Pulmonary Neuroendocrine Cell Hyperplasia Research Articles

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia in adults

Diffuse Idiopathic Pulmonary NeuroEndocrine Cell Hyperplasia (DIPNECH) is an understudied rare disease that should be taken into account in the differential diagnosis of therapy-resistant bronchial obstruction combined with focal pulmonary lesions and mosaic attenuation on chest CT. The aim of this article is to discuss the aspects of clinical and morphological diagnosis, therapeutic options, prognosis assessment, and the need for follow-up using a clinical case as an example. The article describes a clinical case of DIPNECH in a 55-year-old woman, and also provides a brief review of the scientific literature on DIPNECH. DIPNECH is a rare disease that most often affects non-smoking women aged around 60 years. The most frequent clinical manifestations are cough, dyspnea, stridor, and broncho-obstructive syndrome. Only histological and immunohistochemical assays can confirm the diagnosis. DIPNECH should be considered as part of the differential diagnosis in patients with prolonged cough, dyspnea of unclear genesis and changes on chest CT in the form of pulmonary focal lesions and mosaic attenuation. Conclusion. The presented clinical case shows the challenges and importance of timely diagnosis.

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

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. 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. 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. 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.

Congenital Pulmonary Airway Malformation Type 1 with Pulmonary Neuroendocrine Cell Hyperplasia in an Adult Male: a Rare Case Report

Abstract Introduction/Objective Congenital pulmonary airway malformations (CPAM) is rare, usually diagnosed in the pediatric population, and may occur in adults. Pulmonary neuroendocrine cell hyperplasia (PNECH) mimicking diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) associated with CPAM has not been described previously. We report a case of CPAM Type 1 with PNECH. Methods/Case Report A 33-year-old male, with past medical history of latent tuberculosis (TB) by Quantiferon blood testing, recurrent pneumonia, recurrent lung abscesses, and lung cavitary lesion for three years, presented with fever, cough with hemoptysis, shortness of breath, and left-sided chest pain. Computerized tomography of chest displayed a 10.8 cm cavitary lesion in the left lower lobe of the lung. The patient underwent left lower lobectomy of the lung. Grossly, the lobectomy specimen revealed a 10.5 cm irregular cavity communicating to the superior segmental bronchus of the left lower lobe. Microscopically, the dominant large cyst was surrounded by lung parenchyma and small cystically dilated spaces resembling bronchioles under the fibrotic pleura. The large cyst was lined by respiratory epithelium with rare pathognomonic mucous cells in clusters. Cyst walls contained smooth muscle, small islands of cartilage, and focal intense acute and chronic inflammatory cell infiltrates with hemorrhage. There were multiple foci of proliferation of pulmonary neuroendocrine cells centered around bronchioles surrounding the large cyst. The neuroendocrine cells were arranged from individual cells and cellular aggregates to larger tumorlets, highlighted by Synaptophysin and Chromogranin immunostains. No granuloma or necrosis was present. No acid-fast bacilli or fungal microorganisms were identified by special stains. The findings are consistent with CPAM type 1, with PNECH. Results (if a Case Study enter NA) NA Conclusion Our study demonstrates a histologically diagnosed adult congenital pulmonary airway malformations type 1 with an incidental pulmonary neuroendocrine cell hyperplasia, which mimics diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. To the best of our knowledge, this is the first report of such an association.

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

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. 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. 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. 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.

Precursor lesions of lung tumors

Lung cancer is the leading cause of cancer deaths globally with many new cases diagnosed each year. Recent studies have shown that an accumulation of various genetic abnormalities results in progressive morphologic changes in bronchial epithelium. Such changes are part of the continuum from precursor lesions to invasive lung cancers. Improvement in diagnostic modalities has made the detection of such preneoplastic lesions possible and resection at this stage confer excellent prognosis. The World Health Organization (WHO) has recognized atypical adenomatous hyperplasia/ adenocarcinoma in situ, squamous dysplasia/ squamous cell carcinoma in situ, and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia as the precursor lesions of adenocarcinoma, squamous cell carcinoma, and carcinoid tumors respectively. This review summarizes the key features of these preneoplastic lesions based on the current understanding and knowledge.

DIPNECH: pragmatic approach, uncertainties, notable associations, and a proposal for an improved definition.

DIPNECH is an increasingly recognized entity that primarily affects middle-aged and elderly women. It is characterized by abnormal proliferation of pulmonary neuroendocrine cells (PNECs) and considered a preinvasive lesion for carcinoid tumorlets/tumors. Sometimes, DIPNECH is accompanied by constrictive bronchiolitis which usually manifests as chronic cough and/or dyspnea, along with airflow limitation on spirometry. The telltale imaging sign of DIPNECH is the presence of multiple noncalcified pulmonary nodules and mosaic attenuation on CT. However, these clinico-radiologic features of DIPNECH are characteristic but nonspecific; thus, histopathologic confirmation is usually necessary. DIPNECH has an indolent course, and only rarely leads to respiratory failure or death; progression to overt neuroendocrine tumor (carcinoid) of the lung occurs in a minority of patients. Of available therapies, somatostatin analogs and mTOR inhibitors are most promising. In this review, we provide an update regarding the diagnosis and management of DIPNECH and describe critical gaps in our understanding of this entity, including the central terms "diffuse" and "idiopathic". We also summarize the inconsistencies in definitions employed by recent studies and discuss the pitfalls of the DIPNECH definitions proposed by the World Health Organization in 2021. In this context, we propose an objective and reproducible radio-pathologic case definition intended for implementation in the research realm and seeks to enhance homogeneity across cohorts. Furthermore, we discuss aspects of PNECs biology which suggest that PNEC hyperplasia may contribute to the pathogenesis of phenotypes of lung disease aside from constrictive bronchiolitis and carcinoid tumorlets/tumors. Finally, we steer attention to some of the most pressing and impactful research questions awaiting to be unraveled.

(857) Bilateral Lung Transplant with Recognition of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) of rhe Donor Lungs in the Immediate Postoperative Period

(857) Bilateral Lung Transplant with Recognition of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH) of rhe Donor Lungs in the Immediate Postoperative Period

Pulmonary Function Tests as a Biomarker in Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia Patients Treated With Somatostatin Analogues.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) describes an indolent, under-recognised and poorly understood pulmonary condition with fewer than 200 reported cases across the literature. Currently, cases are diagnosed following a biopsy of the primary lesion, with treatment options centring on symptomatic benefit as opposed to targeting the underlying aetiology. Classically, DIPNECH lesions have been described as slow growing and benign, but with growing awareness of the condition, reports of metastatic disease with significant symptomatic burden have been reported. However, effectively addressing the subset of DIPNECH patients with greater metastatic potential remains an unmet clinical need. Due to the similarities between DIPNECH and carcinoid patients, several centres have considered using somatostatin analogues to not only help symptomatically but also to initiate tumour regression. However, to date, there are limited biomarkers to help evaluate the benefit of such options. In this review, we consider the use of pulmonary function tests (PFTs) to help quantify the benefit of somatostatin analogues. Although much of the evidence stems from small single-centre studies, the use of PFTs within the treatment pathway for both localised and metastatic DIPNECH represents a meaningful improvement from subjective monitoring of disease.

Plasma Progastrin-Releasing Peptide and Chromogranin A Assays for Diagnosing and Monitoring Lung Well-Differentiated Neuroendocrine Tumors: A Brief Report

IntroductionThe use of chromogranin A (CGA) as a circulating biomarker in lung carcinoids (LCs) is limited by low specificity and sensitivity. This study aimed to evaluate plasma progastrin-releasing peptide (ProGRPp) as an alternative to plasma CGA (CGAp), for the diagnosis and follow-up of LC. MethodsProGRPp and CGAp concentrations were measured in 107 patients with LC and 105 patients with benign lung disease (BLD). ResultsProGRPp distinguished patients with LC with active disease in the pretreatment (n = 43) and post-treatment (n = 43) groups from those with BLD: area under the curve for both 0.864 (p < 0.0001); sensitivity 67.4% and 58.1%, respectively; specificity 96.2%; at 64 pg/mL cutoff. CGAp failed to differentiate both LC groups from those with BLD: area under the curve 0.579 and 0.526 (for both p > 0.1); sensitivity 34.9% and 25.6%, respectively; specificity 73.3%; at 104 ng/mL cutoff. Only ProGRPp correlated with the Ki67 proliferation index (r = 0.40, p < 0.001) and was associated with mitotic count (p = 0.025), stage (p = 0.018), grade (p = 0.019), and the expression of thyroid transcription factor-1 (p = 0.005). ProGRPp had a high sensitivity (92.3%) in LC with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. Abnormal postoperative ProGRPp level was associated with residual disease (p = 0.029). The changes in ProGRPp level during treatment, a decrease greater than 30% and an increase greater than 8%, were associated with image-based outcomes, partial response and disease progression, respectively (p < 0.0001). CGAp did not reflect the disease course. ConclusionsProGRPp was superior to CGAp in diagnosing LC with correlations concerning proliferation, grading, staging, diffuse idiopathic pulmonary neuroendocrine cell hyperplasia co-occurrence, and response to treatment. ProGRPp is an optimal emerging biomarker to be further evaluated.

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

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. 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. 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 &lt; 0.001, &lt;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). Quantitative CT airway analysis in patients with DIPNECH demonstrates increased airway wall thickness and airway:artery ratio compared to controls. Quantitative CT measurement of airway wall thickening offers a potential imaging biomarker for treatment response.

A multidisciplinary approach to the work up and management of pulmonary carcinoid tumors and DIPNECH: a narrative review

Low and intermediate grade neuroendocrine tumors of the lung are uncommon malignancies representing 2% of all lung cancers. These are termed typical and atypical pulmonary carcinoid tumors. These can arise in the setting of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). The presentation, workup, management and outcomes of patients with these tumors can overlap with more common lung cancers but differ in that many of these patients have a prolonged clinical course. The objective of this narrative review is to summarize the literature and provide evidence and expert-based algorithms for work up and treatment of pulmonary carcinoids and DIPNECH. A search of PubMed and Web of Science databases ending April 15, 2022, with the following keywords "lung carcinoid", "DIPNECH", "lung neuroendocrine," and "bronchopulmonary carcinoid". Pulmonary carcinoid tumors benefit from a multidisciplinary approach. Pre-treatment imaging with contrast-enhanced computed tomography, and DOTATATE positron emission tomography is required. Surgical resection is the gold standard for curative intent, and possibly including sublobar resections. Patients can recur or develop new primaries thus emphasizing the importance of surveillance; national guidelines recommend at least a 10-year follow up. A growing body of literature support the use of endobronchial therapy, with long responses documented. Systemic therapy consists of everolimus, somatostatin analogs, peptide receptor radionuclide therapy, and chemotherapy. Diffuse idiopathic pulmonary neuroendocrine tumor cell hyperplasia is rare, but series suggest somatostatin analogs may confer clinical benefit. Pulmonary carcinoid tumors and DIPNECH are rare. Despite lack of regulatory approvals for advanced disease, multiple options are available but should be sequenced according to the clinical status and disease biology. Each patient should be discussed in a multidisciplinary setting and clinical trials should be considered if available.

Interstitial Lung Disease in Children: "Specific Conditions of Undefined Etiology" Becoming Clearer.

Children's interstitial lung disease (chILD) is a rare group of pediatric lung diseases affecting the lung interstitium diffusely. In this work, we focused our attention on a specific infant group of chILD, also known as "specific conditions of undefined aetiology", including pulmonary interstitial glycogenosis (PIG) and neuroendocrine cell hyperplasia of infancy (NEHI). PubMed was searched to conduct this narrative review. We searched for articles in English using the following keywords: (1) neuroendocrine cell hyperplasia of infancy; (2) NEHI; (3) pulmonary interstitial glycogenosis; (4) PIG; (5) chILD. An increasing interest and insight into these two conditions have been reported. The updated literature suggests that it is possible to look at these disorders as a continuum of diseases, rather than two different entities, since they share a pulmonary dysmaturity. NEHI and PIG are featured by dysmaturity of airway development and consequent respiratory distress. Understanding the underlying pathogenic mechanisms would lead to identifying new targeted therapies to ameliorate the mortality and morbidity of these rare conditions.

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) is considered to be a rare condition associated with lung neuroendocrine tumours (NET), and its natural history is poorly described. We aimed to assess the prevalence and clinicopathologic characteristics of DIPNECH in the lung NET population, and to investigate predictors of time-to-progression (TTP) and overall survival (OS). We retrospectively identified patients diagnosed with DIPNECH between April 2005 and December 2020. Clinical data were collected from medical records. The relationship between baseline characteristics and TTP and OS was analysed using the Kaplan-Meier method. Univariate analysis was performed using the Cox proportional hazards model. Of 311 patients with well-differentiated lung NETs, 61 (20%) had DIPNECH and were included in the study. Baseline demographics described 95% female, 59% never smokers and mean body mass index 34.4 kg m-2 ; 77% were typical carcinoids (TC), 13% atypical carcinoids (AC), and 10% both TC and AC (multicentric). At presentation, 54% of patients were asymptomatic. Multicentric NETs were demonstrated in 16 (26%) on histopathology, and a further 32 (52%) had synchronous NETs suggested on imaging (multiple nodules ≥ 5 mm). Seven (11%) patients developed metastases and the median OS from time of first metastasis was 37 months. AC histopathology and NET TNM stage ≥ IIA were associated with poorer TTP and OS. Of the DIPNECH cohort, the 15-year survival rate was 86%. DIPNECH may be more prevalent in the lung NET population than previously appreciated, especially in women. Although our results confirm that DIPNECH is predominantly an indolent disease associated with TC, 23% developed AC and these patients may warrant closer observation.

Multifocal bronchial neuroendocrine tumor (bNET): A new clinical entity.

9135 Background: Bronchial carcinoid (BC) is often categorized into multifocal (MBC) or solitary (SBC). MBC, excluding tumorlet and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, is considered a relatively uncommon subgroup of BC, with much of the MBC literature stemming from case reports/small series. Our study analyzes MBC among a large cohort of 569 patients with BC and argues for change to the current clinical understanding of MBC. We suggest using the term bronchial neuroendocrine tumor (bNET) to more accurately represent its cells of origin and move away from “carcinoid” (historically meaning “carcinoma-like”) and the outdated associated connotation that carcinoids all have a similar, benign clinical and biological behavior. Methods: Using the Mayo Clinic Epidemiology and Genetics of Lung Cancer Database with Institutional Review Board approval, we retrospectively reviewed 569 patients with bNET (204 males, 365 females) presenting to Mayo Clinic Rochester between 1/1997-12/2012. We used univariate and multivariate Cox regression analyses to evaluate factors affecting overall survival. Results: 80 patients (of 569, 14.1%) were diagnosed with multifocal (MbNET) and 489 with solitary (SbNET). Two-sided Fisher’s exact tests found that older age, female gender, never having smoked cigarettes, and tumorlets were associated with MbNET diagnosis. Family lung cancer history, histopathologic grading (pathology: typical vs. atypical), Ki67, and presence of syndromes (carcinoid, Cushing, and MEN1 syndromes) were similar between MbNET and SbNET groups. Most MbNET cases were stage III-IV at the time of diagnosis, while the majority of SbNET cases were stage I. 5-year OS (83%) and 5-year PFS (75%) of MbNET patients were higher than those of their SbNET counterparts (74% and 68%, respectively). Metastasis status was an independent prognostic factor of poor OS in SbNET (P&lt;0.001) but not in MbNET (P=0.71)(Table). Conclusions: Clinical, radiologic, and histopathologic characteristics and prognostic factors differed between SbNET and MbNET. MbNET arose as a new entity often with advanced stage disease, but good prognosis, which does not follow the NSCLC TNM staging system as in the 2009 NCCN guidelines (used during this study) or the updated 2021 NCCN guidelines which continue to stage lung carcinoid similarly to NSCLC. It may be beneficial to consider multifocal lung carcinoid instead as multifocal bNET, a new clinical entity, warranting a novel staging approach that more accurately reflects prognosis.[Table: see text]

March 2022 Medical Image of the Month: Pulmonary Nodules in the Setting of Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH)

No abstract available. Article truncated after 150 words. A 62-year-old woman presented to an outside hospital with chronic cough, prompting a CXR. Findings further prompted unenhanced chest CT to evaluate possible pulmonary nodules. The CT demonstrated multiple scattered, solid and centrilobular pulmonary nodules, most of which were small but there were two &gt;1 cm nodules, one in the right upper lobe (RUL) and a second in the lingula (Figure 1A,B). A subsequent FDG PET-CT was performed demonstrating increased metabolic activity in the RUL nodule with no activity in the lingular nodule (Figure 1C,D). Biopsy of the RUL nodule was consistent with a carcinoid. At this point the patient was referred to our center for further management. A repeat chest CT failed to demonstrate any significant change in the nodules. MIP and MinIP reconstructions from that examination demonstrate multiple small, solid pulmonary nodules (arrows) (Figure 2A), many of which were associated with air-trapping resulting in pulmonary mosaicism (circled) (Figure …

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: A rare and under-diagnosed condition

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: A rare and under-diagnosed condition

Incidental finding of pulmonary tumorlet in a case of surgically treated bronchiectatic cavity superimposed by aspergilloma

Introduction. Intracavitary aspergilloma is the consequence of a saprophytic infection of the lung with cavitary disease. Pulmonary tumorlet are nodular proliferations of the neuroendocrine cells less than 5 mm in diameter. Both aspergilloma in the bronchiectatic cavity of the lung and pulmonary tumorlet has rare been seen. Case outline. We present a 71-year-old woman with a medical history of recurrent pneumonia complicated with cough and hemoptysis. Computed tomography (CT) scan of the chest showed pulmonary soft tissue mass in the right lower lobe of the lung 42 ? 50 mm in diameter. Direct microscopy of the specimens of bronchioalveolar lavage showed spores of Aspergillus. Galactoman Ag test was also positive. Right lower lobectomy and mediastinal lymph node sampling was performed via thoracotomy. Pathohistological findings showed aspergilloma with the presence of pulmonary tumourlet and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) in the lymphovascular spaces. Five years follow up showed no abnormalities on the CT scan, and the patient remained alive without medical problems. Conclusion. The concomitant occurrence of bronchiectasis, aspergilloma, and precancerous lesions such as pulmonary tumourlet and DIPNECH is rare and further increases the risk of developing malignant tumors as well as recurrent infections. Therefore, surgical treatment can prevent the development of premalignant lesions and the occurrence of recurrent infections accompanied by dyspnea and hemoptysis as the main symptoms. The question of the connection between pulmonary tumourlet and chronic inflammatory lung diseases is raised. We hope that future researches will provide answers to this question.

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

BackgroundDiffuse 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.MethodsWe 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.ResultsFifty-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.ConclusionsVarious 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.

DIFFUSE IDIOPATHIC PULMONARY NEUROENDOCRINE HYPERPLASIA IN A PATIENT WITH MYCOBACTERIUM AVIUM COMPLEX

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: Diffuse idiopathic pulmonary neuroendocrine hyperplasia (DIPNECH) is a preneoplastic lesion that can progress to carcinoid tumors. It differs from reactive hyperplasia in its expression of tumor antigens such as Ki67 as well as the possibility of progression to carcinoid tumors. We present a case of an elderly female with a dry cough who was found to have a lung nodule showing granulomatous inflammation and a focus of neuroendocrine cell hyperplasia suggesting DIPNECH. CASE PRESENTATION: A 78-year-old female with a history of rheumatoid arthritis, breast cancer post excision and radiation therapy, presented with dry cough for a few months. She had a ten-pack-year history of smoking and quit eight years ago. She denied fevers, chills, night sweats, or acute weight changes. Chest CT and PET scan revealed a right middle lobe (RML) lung nodule with increased metabolic activity. EBUS and bronchoscopy specimens did not reveal any organisms or abnormal cytology. The patient underwent wedge resection of the RML. Pathology revealed extensive chronic inflammatory infiltrate with necrotizing granulomas and sparse foreign body giant cells, and a focus of bland appearing cells that stained positive for chromogranin and synaptophysin indicating neuroendocrine differentiation. MiB-1 proliferation index was 1%. Tissue culture grew MAC. A diagnosis of DIPNECH was established. On resection of the nodule, our patient's symptoms resolved, and she required no further therapy. On follow-up at 1.5 years, she was asymptomatic. DISCUSSION: DIPNECH is a rare lung condition presenting mainly with dry cough. CT chest can show solitary or bilateral pulmonary nodules, mosaic perfusion, bronchial wall thickening, ground-glass opacities, air trapping, or bronchiectasis. MiB-1 (antibody to Ki67) expressed in her case indicates tumor antigen expression supporting a diagnosis of DIPNECH vs. reactive hyperplasia. The miB-1 index was 1%, predicting low mitotic activity and a better prognosis. Tissue cultures of her resected specimen grew MAC. MAC is not known to be associated with such a preneoplastic condition. As per our literature review, only two other cases have been reported that describe the concurrence of pulmonary neuroendocrine growth and lung infection. MAC was associated in both these cases. Overall, most patients with DIPNECH experience a stable clinical course. However, severe clinical decline has been reported in a few. CONCLUSIONS: DIPNECH is a rare preneoplastic condition with a good prognosis, although it can sometimes progress to carcinoid tumors with clinical deterioration. Identification of risk factors may be helpful in timely diagnosis and treatment of DIPNECH. MAC is one such factor that seems to be associated with DIPNECH. Further studies should be undertaken to investigate their relationship. REFERENCE #1: Böhm J, Koch S, Gais P, Jütting U, Präuer HW, Höfler H. Prognostic value of MIB-1 in neuroendocrine tumours of the lung. J Pathol. 1996;178(4):402-409. doi:10.1002/(SICI)1096-9896(199604)178:4<402::AID-PATH498>3.0.CO;2-5 REFERENCE #2: Chassagnon G, Favelle O, Marchand-Adam S, De Muret A, Revel MP. DIPNECH: when to suggest this diagnosis on CT. Clin Radiol. 2015;70(3):317-325. doi:10.1016/j.crad.2014.10.012 REFERENCE #3: Krvavac A, Patel PH, Kamel G, Najmuddin M, Nayak RP, Patolia S. Pulmonary Neuroendocrine Cell Hyperplasia in a Patient with Mycobacterium avium Complex. Am J Respir Crit Care Med. 2018 Nov 1;198(9):e109-e110. doi: 10.1164/rccm.201801-0199IM. PMID: 30130431. DISCLOSURES: No relevant relationships by Lipisha Agarwal, source=Web Response No relevant relationships by Divyansh Bajaj, source=Web Response No relevant relationships by Chinmay Jani, source=Web Response No relevant relationships by Joseph Khoory, source=Web Response No relevant relationships by Abdullah Melhim, source=Web Response No relevant relationships by Gabriel Ryan, source=Web Response No relevant relationships by Harpreet Singh, source=Web Response

S3611 Double Trouble: Primary Lung and Colon Cancer in a Patient With Crohn’s Disease

Introduction: This vignette highlights the development of localized rectal adenocarcinoma and concomitant metastatic large cell neuroendocrine tumor of the lung in a patient with longstanding Crohn’s disease (CD) on Vedolizumab (VDZ). Case Description/Methods: A 61 year old male with a 2 year history of severe, uncontrolled colonic inflammatory CD presented to the ED with weakness, loss of appetite, and a 30lb weight loss over a 1 month period. He had been on VDZ 300mg every 8 weeks for 1 year. A CT chest showed a new 2cm pulmonary nodule with increasing mediastinal and perihilar lymphadenopathy. Bronchoscopy and endobronchial ultrasound were performed for lymph node sampling and revealed a large cell neuroendocrine tumor, which was later found to be metastatic to the brain. The patient was discharged with plans to optimize the VDZ therapy and start cancer treatment. Anticipating the use of immunotherapy, a colonoscopy was performed and revealed active inflammation in the sigmoid colon. Incidentally, an 18mm Is (sessile) polyp was found in the rectum and removed by piecemeal snare polypectomy. Pathology was consistent with invasive colonic adenocarcinoma. A colonoscopy one year earlier had been negative for malignancy. After a careful discussion in the GI tumor board, the decision was made to treat the lung cancer first. Unfortunately, the patient developed sepsis after his first chemotherapy dose and passed away. Discussion: This case illustrates the challenges with CD therapy during active malignancy. CD patients are at increased risk for both colonic adenocarcinoma and pulmonary malignancy. There have been isolated cases linking CD to premalignant diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, suggesting a possible correlation between CD and the highly aggressive large cell neuroendocrine tumor of the lung seen, though data is limited. VDZ has been associated with 24%-31% clinical remission of CD after induction. It was shown to be well tolerated and had a low risk of malignancy in patients with and without a history of prior malignancy. Data is limited on the use of VDZ concurrently with active chemotherapy, though it is presumed have a favorable safety profile given the gut-selective nature of the drug. The development of malignancies in this case is thought to be possibly related to CD and likely unrelated to VDZ. With limited data available, a multidisciplinary discussion between oncology and GI is ideal to develop a tailored treatment plan for CD patients with active malignancy.