[Pulmonary manifestations of Langerhans cell histiocytosis]

Langerhans cell histiocytosis with lung involvement in isolation and multisystem disease: Staging, natural history, and comparative survival

Langerhans cell histiocytosis (LCH) is a histiocytic neoplasm that can involve the lungs as single system (LCH-SSL) or multisystem disease (LCH-MSL). The role of full-body radiographic staging to determine whether patients have LCH-SSL or LCH-MSL is unclear. Long-term outcomes of LCH-SSL versus LCH-MSL and multisystem without lung involvement (LCH-MSNL) are unknown. A retrospective study of adult LCH patients seen at our center from January 2000 to 2020 was performed. In Part 1, we addressed utility of whole-body staging imaging among those presenting with isolated pulmonary signs or symptoms. Staging was defined as fluorodeoxyglucose positron emission tomography-computed tomography (CT) or whole-body CT obtained within 3 months of diagnosis. In Part 2, we examined the frequency of developing extra-pulmonary disease over time and mortality in patients with LCH-SSL. In Part 3, we compared the overall survival of LCH-SSL, LCH-MSL, and LCH-MSNL. Part 1: 240 patients with LCH were identified. A total of 112 (47%) had pulmonary signs or symptoms at presentation. Thirty-four (30%) underwent radiographic staging and only one showed evidence of extra-pulmonary disease. Part 2: 108 (45%) were LCH-SSL. Median follow-up duration of 4.5 years (95% confidence interval [CI]: 2.9-6.0). None developed extra-pulmonary disease. Part 3: 5-year survival: 94% (95% CI: 84%-98%) for LCH-SSL, 78% (95% CI: 59%-90%) for LCH-MSL, and 75% (95% CI: 53%-89%) for LCH-MSNL. LCH patients presenting with isolated pulmonary signs or symptoms rarely have extra-pulmonary involvement at the time of diagnosis and generally do not develop extra-pulmonary progression. LCH-SSL has the best overall survival, while LCH-MSL and LCH-MSNL have similar clinical outcomes.

[Cystic lung diseases]

Cystic lung diseases present uncommonly and have an undetermined incidence. Cysts result from a broad spectrum of causative mechanisms and diseases leading to variable clinical presentations. The pathogenic mechanisms that can lead to lung cyst formation include infection, neoplastic, systemic, traumatic, genetic and congenital processes. A rigorous, systemic and multidisciplinary approach is advised in the diagnostic workup of these conditions. In this article, we review cystic lung diseases including their presentation and management.

[Smoking cessation in smokers with pulmonary Langerhans cell histiocytosis - considerations from the management of ten patients]

Pulmonary Langerhans cell histiocytosis (PLCH) belongs to the spectrum of diffuse interstitial cystic pneumonias; it affects young people of both sexes and occurs almost exclusively in tobacco smokers or co-users of tobacco and cannabis. The management of this severe chronic disease is undertaken in specialized centers. A better understanding of the pathogenic mechanisms of the disease has opened up prospects for targeted therapies. However, supporting the abstinence from inhaling noxious materials which determine its prognosis remains the cornerstone of treatment. Patients with PLCH who persist in smoking despite the diagnosis may be very dependent on tobacco, experience significant difficulties in stopping smoking, and must have access to specialist smoking cessation clinics.

[Lung metastases of pancreatic adenocarcinoma: Watch for the second train!]

Pulmonary metastases due to a pancreatic cancer are difficult to diagnose and demonstrate a wide range of radiological patterns. We report the case of a 37-year-old female patient, without past medical history, with multicystic lung disease in a context of chronic abdominal pain, fatigue and weight loss. After several months of diagnostic delay, pathological examination of surgical lung biopsies led to the diagnosis of secondary deposits of pancreatic cancer. The clinical and radiogical situation deteriorated quickly with the development of alveolar consolidation and Aspergillus superinfection was then diagnosed. This case illustrates the value of an early decision to undertake surgical lung biopsy in the work-up of multicystic lung disease when cancer is suspected. In addition, in the specific context of cancer, faced with clinical and/or radiological deterioration, it is essential to look for infection, particularly aspergillosis.

[Emphysema, did you say emphysema?]

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a common condition that may initially look simple but may conceal other diseases capable of accelerating its natural history or even simulating it. We describe four cases presenting as COPD with emphysema that were reclassified on the basis of certain clinical characteristics and the radiological pattern.

CASE REPORTS

A 52 year old never smoking woman presenting with emphysema was eventually diagnosed as having lymphangioleiomyomatosis on the basis of an abdominal CT scan showing kidney angiomyolipomas. A 44 years old smoker presenting with rapidly evolving emphysema was eventually diagnosed as having Langerhans cell histiocytosis on the basis of a previous chest CT (four years earlier) showing cavitating nodules. An airport refueler, 73 years old, with severe emphysema despite never having smoked, was eventually diagnosed as suffering from alpha-1 antitrypsin deficiency. The last patient was a 54 year old man, a never smoker, who presented with severe airflow limitation and multilobar hyperlucency, with bronchiectasis in the same areas. He was eventually diagnosed as having a severe form of the Swyer-James-MacLeod syndrome.

CONCLUSION

These four case reports underline the importance of questioning the diagnosis of COPD when certain particular phenotypic characteristics are identified.

[Pulmonary Langerhans' cell histiocytosis (PLCH) revealed by pneumothorax: about a case]

L’histiocytose langerhansienne est une affection rare d’étiologie inconnue caractérisée par une infiltration d’un ou plusieurs organes, par des cellules de type Langerhans. Elle a une présentation clinique polymorphe. Nous rapportons le cas de Mr R.Y, âgé de 22 ans, tabagique à 8 PA, admis pour pneumothorax total spontané droit. Un drainage thoracique a été réalisé avec bonne évolution. La TDM thoracique de contrôle a objectivé de multiples formations kystiques diffuses prédominant aux lobes supérieurs. Un bilan a été réalisé à la recherche d’une histiocytose systémique mais s’est révélé négatif. L’évolution était marquée par la récidive du pneumothorax, le recours à une pleurodèse et la réalisation d’une biopsie pulmonaire qui a confirmé le diagnostic. Le diagnostic de l’HistiocytoseLangerhansienne doit être évoqué devant un pneumothorax sur poumon kystique. Le diagnostic est aisé devant un tableau clinique et radiologique évocateur. Néanmoins, les possibilités thérapeutiques restent limitées et la récidive du pneumothorax est fréquente.

Physiologic Determinants of Exercise Capacity in Pulmonary Langerhans Cell Histiocytosis: A Multidimensional Analysis

BACKGROUND

Reduced exercise capacity severely impacts quality of life in pulmonary Langerhans cell histiocytosis. Ascertaining mechanisms that impair exercise capacity is necessary to identify targets for symptomatic treatments.

METHODS

Dyspnea, pulmonary function tests and cardiopulmonary exercise test were analysed in 62 study participants. Data were compared between subjects with impaired and normal aerobic capacity (V'O2 peak less than 84% versus 84% predicted or more). Data were reduced using a principal component analysis. Multivariate analysis included V'O2 peak as the dependent variable and principal components as covariates.

RESULTS

V'O2 peak was reduced in 44 subjects (71%). Subjects with impaired aerobic capacity presented: (i) decreased FEV1, FVC, FEV1/FVC, DLCO and DLCO/VA and increased AaDO2, (ii) increased ventilatory equivalents at ventilatory threshold, VD/VT peak, AaDO2 peak and PaCO2 peak and decreased ventilatory reserve and PaO2 peak. There was no difference between groups in dyspnea scores. Principal component analysis extracted 4 principal components interpreted as follows: PC1: gas exchange; PC2: "pseudorestriction"; PC3: exercise-induced hyperpnea; PC4: air trapping. Multivariate analysis explained 65% of V'O2 peak. The 4 principal components were independently associated with V'O2 peak (βcoefficients: PC1: 9.3 [4.6; 14], PC2: 7.5 [3; 11.9], PC3: -5.3 [-9.6;-1.], PC4: -9.8 [-14,9;-4.7]).

CONCLUSION

Impaired exercise capacity is frequent in pulmonary Langerhans cell histiocytosis. It is mainly caused by pulmonary changes but is not associated with increased dyspnea intensity. Therefore, treating the lung represents a relevant approach for improving exercise capacity, even in patients experiencing mild dyspnea.