Pulmonary complications of type 1 neurofibromatosis

Pulmonary Hypertension in Chronic Lung Diseases: What Role Do Radiologists Play?

Pulmonary hypertension (PH) is a pathophysiological disorder, defined by a mean pulmonary arterial pressure (mPAP) > 20 mmHg at rest, as assessed by right heart catheterization (RHC). PH is not a specific disease, as it may be observed in multiple clinical conditions and may complicate a variety of thoracic diseases. Conditions associated with the risk of developing PH are categorized into five different groups, according to similar clinical presentations, pathological findings, hemodynamic characteristics, and treatment strategy. Most chronic lung diseases that may be complicated by PH belong to group 3 (interstitial lung diseases, chronic obstructive pulmonary disease, combined pulmonary fibrosis, and emphysema) and are associated with the lowest overall survival among all groups. However, some of the chronic pulmonary diseases may develop PH with unclear/multifactorial mechanisms and are included in group 5 PH (sarcoidosis, pulmonary Langerhans' cell histiocytosis, and neurofibromatosis type 1). This paper focuses on PH associated with chronic lung diseases, in which radiological imaging-particularly computed tomography (CT)-plays a crucial role in diagnosis and classification. Radiologists should become familiar with the hemodynamical, physiological, and radiological aspects of PH and chronic lung diseases in patients at risk of developing PH, whose prognosis and treatment depend on the underlying disease.

Age-dependent oral manifestations of neurofibromatosis type 1: a case-control study

INTRODUCTION

Most craniofacial manifestations of neurofibromatosis type 1 (NF1) are considered as a result of tumor compression. We sought to determine salivary changes, caries, and periodontal complications in NF1 patients without tumors in the oral cavity.

OBJECTIVE AND METHODS

Eleven NF1 patients without tumors in the oral cavity and 29 matched controls without NF1 were enrolled in this case-control study. Demographic information, medical history, and data of intraoral examinations, including the Decayed, Missing, and Filled Teeth (DMFT) scores and Russel's periodontal index (PI), were recorded. The functional salivary analysis was performed for sialometry, salivary pH values, and amylase activity. Ingenuity Systems Pathway Analysis (IPA) was conducted to identify mutually activated pathways for NF1-associated oral complications.

RESULTS

NF1 patients were associated with periodontitis (OR = 1.40, 95% CI = 1.06-1.73, P = 0.04), gingivitis (OR = 1.55, 95% CI = 1.09-2.01, P = 0.0002), and decreased salivary flow rates (OR = 1.40, 95% CI = 1.05-1.76, P = 0.005). Periodontal destruction, salivary changes, and dental caries in NF1 patients were age-dependent. Subgroup analyses based on age stratification suggested that salivary flow rates and salivary amylase activities were significantly low in NF1 patients aged over 20 years and that salivary pH values, PI and DMFT scores were significantly high among NF1- controls aged over 20. All oral complications were not significantly presented in NF1 patients aged below 20 years. IPA analyses suggested that cellular mechanisms underlying NF1-associated oral complications involved chronic inflammatory pathways and fibrosis signaling pathway.

CONCLUSION

NF1 patients without tumors in the oral cavity presented a comparatively high prevalence of age-dependent oral complications, including periodontal destruction and salivary gland dysfunction, which were associated with chronic inflammatory pathogenesis.

Neurofibromatosis type 1: evaluation by chest computed tomography

Objective

The aim of this study was to evaluate chest computed tomography (CT) findings in patients diagnosed with neurofibromatosis type 1 (NF1).

Material and Methods

This was a retrospective study in which we reviewed the chest CT scans of 14 patients diagnosed with NF1 and neurofibromatosis-associated diffuse lung disease (NF-DLD). The sample comprised eight women and six men. The median age was 55 years (range, 11-75 years). The diagnosis of NF1 was made on the basis of the diagnostic criteria established by the U.S. National Institutes of Health. The images were analyzed by two chest radiologists, who reached decisions by consensus.

Results

The predominant CT finding of NF-DLD was multiple cysts, which were observed in 13 patients (92.9%), followed by emphysema, in eight (57.1%) and subpleural bullae, in six (42.9%). Other findings included subcutaneous neurofibromas, in 12 patients (85.7%), ground-glass opacities, in one (7.1%), and tracheobronchial neurofibromas, in one (7.1%). The pulmonary abnormalities were bilateral in 12 cases (85.7%). The abnormalities were predominantly in the upper lung fields in eight cases (57.1%), and their distribution was random in 11 (78.6%).

Conclusion

Pulmonary cysts, emphysema, and subpleural bullae appear to be the chest CT findings that are most characteristic of NF-DLD.

Neurofibromatosis-associated pulmonary hypertension: an ominous duo

The authors report a rare clinical case of a patient with neurofibromatosis type 1 (NF1) complicated by pulmonary hypertension (PH), which presents with rapid progression. An exhaustive investigation was performed to identify the main aetiology of the PH. It was concluded that the PH could be associated with NF1, and so belonged in group 5 of the clinical classification of PH. In general, such patients have a poor long-term prognosis due to the inexistence of proven, effective treatment. Further studies are needed to better understand the mechanisms of NF1-associated PH.

Neurofibromatosis type 1: State-of-the-art review with emphasis on pulmonary involvement

Neurofibromatosis type 1 (NF-1), also known as von Recklinghausen's disease, is an autosomal dominant dysplasia of the ectoderm and mesoderm with a variable clinical expression, but near-complete penetrance before the age of 5 years. The estimated incidence is 1 in 3000 births. NF-1 is characterized by collections of neurofibromas, café-au-lait spots, axillary and inguinal freckling, and pigmented hamartomas in the iris (Lisch nodules). Pulmonary manifestations of NF-1, which usually include bilateral basal reticulations and apical bullae and cysts, are reported in 10-20% of adult patients. Clinically, neurofibromatosis-associated diffuse lung disease (NF-DLD) usually presents with nonspecific respiratory symptoms, including dyspnea on exertion, shortness of breath, and chronic cough or chest pain, at the time of diagnosis. Computed tomography (CT) is highly accurate for the identification and characterization of NF-DLD; it is the most reliable method for the diagnosis of this lung involvement. Various CT findings of NF-DLD, including cysts, bullae, ground-glass opacities, bibasilar reticular opacities, and emphysema, have been described in patients with NF-1. The typical CT pattern, however, is characterized by upper-lobe cystic and bullous disease, and basilar interstitial lung disease. Currently, the goal of NF-DLD treatment is the earliest possible diagnosis, focusing on symptom relief and interventions that positively alter the course of the disease, such as smoking cessation. The aim of this review is to describe the main clinical, pathological, and imaging aspects of NF-1, with a focus on pulmonary involvement.

Interstitial lung disease and pre-capillary pulmonary hypertension in neurofibromatosis type 1

Although previously reported, the existence of a neurofibromatosis (NF)-associated diffuse lung disease (DLD) still lacks solid evidence. We report a case of a 68-year-old non-smoking female with NF1, pre-capillary pulmonary hypertension (PH) and an interstitial lung pattern. Initial findings included progressive dyspnea, hypoxemia and sparse centrilobular ground-glass micronodules on high-resolution computed tomography (HRCT). Further study demonstrated a severe defect in diffusing capacity for carbon monoxide (DLCO), macrophages on bronchoalveolar lavage and pre-capillary PH on right cardiac catheterization. Surgical biopsy revealed macrophage accumulation along bronchovascular bundles and alveolar spaces and type II pneumocytes hyperplasia. Given the absence of environmental exposure or new drugs, a NF-DLD was hypothesized. Pre-capillary PH was disproportionate to interstitial findings, so it was attributed to a NF1-vasculopathy. Treatment with triple sequential combined therapy was unsuccessful culminating in death 18 months later. This case adds HRCT and anatomopathological data suggesting NF-DLD as a distinct manifestation of the disease.

[Spontaneous hemothorax: a rare complication of neurofibromatosis type 1]

Neurofibromatosis type 1 (NF1), also known as Von Recklinghausen's disease is an autosomal dominant genetic disorder. It is the most common of phacomatoses. Pulmonary complications have been rarely described in the literature. Vascular complications have been reported in 3.6% of patients. We here report the case of a 38-year old female patient, followed-up for neurofibromatosis type 1, admitted to the Emergency Department with hemorrhagic shock. Clinical examination showed several coffee-with-milk colored spots, many plexiform neurofibromas, left-sided pleural effusion syndrome. Pleural puncture objectified coagulable haemorrhagic fluid. The patient received transfusion and emergency chest drainage. Patient's assessment was completed by angioscanner which showed no pulmonary embolism or other associated lesions. Spontaneous hemothorax is a rare and severe complication of neurofibromatosis. It is probably due to vascular injury caused by this disease.

Severe dyspnea in a patient with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a genetic disease in which pulmonary complications are rare, but severe, especially pulmonary hypertension (PH). The mechanisms underlying the onset of PH in patients with NF1 are unclear and might be multifactorial. In particular, the frequent presence of pulmonary parenchymal lesions makes etiological diagnosis of PH difficult. We describe here the case of a patient with NF1 admitted to our clinic with dyspnea and right heart failure revealing severe pre-capillary PH. Parenchymal lesions were mild and PH was attributed to pulmonary vascular involvement. Clinical and hemodynamic conditions of the patient improved under pulmonary arterial hypertension-specific combination therapy. This case suggests that treatment of PH due to pulmonary vascular involvement in NF1 may be aligned with recommendations for PAH treatment.

The role of genetics in pulmonary arterial hypertension

Group 1 pulmonary hypertension or pulmonary arterial hypertension (PAH) is a rare disease characterized by proliferation and occlusion of small pulmonary arterioles, leading to progressive elevation of pulmonary artery pressure and pulmonary vascular resistance, and right ventricular failure. Historically, it has been associated with a high mortality rate, although, over the last decade, treatment has improved survival. PAH includes idiopathic PAH (IPAH), heritable PAH (HPAH), and PAH associated with certain medical conditions. The aetiology of PAH is heterogeneous, and genetics play an important role in some cases. Mutations in BMPR2, encoding bone morphogenetic protein receptor 2, a member of the transforming growth factor-β superfamily of receptors, have been identified in 70% of cases of HPAH, and in 10-40% of cases of IPAH. Other genetic causes of PAH include mutations in the genes encoding activin receptor-like type 1, endoglin, SMAD9, caveolin 1, and potassium two-pore-domain channel subfamily K member 3. Mutations in the gene encoding T-box 4 have been identified in 10-30% of paediatric PAH patients, but rarely in adults with PAH. PAH in children is much more heterogeneous than in adults, and can be associated with several genetic syndromes, congenital heart disease, pulmonary disease, and vascular disease. In addition to rare mutations as a monogenic cause of HPAH, common variants in the gene encoding cerebellin 2 increase the risk of PAH by approximately two-fold. A PAH panel of genes is available for clinical testing, and should be considered for use in clinical management, especially for patients with a family history of PAH. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.