Long-term Outcomes of Adult Pulmonary Langerhans Cell Histiocytosis: A Prospective Cohort

BackgroundThe long-term outcomes of adult pulmonary Langerhans cell histiocytosis (PLCH), particularly survival, are largely unknown. Two earlier retrospective studies reported a high rate of mortality, which contrasts with our clinical experience.MethodsTo address this issue, all newly diagnosed PLCH patients referred to the French national reference centre for histiocytoses between 2004 and 2018 were eligible for inclusion. The primary outcome was survival, which was defined as the time from inclusion to lung transplantation or death from any cause. Secondary outcomes included the cumulative incidences of chronic respiratory failure (CRF), pulmonary hypertension (PH), malignant diseases, and extra-pulmonary involvement in initially isolated PLCH. Survival was estimated using the Kaplan-Meier method.ResultsTwo hundred six patients (mean age: 39±13 years, 60% females, 95% current smokers) were prospectively followed for a median duration of 5.1 years (interquartile range [IQR], 3.2 to 7.6). Twelve (6%) patients died. The estimated rate of survival at 10 years was 93% (95% confidence interval [CI], 89–97). The cumulative incidences of CRF and/or PH were less than 5% at both 5 and 10 years, and 58% of these patients died. Twenty-seven malignancies were observed in 23 patients. The estimated standardized incidence ratio of lung carcinoma was 17.0 (95% CI, 7.45–38.7) compared to an age- and sex-matched French population. Eight (5.1%) of the 157 patients with isolated PLCH developed extra-pulmonary involvement.ConclusionsThe long-term prognosis of PLCH is significantly more favourable than was previously reported. Patients must be closely monitored after diagnosis to detect severe complications early.

A Case of Pulmonary Adenocarcinoma Presenting with Diffuse Cystic Lesions

The main causes of diffuse cystic lung diseases include lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, lymphoid interstitial pneumonia, light chain deposition disease, <i>Pneumocystis jirovecii</i> pneumonia, hypersensitivity pneumonitis, and desquamative interstitial pneumonia. Diffuse cystic lung diseases are rarely caused by a malignant process, which are secondary to metastases from sarcomas and gastrointestinal and gynecologic adenocarcinomas. Here, we present a rare case of invasive pulmonary adenocarcinoma associated with progressive diffusion of cystic lesions, revealed by chronic cough and progressive shortness of breath. It is important for clinicians to be aware of this unusual imaging manifestation of lung cancer, to avoid misdiagnoses.

The etiology of diffuse cystic lung diseases: an analysis of 1010 consecutive cases in a LAM clinic

Background The differential diagnosis of diffuse cystic lung disease (DCLD) is a clinical challenge. We wish to analyze the distribution of the etiology of DCLD based on data from a single lymphangioleiomyomatosis (LAM) clinic. Methods All DCLD patients at the LAM Clinic of Peking Union Medical College Hospital between January 2006 and December 2019 were analyzed. Information on the demographic, clinical, radiological, and pathological features was collected. Results A total of 1010 patients with DCLD on CT scan were evaluated. A sum of 711(70.4%) patients were diagnosed with definite or probable LAM. Other diagnoses included Birt–Hogg–Dubé syndrome (46), Sjogren's syndrome (38), pulmonary Langerhans cell histiocytosis (14), lung tumors (3), Castleman disease (2), antineutrophil cytoplasmic antibody-associated vasculitis (2), systemic lupus erythematosus (1), Marfan syndrome (1), amyloidosis (1), congenital cystic adenomatoid malformation of the lung (1), and pleuroparenchymal fibroelastosis (1). In the 38 patients diagnosed with Sjogren's syndrome, 2 were diagnosed with light-chain deposition disease, 2 were diagnosed with amyloidosis and 1 was diagnosed with lymphocytic interstitial pneumonia. One hundred and eighty-nine patients (18.7%) were undiagnosed. Lung biopsy results were available in 27 patients in the undiagnosed DCLD group but did not provide a diagnosis. Conclusion Approximately 70% of DCLD patients in our LAM clinic had LAM. The common differential diagnoses included Birt–Hogg–Dubé syndrome, Sjogren’s syndrome, and pulmonary Langerhans cell histiocytosis. Detailed clinical information and laboratory, genetic, and pathological investigations provide correct diagnoses in most patients with DCLD.