The characteristics of the pulmonary cysts on the high-resolution computed tomography (HRCT) chest images are an important diagnostic clue to distinguish among cystic lung diseases. The diagnostic accuracy of HRCT was reported to be as high as 90% by experienced pulmonologists and radiologists. Herein, we report the case of an elderly woman with Birt-Hogg-Dubé syndrome (BHDS) whose HRCT images displayed lymphangioleiomyomatosis-like features of the pulmonary cysts, rendering it difficult for us to diagnose BHDS. This case illustrates the significance of a thorough anamnesis, physical examination, and skin biopsy of facial papules to establish an accurate diganosis.

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, Pneumocystis jirovecii 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.

BACKGROUND: Over the last 2 decades, great progress has been made in the understanding of the clinical aspects and pathogenesis of lymphangioleiomyomatosis (LAM), leading to publication of guidelines and approval of an effective therapy.
OBJECTIVE: Aim of our study was to describe how the management and the natural history of this rare disease have changed after the publication of the ERS and American Thoracic Society/Japanese Respiratory Society guidelines and the introduction of sirolimus.
METHODS: We examined 162 LAM patients followed at our center between 2001 and 2017, reporting clinical characteristics and diagnostic approach. Response to sirolimus in patients undergoing long-term treatment and mortality risk, estimated in terms of cumulative incidence taking into account organ transplantation as a competing cause of the event, were evaluated. The difference in the cumulative incidence between the patients admitted to the observation before 2011 and after 2011, year of the publication of the MILES trial for the efficacy of sirolimus, has also been estimated.
RESULTS: Sixty-one patients had a histological diagnosis (22 from 2010 onward). 101 patients received a radiological diagnosis according to the guidelines criteria. Pulmonary function tests remained stable over a 3-year treatment period in patients who received sirolimus for over 12 months. The cumulative incidence of mortality after 10 years in the whole population was 25.5%. The cumulative incidence of mortality after 5 years was significantly lower in patients who entered the study since 2011 (after publication of the MILES trial) than in patients who entered the study before.
CONCLUSIONS: We provide the data supporting the long-term efficacy of sirolimus therapy in a large cohort of patients with functional impairment and other manifestations of the disease. Our results also suggest that the advent of sirolimus and the publication of international guidelines changed the natural history of the disease lowering the mortality and reducing the need of invasive diagnostic techniques.

暂无摘要。

Birt-Hogg-Dubé syndrome (BHDS) is a rare, genetic, autosomal dominant disease caused by mutation in a folliculin gene. This syndrome is characterised by three main symptoms: benign lesions originating from hair follicles, variously shaped cysts in the lungs, and various types of benign and malignant kidney neoplasms. In our article we are going to present cases of two sisters with BHDS. In the case of the first sister skin lesions were accompanied by lung abnormalities. The second sister, however, presented with recurrent pneumothoraces associated with variously shaped lung cysts located mainly below the tracheal carina. In both instance diagnosis was confirmed by genetic test.

Solitary or multiple pulmonary cysts are a relatively rare finding and should always prompt the search for an underlying cause. High-resolution computed tomography (HRCT) plays a crucial role in the differential diagnosis with morphological findings, such as cyst shape and size, wall consistency, number, distribution and localization of the cysts being the important criteria. The differentiation of diseases with multiple, diffusely distributed cysts from diseases with single or grouped cysts facilitates the definition of the final diagnosis. Associated pulmonary findings, such as nodules, ground-glass opacities and fibrosis or pleural changes also play a role. Possible underlying diseases can have systemic, inhalative, traumatic, genetic or infectious causes.

The pathogenesis of pulmonary hypertension (PH) in lymphangioleiomyomatosis (LAM) has not yet been completely clarified. The aim of this study was to conduct a noninvasive evaluation of the main hemodynamic mechanisms of exercise-induced PH in patients with LAM, assessed using exercise stress echocardiography.
Fifteen patients with LAM (mean age, 47 ± 13 years; all women) without resting PH were enrolled in a prospective single-center study and compared with 15 healthy female control subjects (mean age, 45.2 ± 8 years; P = .65). A complete echocardiographic study with Doppler tissue imaging was performed at baseline and during semisupine symptom-limited exercise testing to evaluate (1) left ventricular systolic and diastolic function, (2) right ventricular contractile function, (3) estimated pulmonary capillary wedge pressure, (4) estimated systolic and mean pulmonary artery pressure, and (5) estimated pulmonary vascular resistance.
Compared with healthy control subjects, patients with LAM during exercise showed echocardiographic signs of right ventricular overload and right ventricular systolic dysfunction and significant increases in mean pulmonary artery pressure (14.4 ± 6.5 vs 4.2 ± 3.1 mm Hg, P < .0001), pulmonary vascular resistance (+68.3 ± 42.1 vs -0.1 ± 18.3 dyne-sec/cm5, P < .0001), and, unexpectedly, pulmonary capillary wedge pressure (+8.3 ± 5.3 vs -0.5 ± 1.3 mm Hg, P < .0001).
Exercise-induced PH in patients with LAM could be related not only to hypoxic pulmonary vascular vasoconstriction during exercise (precapillary PH) but also to a significant exercise-induced increase in estimated pulmonary capillary wedge pressure, probably secondary to diastolic dysfunction (postcapillary PH).

We present the case of a man with Mounier-Kuhn syndrome (MKS), or tracheobronchomegaly, who was referred to the National Institutes of Health Clinical Research Center because of a potential diagnosis of lymphangioleiomyomatosis (LAM), a rare condition in men. The patient was evaluated using ongoing protocols and provided written informed consent. The case demonstrates the presence of chronic inflammation surrounding the dilated airways and histologic changes of the lung parenchyma with emphysematouslike disruption in areas adjacent to the dilated airways. This finding suggests that damage to the lung parenchyma is an ongoing phenomenon in MKS. Moreover, our analysis of CT images indicates similar abnormalities in areas remote from the dilated airways. Finally, because of increased anatomic dead space, calculation of lung diffusion capacity by the single-breath method yielded abnormally low values that required making a correction for the large anatomic dead space, which can be measured by the single-breath nitrogen washout test.

We describe a case of a young man presenting with exertional dyspnea. His chest radiograph showed hyperlucency in his left lung, and he was subsequently diagnosed to have giant bullous emphysema. An approach to lesions of decreased attenuation on computed tomography of the chest, with a focus on cystic lung diseases is discussed. This is followed by a literature review of the clinical presentation, natural history, radiology and management of giant bullous emphysema. Although this is an uncommon condition, a clinician has to be cognizant of the fact that it may mimic other common respiratory diseases. This review highlights the importance of these caveats as misguided treatment options may lead to devastating consequences.