrent pneumonia. Endocrine symptoms, such as carcinoid syndrome or ectopic Cushing's syndrome, are rare. Surgery is the primary treatment and should be considered in all patients with localized disease, even when thoracic lymph node metastases are present. Patients with distant metastases may be treated with somatostatin analogues, chemotherapy, preferably temozolomide-based, mTOR inhibitors, or peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE. Most patients have an excellent prognosis. Poor prognostic factors include atypical histology and lymph node metastases at diagnosis. Long-term follow-up is mandatory since metastases may occur late.

Quantitative Airway Assessment of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) on CT as a Novel Biomarker

Objectives: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) occurs due to abnormal proliferation of pulmonary neuroendocrine cells. We hypothesized that performing a quantitative analysis of airway features on chest CT may reveal differences to matched controls, which could ultimately help provide an imaging biomarker. Methods: A retrospective quantitative analysis of chest CTs in patients with DIPNECH and age matched controls was carried out using semi-automated post-processing software. Paired segmental airway and artery diameters were measured for each bronchopulmonary segment, and the airway:artery (AA) ratio, airway wall thickness:artery ratio (AWTA ratio) and wall area percentage (WAP) calculated. Nodule number, size, shape and location was recorded. Correlation between CT measurements and pulmonary function testing was performed. Results: 16 DIPNECH and 16 control subjects were analysed (all female, mean age 61.7 +/− 11.8 years), a combined total of 425 bronchopulmonary segments. The mean AwtA ratio, AA ratio and WAP for the DIPNECH group was 0.57, 1.18 and 68.8%, respectively, compared with 0.38, 1.03 and 58.3% in controls (p < 0.001, <0.001, 0.03, respectively). DIPNECH patients had more nodules than controls (22.4 +/− 32.6 vs. 3.6 +/− 3.6, p = 0.03). AA ratio correlated with FVC (R2 = 0.47, p = 0.02). A multivariable model incorporating nodule number, AA ratio and AWTA-ratio demonstrated good performance for discriminating DIPNECH and controls (AUC 0.971; 95% CI: 0.925−1.0). Conclusions: Quantitative CT airway analysis in patients with DIPNECH demonstrates increased airway wall thickness and airway:artery ratio compared to controls. Advances in knowledge: Quantitative CT measurement of airway wall thickening offers a potential imaging biomarker for treatment response.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH): a little known cause of thoracic lesions

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare but important condition to consider when investigating a patient with suspected thoracic malignancy. There is very little known about DIPNECH and it is considered to be a precursor to carcinoid tumour of the lung. This case report aims to increase awareness of this largely unknown and rare condition and to better improve its consideration as a differential diagnosis in patients who remain unresponsive to conventional treatment.

Lung adenocarcinoma coexisting with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia manifesting as multiple pulmonary nodules: A case report

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH), a rare condition, is characterized by pathological proliferation of neuroendocrine cells. Some of them are localized to the airway mucosa, and others locally infiltrate to form tumorlets and nodules. Here, we present a patient with lung adenocarcinoma accompanied by DIPNECH, making the latter difficult to distinguish from multiple pulmonary metastases. The patient, a 72-year-old Japanese woman, was diagnosed as having stage IVA lung adenocarcinoma because she had multiple nodules in both lungs. Mutation of epidermal growth factor receptor gene having been found in the primary tumor, treatment with osimertinib was started. This resulted in shrinkage of the primary tumor, but not the multiple pulmonary nodules. To determine whether these lung nodules were indeed lung metastases, we performed right upper lobectomy with lymphadenectomy and wedge resection of the right lower lobe. On pathological examination, the primary tumor was diagnosed as invasive adenocarcinoma, whereas the multiple pulmonary nodules were diagnosed as DIPNECH manifesting as tumorlets. Therefore, the final diagnosis was stage IA1 lung adenocarcinoma accompanied by DINPECH. The patient had no recurrences 1 year after the operation without any additional treatment. This is a rare case of lung adenocarcinoma accompanied by DIPNECH presenting as multiple pulmonary nodules. DIPNECH should be included in the differential diagnosis of multiple pulmonary nodules.

Prognostic Significance of Pulmonary Multifocal Neuroendocrine Proliferation With Typical Carcinoid

BACKGROUND

The clinical significance of multifocal pulmonary neuroendocrine proliferation (MNEP), including tumorlets and pulmonary neuroendocrine cell hyperplasia, in association with typical carcinoid (TC), is still debated.

METHODS

We evaluated a retrospective series of TC with long-term follow-up data prospectively collected from 2 institutions and compared the outcome between TC alone and MNEP plus TC. Several baseline covariates were imbalanced between the MNEP plus TC and TC groups; therefore, we conducted 1:1 propensity score matching and inverse probability of treatment weighting in the full sample. In the matched group, the association of clinical, respiratory, and work-related factors with the group was determined through univariable and multivariable conditional logistic regression analysis.

RESULTS

A total of 234 TC patients underwent surgery: 41 MNEP plus TC (17.5%) and 193 TC alone (82.5%). In the MNEP plus TC group, older age (P < .001), peripheral tumors (P = .0032), smaller tumor size (P = .011), and lymph node spread (P = .02) were observed compared with the TC group. Relapses occurred in 8 patients in the MNEP plus TC group (19.5%) and 7 in the TC group (3.6%). After matching, in 36 pairs of patients, a significantly higher 5-year progression-free rate was observed for the TC group (P < .01). Similar results were observed using inverse probability of treatment weighting in the full sample. The odds of being in the MNEP plus TC group was higher for those with work-related exposure to inhalant agents (P = .008), asthma or bronchitis (P = .002), emphysema, fibrosis, and inflammatory status (P = .032), or micronodules on the chest computed tomography scan and respiratory insufficiency (P = .036).

CONCLUSIONS

The association with MNEP seems to represent a clinically and prognostic relevant factor in TC. Hence, careful preoperative workup, systematic pathologic evaluation, including nontumorous lung parenchyma, and long-term postoperative follow-up should be recommended in these patients.

De-labeling severe asthma diagnosis: the challenge of DIPNECH

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary disease characterised by neuroendocrine cell hyperplasia within the bronchial epithelium [1]. The clinical presentation is characterised by nonspecific respiratory symptoms such as chronic cough, dyspnoea and bronchospasm. Given the rarity of the disease and the low specificity of symptoms, the diagnosis of DIPNECH is challenging and the time between symptom onset and diagnosis is long [1]. DIPNECH comprises a generalised proliferation of scattered neuroendocrine cells, small nodules (neuroendocrine bodies) or a linear proliferation of pulmonary neuroendocrine cells. It has been suggested that DIPNECH may mimic [2] or precede [3] asthma. The role of products of neuroendocrine cells such as substance P, which contribute to eosinophil migration, has been suggested to explain asthma symptoms in DIPNECH [3]. However, the characteristics of patients with DIPNECH who have symptoms suggestive of asthma have never been described. The aim of our study was to determine whether patients diagnosed with DIPNECH and initially referred for severe asthma management had specific characteristics.

DIPNECH is a differential diagnosis of severe asthma with no specific biomarkers. Chronic cough and multiple nodules on CT should prompt clinicians to consider this diagnosis. Differentiating DIPNECH from severe asthma remains crucial.https://bit.ly/3mmFbQn

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH): A Case of Indolent Pulmonary Nodules Diagnosed with Robotic-Assisted Navigational Bronchoscopy

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is an atypical pulmonary disorder with limited understanding. Given the rare nature of this disease, it is essential to obtain adequate tissue pathology to confirm the diagnosis. This disease is mainly diagnosed in middle-aged, nonsmoking females, and it is now accepted as a precursor lesion to pulmonary carcinoid tumors. DIPNECH presents with characteristic radiographic and histologic findings, but its diagnosis, management, and prognosis are often underrecognized and poorly understood. Those with symptoms may present with shortness of breath, wheezing, and persistent cough and are often misdiagnosed with reactive airway disease. Pulmonary function testing may reveal airflow obstruction and air trapping. Imaging is characterized by multiple lung nodules, typically less than 5 mm in size, with a background mosaic attenuation on computed tomography imaging. Histologically, DIPNECH can be suspected based on the presence of hyperplastic neuroendocrine cells. DIPNECH is considered a precursor to invasive neuroendocrine tumor, and up to 50% of patients may have a well-differentiated neuroendocrine tumor at the time of presentation. Here, we present the case of a 46-year-old female with a history of ulcerative colitis on mesalamine who presented with a 6-month history of ongoing shortness of breath, chest tightness, wheezing, and cough. She was initially diagnosed with asthma before imaging later revealed as multiple pulmonary nodules with a diffuse mosaic pattern. Using robotic-assisted navigational bronchoscopy, she underwent sampling of a dominant 1.8 cm right middle lobe pulmonary nodule and pathology was consistent with low-grade neuroendocrine tumor.

Is the combination of bilateral pulmonary nodules and mosaic attenuation on chest CT specific for DIPNECH?

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterized by multifocal proliferation of pulmonary neuroendocrine cells. On chest CT, DIPNECH exhibits bilateral pulmonary nodules and mosaic attenuation in most patients. We sought to: (1) assess the specificity of this pattern (i.e., bilateral pulmonary nodules together with mosaic attenuation) for DIPNECH; (2) describe its differential diagnosis; and (3) identify the clinico-radiologic features that may help prioritize DIPNECH over other diagnostic considerations.

Methods

We searched the Mayo Clinic records from 2015 to 2019 for patients with bilateral pulmonary nodules and mosaic attenuation on CT who had a diagnostic lung biopsy. A thoracic radiologist reviewed all CT scans. Chi-square test was used for categorical variables, and odds ratios were utilized to measure the association between certain variables and DIPNECH.

Results

Fifty-one patients met our inclusion criteria; 40 (78%) were females and 34 (67%) were never-smokers. Median age was 65 (interquartile range 55–73) years. Lung biopsy was surgical in 21 patients (41%), transbronchial in 17 (33%), and transthoracic in 12 (24%); explanted lungs were examined in 1 (2%). Metastatic/multifocal cancer was the most common diagnosis, and was found in 17 (33%) cases. Bronchiolitis was diagnosed in 12 patients (24%), interstitial lung disease in 10 (20%), and DIPNECH in 5 (10%). Previous diagnosis of an obstructive lung disease (odds ratio 15.8; P = 0.002), and peribronchial nodular distribution on CT (odds ratio 14.4; P = 0.006) were significantly correlated with DIPNECH. Although statistical significance was not reached, DIPNECH nodules were more likely to display solid attenuations (80% vs. 67%, P = 0.45), and were more numerous; > 10 nodules were seen in 80% of DIPNECH cases vs. 52% in others (P = 0.23). Because DIPNECH primarily affects women, we analyzed the women-only cohort and found similar results.

Conclusions

Various disorders can manifest the CT pattern of bilateral pulmonary nodules together with mosaic attenuation, and this combination is nonspecific for DIPNECH, which was found in only 10% of our cohort. Previous diagnosis of an obstructive lung disease, and peribronchial distribution of the nodules on CT increased the likelihood of DIPNECH vs. other diagnoses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02103-w.

A 75-Year-Old Woman With Pulmonary Nodules and Dyspnea

CASE PRESENTATION

A 75-year-old woman was referred to the pulmonary office in January 2020 for cough and progressive worsening of shortness of breath over the years. Her medical history was significant for asthma that was diagnosed approximately 10 years earlier, when she first developed dyspnea. A pre-bronchodilator spirometry at that time showed severe airflow obstruction (Fig 1). The patient was incidentally found to have several noncalcified pulmonary nodules on a chest CT scan in 2015, which was obtained as a part of dyspnea workup. She underwent bronchoscopic evaluation with transbronchial biopsy of the largest nodule (1.6 × 1.2 cm) in the right middle lobe. She was diagnosed with low-grade neuroendocrine tumor (typical carcinoid) and had been under surveillance without any progression in the number of nodules or the size of the existing nodules. She was a lifelong nonsmoker and no family history of asthma. Over the years, she received multiple courses of systemic corticosteroids and different inhalers, without any improvement in her symptoms. The patient was frustrated by the lack of perceived benefit, and she discontinued all respiratory medications. She denied any fever, night sweats, exertional chest pain, or seasonal allergies but reported cough, wheezing, and severe exertional shortness of breath. She was unable to walk more than 20 feet at a time. She had no pets at home and did not travel outside the United States. Her only home medications were multivitamins and low-dose aspirin.

Long-Term Imaging Follow-Up in DIPNECH: Multicenter Experience

Diffuse pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pre-invasive disease whose pathophysiology remains unclear. We aimed to assess long-term evolution in imaging of DIPNECH, in order to propose follow-up recommendations. Patients with histologically confirmed DIPNECH from four centers, evaluated between 2001 and 2020, were enrolled if they had at least two available chest computed tomography (CT) exams performed at least 24 months apart. CT exams were analyzed for the presence and the evolution of DIPNECH-related CT findings. Twenty-seven patients, mostly of female gender (n = 25/27; 93%) were included. Longitudinal follow-up over a median 63-month duration (IQR: 31–80 months) demonstrated an increase in the size of lung nodules in 19 patients (19/27, 70%) and the occurrence of metastatic spread in three patients (3/27, 11%). The metastatic spread was limited to mediastinal lymph nodes in one patient, whereas the other two patients had both lymph node and distant metastases. The mean time interval between baseline CT scan and metastatic spread was 70 months (14, 74 and 123 months). Therefore, long-term annual imaging follow-up of DIPNECH might be appropriate to encompass the heterogeneous longitudinal behavior of this disease.

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.

[Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia with tumorlet formation: A case report and review of the literature]

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia is an infrequent lesion recently classified by the WHO as preinvasive. It can present with the formation of tumorlets (neuroendocrine cell groups up to 5 mm) which result in a typical histological and radiological image. We report a case of a 67-year-old women who presented with a chronic cough. The CT scan showed bilateral minute, multiple pulmonary nodules. A biopsy revealed a diffuse idiopathic pulmonary neuroendocrine cell hyperplasia with several tumorlets. After two years of follow-up, imaging studies showed no significant changes.

An Update on the Management of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH)

OPINION STATEMENT

DIPNECH is caused by an idiopathic proliferation of pulmonary neuroendocrine cells which can lead to bronchiolitis and multifocal lung neuroendocrine tumors. Patients often present with chronic cough and dyspnea. Larger NETs may develop malignant potential. Somatostatin analogs can palliate chronic symptoms, particularly cough. Surgical resection can be considered for relatively large (e.g. >1 cm), progressive tumors.

[Lung imaging in severe asthma]

INTRODUCTION

Asthma is a common disease whose diagnosis does not typically rely on the results of imaging. However, chest CT has gained a key place over the last decade to support the management of patients with difficult to treat and severe asthma.

STATE OF THE ART

Bronchial wall thickening and mild dilatation or narrowing of bronchial lumen are frequently observed on chest CT in people with asthma. Bronchial wall thickening is correlated to the degree of obstruction and to bronchial wall remodeling and inflammation. Diverse conditions which can mimic asthma should be recognized on CT, including endobronchial tumours, interstitial pneumonias, bronchiectasis and bronchiolitis. Ground-glass opacities and consolidation may be related to transient eosinophilic infiltrates, infection or an associated disease (vasculitis, chronic eosinophilic pneumonia). Hyperdense mucous plugging is highly specific for allergic bronchopulmonary aspergillosis.

PERSPECTIVES

Airway morphometry, air trapping and quantitative analysis of ventilatory defects, with CT or MRI, can help to identify different morphological subgroups of patients with different functional or inflammatory characteristics. These imaging tools could emerge as new biomarkers for the evaluation of treatment response.

CONCLUSION

Chest CT is indicated in people with severe asthma to search for additional or alternative diagnoses. Quantitative imaging may contribute to phenotyping this patient group.

Constrictive bronchiolitis in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterised by multifocal proliferation of neuroendocrine cells and belongs in the spectrum of pulmonary neuroendocrine tumours. Some patients with DIPNECH develop airflow obstruction but the relationship between the two entities remains unclear.

Methods

We performed a computer-assisted search of the Mayo Clinic's electronic medical records for biopsy-proven cases of DIPNECH. We extracted clinical, pulmonary function, imaging and histopathological data along with treatments and outcomes.

Results

Among 44 patients with DIPNECH 91% were female and the median age was 65 years (interquartile range 56–69 years); 73% were never-smokers. Overall, 38 patients (86%) had respiratory symptoms including cough (68%) and dyspnoea (30%); 45% were previously diagnosed to have asthma or COPD. Pulmonary function testing showed an obstructive pattern in 52%, restrictive pattern in 11%, mixed pattern in 9%, nonspecific pattern in 23%, and was normal in 5%. On chest computed tomography scan, 95% manifested diffuse nodules and 77% manifested mosaic attenuation. For management, 25% of patients were observed without pharmacological therapy, 55% received an inhaled bronchodilator, 41% received an inhaled corticosteroid, 32% received octreotide; systemic steroids, azithromycin, or combination chemotherapy was employed in four patients (9%). Of 24 patients with available follow-up pulmonary function tests, 50% remained stable, 33% worsened and 17% improved over a median interval of 21.3 months (interquartile range 9.7–46.9 months).

Conclusion

DIPNECH occurs mostly in women and manifests diffuse pulmonary nodules and mosaic attenuation on imaging. It is commonly associated with airflow obstruction due to constrictive bronchiolitis, which manifests limited response to current pharmacological therapy.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is an under-recognised cause of obstructive lung disease in women. Constrictive bronchiolitis associated with DIPNECH manifests limited response to currently employed therapies.https://bit.ly/3c3RZoe

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: Imaging and Clinical Features of a Frequently Delayed Diagnosis

OBJECTIVE. The purpose of this study was to assess features of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) on CT, clinical presentation, and delays in radiologic and clinical diagnosis in a series of 32 patients. MATERIALS AND METHODS. Medical records of patients with DIPNECH from the years 2000-2017 were obtained from an institutional data warehouse. Inclusion criteria were an available CT examination and either a pathologic diagnosis of DIPNECH or pathologic findings of multiple carcinoid tumorlets or carcinoid tumor with CT features suggesting DIPNECH. Two thoracic radiologists with 10 and 14 years of experience reviewed CT examinations and scored cases in consensus. RESULTS. All 32 patients were women, and most had never smoked (69%). The mean age at presentation was 61 years. Symptoms included chronic cough (59%) or dyspnea (28%), and the initial clinical diagnosis was asthma in 41%. DIPNECH was clinically suspected at presentation in only one case and was mentioned by the interpreting radiologist in only 31% of cases. CT characteristics included numerous nodules with a lower zone and peribronchiolar predominance, mosaic attenuation, and nodular bronchial wall thickening. Number of nodules at least 5 mm in diameter showed strong inverse correlations with the percentage predicted for both forced vital capacity and forced expiratory volume in 1 second and a moderate inverse correlation with total lung capacity percentage predicted. In cases with a follow-up CT interval of 3 years or longer, 85% of patients showed an increase in size of the largest nodule, and 70% had an increase in size in multiple nodules. CONCLUSION. Many cases of DIPNECH are originally missed or misdiagnosed by radiologists and clinicians. Awareness of the typical clinical and imaging features of DIPNECH may prompt earlier diagnosis of this condition.

Primary lung neoplasms presenting as multiple synchronous lung nodules

Multiple synchronous lung nodules are frequently encountered on computed tomography (CT) scanning of the chest and are most commonly either non-neoplastic or metastases from a known primary malignancy. The finding may initiate a search for primary malignancy elsewhere in the body. An exception to this rule, however, is a class of rare primary lung neoplasms that originate from epithelial (pneumocytes and neuroendocrine), mesenchymal (vascular and meningothelial) and lymphoid tissues of the lung. While these rare neoplasms also present as multiple synchronous unilateral or bilateral lung nodules on chest CT, they are often overlooked in favour of more common causes of multiple lung nodules. The correct diagnosis may be suggested by a multidisciplinary team and established on biopsy, performed either as part of routine diagnostic work-up or staging for malignancy. In this review, we discuss clinical presentations, imaging features, pathology findings and subsequent management of these rare primary neoplasms of the lung.

Development and Validation of Diffuse Idiopathic Pulmonary Neuroendocrine Hyperplasia Diagnostic Criteria

Introduction

Diffuse idiopathic pulmonary neuroendocrine hyperplasia (DIPNECH) is a rare condition that is likely underdiagnosed owing to the lack of established and validated diagnostic criteria. These clinical guidelines are empirical and created on the basis of a limited number of studies. This study was designed to validate the existing criteria and to identify new clinical parameters that can accurately diagnose DIPNECH.

Methods

Patients with DIPNECH were identified from a cohort that underwent surgical lung resection for pulmonary carcinoids. The study cohort included a total of 105 consecutive cases with neuroendocrine lesions. Initial diagnostic predictors of DIPNECH were selected from the literature. We employed univariate and multivariate models to evaluate the association of clinical, pathologic, radiologic variables with the likelihood of DIPNECH.

Results

Univariate analysis identified age, sex, chronic obstructive pulmonary disease diagnosis, obstructive abnormalities, pulmonary nodules, mosaicism, absolute numbers of pulmonary neuroendocrine lesions (PNELs), and the number of tumorlets as significant DIPNECH predictors (for p < 0.05). After adjustment for sampling variations, the ratio of the total number of PNELs to the number of bronchioles was found to be considerably higher in DIPNECH category. Multivariate analysis identified the total number of PNELs and multiple pulmonary nodules (>10) as independent predictors of DIPNECH. The performance of our criteria revealed an accuracy of 76% in detecting DIPNECH cases.

Conclusions

We proposed a set of diagnostic criteria for DIPNECH on the basis of an expert-panel approach integrating pathological features, radiology, and clinical data. Our findings will help identify DIPNECH patients, without a pathological confirmation of a neuroendocrine lesion. Before the implementation of these criteria in clinical practice, they require further validation in multi-institutional cohorts.

Somatostatin Analogs Improve Respiratory Symptoms in Patients With Diffuse Idiopathic Neuroendocrine Cell Hyperplasia

BACKGROUND

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare lung disease associated with proliferation of neuroendocrine cells in the lung and multifocal neuroendocrine tumorlets/tumors. Although usually considered an indolent condition, DIPNECH causes chronic, progressive cough and dyspnea which can adversely impact quality of life. There is very limited information on the treatment of this condition. The objective of this study was to assess changes in symptoms and pulmonary function tests (PFTs) in response to somatostatin analog (SSA) treatment.

METHODS

Patients with clinical and/or pathologic diagnosis of DIPNECH and chronic respiratory symptoms were treated with SSAs at the H. Lee Moffitt Cancer Center and Research Institute, Hadassah-Hebrew University Medical Center, and Mayo Clinic Cancer Center. Their charts were reviewed to assess changes in symptoms and PFTs.

RESULTS

Forty-two patients were identified who had either chronic cough or dyspnea because of proven or suspected DIPNECH and who had received treatment with an SSA. Thirty-three patients experienced symptomatic improvement. Additionally, 14 of 15 patients in whom PFTs were checked were noted to have an improvement in FEV₁ after treatment.

CONCLUSIONS

SSA treatment can improve chronic respiratory symptoms and PFTs in patients with DIPNECH.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia in a young man with hypoxia: a case report and review of the literature

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare lung disease, which usually affects older women. This disease is often asymptomatic. For patients who are symptomatic, symptoms usually include cough and dyspnea. In this paper, we reported a 38-year-old man who suffered from chest pain for 3 months. CT scan findings revealed scattered nodules that were less than 1 cm. Spirometry was normal and the arterial oxygen saturation at room air was 85%. Open lung biopsy revealed DIPNECH. Patients with DIPNECH are mainly elderly women with symptoms including cough and dyspnea. However, we reported a young man with chest pain and hypoxia without dyspnea. DIPNECH can occur in male and female individuals at any age. (www.actabiomedica.it)

Epithelial cell plasticity defines heterogeneity in lung cancer

Lung cancer is the leading cause of cancer death for both men and women and accounts for almost 18.4% of all deaths due to cancer worldwide, with the global incidence increasing by approximately 0.5% per year. Lung cancer is regarded as a devastating type of cancer owing to its high prevalence, reduction in the health-related quality of life, frequently delayed diagnosis, low response rate, high toxicity, and resistance to available therapeutic options. The highly heterogeneous nature of this cancer with a proximal-to-distal distribution throughout the respiratory tract dramatically affects its diagnostic and therapeutic management. The diverse composition and plasticity of lung epithelial cells across the respiratory tract are regarded as significant factors underlying lung cancer heterogeneity. Therefore, definitions of the cells of origin for different types of lung cancer are urgently needed to understand lung cancer biology and to achieve early diagnosis and develop cell-targeted therapies. In the present review, we will discuss the current understanding of the cellular and molecular alterations in distinct lung epithelial cells that result in each type of lung cancer.

Pulmonary Fibrosis in Children

Pulmonary fibrosis (PF) is a very rare condition in children, which may be observed in specific forms of interstitial lung disease. None of the clinical, radiological, or histological descriptions used for PF diagnosis in adult patients, especially in situations of idiopathic PF, can apply to pediatric situations. This observation supports the view that PF expression may differ with age and, most likely, may cover distinct entities. The present review aims at summarizing the current understanding of PF pathophysiology in children and identifying suitable diagnostic criteria.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) with liver metastases

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) is a rare pulmonary disorder characterised by classic radiological findings and symptoms of obstructive lung disease. DIPNECH is considered a precursor to carcinoid tumours in the lungs. In this case, we describe a patient with years of unexplained dry cough presenting with 2 weeks of progressive nausea and vomiting, and found to have massive hepatomegaly on examination. By CT-PE, she was diagnosed with DIPNECH, and abdominal MRI revealed metastatic carcinoid tumours. Despite its non-specific presentation, DIPNECH has characteristic radiological findings of mosaic attenuation with numerous pulmonary nodules. DIPNECH requires early identification and close surveillance to prevent progression to carcinoid tumours. Thus, it is critical for frontline providers to consider this diagnosis as part of their differential when other common causes of obstructive lung disease have been ruled out.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Case series and a review of the literature

RATIONALE

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare idiopathic disease with only about 100 cases reported in the literature.

PATIENT CONCERNS

Here, we presented 4 cases of DIPNECH. Four patients included 2 females and 2 males, aged 54 to 64 years old; 3 had no smoking history and 1 had history of smoking for 30 years. Surgical resection was performed for every patient. Cases 1 and 3 did not receive postoperative chemotherapy or radiotherapy, and case 2 received 4 times of postoperative chemotherapy. Case 4 just finished the operation and after a period of time, he will receive postoperative chemotherapy.

DIAGNOSES

Case 1: A 57-year-old female had chest pain, and computer tomography (CT) examination prompted a mass shadow of left lung lower lobe. Case 2: A 64-year-old female had cough and expectoration for more than 1 month. CT examination showed: a lump with diameter of about 2.5 cm and irregular edge was in right lung upper lobe, being largely possibly lung cancer. Case 3: A 54-year-old male, CT examination accidentally found a long strip-shaped nodule in left lung oblique fissure when checkup's, and he had no fever, cough, expectoration, chest tightness, or chest pain. Case 4: A 61-year-old male, checkup's CT examination accidentally found a nodule, fibrosis, bronchiectasis, and secondary infection in the left lower lobe. Combined with pathological morphology and immunohistochemistry, cases 1 and 3 were diagnosed as DIPNECH with multiple carcinoid tumorlet formation and chronic inflammation and bronchiectasis, case 2 was diagnosed as an adenocarcinoma with DIPNECH and multiple carcinoid tumorlet formation, case 4 was diagnosed as an adenocarcinoma with DIPNECH and multiple carcinoid tumorlet formation and chronic inflammation and bronchiectasis.

INTERVENTIONS

Surgical resection was performed for every patient. Cases 1 and 3 did not receive postoperative chemotherapy or radiotherapy, and case 2 received 4 times of postoperative chemotherapy. Case 4 just finished the operation and after a period of time, he will receive postoperative chemotherapy.

OUTCOMES

Four patients have been followed up and have had good condition.

LESSONS

DIPNECH is often found accidentally in a surgical specimen, is easily missed, and needs careful observation. Immunohistochemistry is necessary to make this diagnosis.

Diffuse idiopathic neuroendocrine cell hyperplasia as a rare cause of chronic cough

A 39-year-old Caucasian woman, who has never smoked, presented a 16-year-duration chronic dry cough. She was prescribed by her general physician with corticosteroid and long-acting β-agonist inhalers assuming it was asthma, with mild symptomatic improvement. When cough got more persistent and associated with exertional dyspnoea and wheezing, a chest CT scan was performed, which showed multiple bilateral micronodular formations and diffuse mosaic lung pattern with air trapping. She was sent to our Respiratory Department and performed a bronchoalveolar lavage and cryobiopsy that were inconclusive. She underwent surgical lung biopsy with pathology revealing multiple foci of neuroendocrine cell hyperplasia and tumourlets associated with constrictive bronchiolitis, a histological pattern suggestive of diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH). DIPNECH is a rare and preinvasive disease. Presenting symptoms can be cough and breathlessness. At the time of writing, the patient is on octreotide with symptomatic improvement.

Evaluation of the Prognostic Significance of TNM Staging Guidelines in Lung Carcinoid Tumors

INTRODUCTION

The TNM classification for lung cancer, originally designed for NSCLC, is applied to staging of bronchopulmonary carcinoid tumors. The validity of the eighth edition of the staging system for carcinoid tumors has not been assessed. In this study, we evaluated its prognostic accuracy by using data from a large national population-based cancer registry.

METHODS

Patients with typical and atypical bronchopulmonary carcinoids diagnosed between 2000 and 2013 were identified from the National Cancer Institute's Surveillance, Epidemiology and End Results registry. We used competing risks analysis to compare 10-year disease-specific survival (DSS) across stages.

RESULTS

Overall, 4645 patients with bronchopulmonary carcinoid tumors were identified. Worsening DSS with increasing TNM status and stage was demonstrated across both typical and atypical carcinoids, with overlaps between adjacent subcategories. The combined stages (I versus II, II versus III, and III versus IV) showed greater separation in DSS despite persistent overlaps between groups. For typical carcinoids, we found decreased DSS for stages II, III, and IV, with hazard ratios of 3.8 (95% confidence interval [CI]: 2.6-5.6), 4.3 (95% CI: 3.0-6.1), and 9.0 (95% CI: 6.1-13.1), respectively, compared with stage I.

CONCLUSION

The combined stage categories of the eighth edition of the TNM staging system provide useful information on outcomes for typical and atypical carcinoids. However, persistent overlaps in combined stage and subcategories of the staging system limit the usefulness of the TNM staging system, particularly in intermediate stages. These limitations suggest the need for future further study and refinement.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: Report of two cases

INTRODUCTION

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare disorder characterized by a proliferation of neuroendocrine cells within the lung. It is classically described as a disease with persistent cough, dyspnea and wheezing in non-smoker middle aged females. CT of the chest reveals diffuse air trapping with mosaic pattern.

PATIENTS AND METHODS

We present two cases of DIPNECH that were sent to our department to perform a lung biopsy with the diagnostic suspicion of diffuse interstitial disease. Both cases were women with a history of chronic cough and moderate effort dyspnea.

RESULTS AND DISCUSSION

The aim of this paper is that physicians take into account this diagnostic entity before treating as an asthmatic a patient with these characteristics, not forgetting that they are prenoplastic lesions.

Series of rare lung diseases mimicking imaging patterns of common diffuse parenchymal lung diseases

Diffuse parenchymal lung diseases (DPLDs) encompass a variety of restrictive and obstructive lung pathologies. In this article, the authors discuss a series of rare pulmonary entities and their high-resolution computed tomography imaging appearances, which can mimic more commonly encountered patterns of DPLDs. These cases highlight the importance of surgical lung biopsies in patients with imaging findings that do not show typical imaging features of usual interstitial pneumonia.

A Rare Case of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia

We describe the case of a 53-year-old woman who visited many pneumologists without a diagnosis until finally being diagnosed with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). It is a relatively new disease characterized by neuroendocrine cell hyperplasia in small airways. She has stable DIPNECH and neuroendocrine carcinoma with somatostatin therapy.

Persistent Lung Disease in Adults with NKX2.1 Mutation and Familial Neuroendocrine Cell Hyperplasia of Infancy

RATIONALE

Neuroendocrine cell hyperplasia of infancy (NEHI) is a diffuse lung disease that presents in infancy and improves during childhood. Long-term outcomes have not previously been described. In one familial cohort, we have reported that NEHI is associated with a heterozygous variant of NKX2.1/TTF1.

OBJECTIVES

Our objective was to determine whether pulmonary abnormalities persist in adults with NEHI, to aid in elucidating the natural history of this disease.

METHODS

Four adult relatives with heterozygous NKX2.1 mutation and with clinical histories compatible with NEHI enrolled in a prospective study that included questionnaires, pulmonary function tests, and chest computed tomography scans.

MEASUREMENTS AND MAIN RESULTS

Mild radiologic abnormalities including mosaicism were seen in all four cases. Three individuals had obstruction on pulmonary function tests, two had marked air trapping, and three had symptomatic impairments with exercise intolerance.

CONCLUSIONS

Although clinical improvement occurs over time, NEHI may result in lifelong pulmonary abnormalities in some cases. Further studies are required to better describe the natural history of this disease and would be facilitated by additional delineation of genetic mechanisms to enable improved case identification.

Pulmonary Neuroendocrine Cell Hyperplasia Associated with Surfactant Protein C Gene Mutation

Familial interstitial lung disease (ILD) is defined as presence of ILD in 2 or more family members. Surfactant protein C (SFTPC) gene mutations are rare, but well-known cause of familial ILD. We reported a 20-year-old male, who was referred for lung transplantation. He was symptomatic at age 3 and underwent surgical lung biopsy at age 6, which revealed a nonspecific interstitial pneumonia (NSIP) pattern. Genetic workup revealed a novel SFTPC mutation in the first intron with a C to A transversion. At age 21, he underwent bilateral lung transplantation. Explanted lung histology suggested NSIP. In addition there was pulmonary neuroendocrine cell (PNEC) hyperplasia and carcinoid tumorlets. His mother had undergone lung transplantation several years earlier, and her explanted lung showed similar pathology. SFTPC mutations are inherited in an autosomal dominant pattern. Various types of ILD have been associated with SFTPC mutation including NSIP, usual interstitial pneumonia (UIP), and desquamative interstitial pneumonia (DIP). PNEC hyperplasia has been described to occur in association with lung inflammation but has not been previously described with familial ILD associated with SFTPC mutation.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia diagnosed by tranbronchoscopic cryoprobe biopsy technique

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) remains a poorly understood clinical entity. It is currently classified as a premalignant condition by the World Health Organization (WHO). Symptoms are similar to those associated with obstructive lung disease, including breathlessness and cough. The presentation is often initially ascribed to other diseases such as asthma or chronic obstructive pulmonary disease. Here, we present what we believe is the first described case of DIPNECH diagnosed by transbronchoscopic cryoprobe biopsy. The patient presented with chronic cough, dyspnoea, pulmonary function tests consistent with obstruction, and a computed tomography (CT) scan of chest with multiple nodules. The patient went on to have transbronchoscopic cryoprobe biopsies of the lung, which confirmed the diagnosis of DIPNECH.

Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia: A Case Report and Review of the Literature

Patient: Female, 69

Final Diagnosis: Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Symptoms: Occasional and mild shortness of breath • persistent nocturnal cough

Medication: —

Clinical Procedure: Surgical intervention: right middle lobectomy

Specialty: Surgery

Ten Years of Chronic Cough in a 64-Year-Old Man With Multiple Pulmonary Nodules

A 64-year-old male former smoker with a history of prostate cancer presented to our pulmonary clinic, complaining of nonproductive cough for 10 years. Prior evaluation included treatment for upper airway cough syndrome and gastroesophageal reflux, stopping angiotensin-converting enzyme inhibitor, and initiation of inhaled β-agonists. Esophageal pH monitoring indicated silent reflux, and proton pump inhibitor therapy was started. He continued to cough and complain of dyspnea. Physical examination produced unremarkable results, with no evidence of lymphadenopathy. Pulmonary function tests showed a pseudo-restrictive pattern with air trapping, hyperreactivity, and incomplete bronchodilator responsiveness: FEV1, 2.48 L (69% of predicted); FVC, 3.57 L (75% of predicted); FEV1/FVC, 92%; total lung capacity, 7.00 L (100% of predicted); and residual volume, 3.05 L (136% of predicted). Laboratory studies, including a complete metabolic panel, prostate-specific antigen test, and complete blood count, yielded normal results.

Case of sclerosing pneumocytoma combined with a typical carcinoid and pulmonary adenocarcinoma in different lobes

We report the first case of a 62‐year‐old man with a sclerosing pneumocytoma (SP) combined with a typical carcinoid (TC) and pulmonary adenocarcinoma in different lung lobes. Computed tomography revealed two nodules. The radiological diagnosis was primary lung cancer and a metastatic nodule; however, no enlarged lymph nodes were observed. Histological and immunohistochemical analyses defined the 1.7 cm nodule in the right upper lobe as adenocarcinoma and the 1.3 cm nodule in the left lower lobe as SP combined with TC. This case is noteworthy because of the rarity of SP combined with TC, the comprehensive examination of frozen and permanent sections, and the clinical implications of the differential diagnosis of lung nodules.

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.

Diffuse Neuroendocrine Cell Hyperplasia: Report of Two Cases

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary disorder characterised by a proliferation of neuroendocrine cells within the lung. It is believed that a minority of the patients with DIPNECH can develop carcinoid tumors. Here, we report two new cases of DIPNECH with coexisting carcinoid tumors.

Pulmonary Neuroendocrine Tumors: Part I. Spectrum and Characteristics of Tumors

Pulmonary neuroendocrine tumors arise from Kulchitzky cells of the bronchial mucosa and include typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell lung cancer. These tumors have a variable growth rate that determines their presentation and prognosis. Typical carcinoid has the lowest growth rate and better prognosis; in contrast, small cell lung cancer is an aggressive tumor with a very poor prognosis. Although there are some overlapping histologic features between these tumors, clinical, imaging, and immunohistochemical markers are useful in the differentiation of pulmonary neuroendocrine tumors. The treatment options differ on the basis of histologic characteristics. In this article, we aim to describe the spectrum of neuroendocrine tumors of the lung, except for small cell lung cancer, and their clinical, pathologic, and imaging findings, with a focus on treatment options.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome

The term diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) may be used to describe a clinico-pathological syndrome, as well as an incidental finding on histological examination, although there are obvious differences between these two scenarios. According to the World Health Organization, the definition of DIPNECH is purely histological. However, DIPNECH encompasses symptomatic patients with airway disease, as well as asymptomatic patients with neuroendocrine cell hyperplasia associated with multiple tumourlets/carcinoid tumours. DIPNECH is also considered a pre-neoplastic lesion in the spectrum of pulmonary neuroendocrine tumours, because it is commonly found in patients with peripheral carcinoid tumours.

In this review, we summarise clinical, physiological, radiological and histological features of DIPNECH and critically discuss recently proposed diagnostic criteria. In addition, we propose that the term “DIPNECH syndrome” be used to indicate a sufficiently distinct patient subgroup characterised by respiratory symptoms, airflow obstruction, mosaic attenuation with air trapping on chest imaging and constrictive obliterative bronchiolitis, often with nodular proliferation of neuroendocrine cells with/without tumourlets/carcinoid tumours on histology. Surgical lung biopsy is the diagnostic gold standard. However, in the appropriate clinical and radiological setting, transbronchial lung biopsy may also allow a confident diagnosis of DIPNECH syndrome.