Familial spontaneous pneumothorax

Analysis of patients undergoing surgical treatment for primary spontaneous pneumothorax

Background

Primary spontaneous pneumothorax (psp) results from spontaneous rupture of bleb or bulla. Aims: We planned to discuss the etiologic factors, clinical and radiological findings, and treatment results of psp cases.

Materials and Methods

402 patients were evaluated. Patients were divided into two groups as patients receiving positive results with thoracostomy and patients who received positive results"> thoracotomy/video-assisted thoracoscopic surgery (vats). Groups were compared. Results were evaluated"> using Chi-square or Fishers' exact test. P < 0.05 was considered as significant.

Results

Gender difference (P: 1.00) and localization of disease (P: 0.45)were not significant for psp. Smoking and being subtotal or total compared to partial had a substantial effect on the implementation of thoracotomy/vats (P < 0.05). Furthermore, psp was most frequently seen in August and September.

Discussion

Risk factors of psp are described as genetic predisposition, being tall, smoking, and autosomal dominant heredity. The main determinant factor in the treatment of psp is the degree of pneumothorax.

Conclusion

Psp was frequently observed in smokers. The preferred method for overall psp is tube thoracostomy. Thoracotomy/vats is more commonly performed for subtotal or total psp compared to partial psp.

Familial spontaneous pneumothorax: importance of screening for Birt-Hogg-Dubé syndrome

OBJECTIVES

The goal of this study was to investigate the prevalence of Birt-Hogg-Dubé (BHD) syndrome in patients with familial spontaneous pneumothorax (FSP) and the clinical characteristics of pneumothorax related to BHD syndrome compared with those of primary spontaneous pneumothorax.

METHODS

A total of 37 families diagnosed with FSP from 2007 to 2017 were enrolled in this study. The FLCN gene, which is responsible for BHD syndrome, was sequenced using the Sanger method in 25 probands. For the patients with confirmed BHD syndrome-related pneumothorax, clinical characteristics including the median onset age of pneumothorax, the male-to-female ratio, the mean height and body mass index (BMI) and the recurrence rate after different treatment modalities were obtained and compared with those of patients with primary spontaneous pneumothorax.

RESULTS

Of the 25 probands with FSP, 16 [64.0%, 95% confidence interval (CI) 43.8-84.2%] harboured FLCN germline mutations. In the patients with BHD syndrome-related pneumothorax, the median onset age of pneumothorax was 34 years; the male-to-female ratio was 1.3:1; and the mean height and BMI were 167.0 ± 8.6 cm and 23.6 ± 3.4 kg/m2, respectively. These characteristics were significantly different from those in patients with primary spontaneous pneumothorax from the same centre. The recurrence rate of BHD syndrome-related pneumothorax after conservative therapy was 53.1% (95% CI 38.6-67.5%) compared with 9.1% (95% CI 0-19.4%) after surgical treatment.

CONCLUSIONS

BHD syndrome is one of the most common causes of FSP. Patients with FSP should be recommended for mutation screening for the FLCN gene to facilitate early diagnosis and proper intervention.

Combining clinical, radiological and genetic approaches to pneumothorax management

Familial spontaneous pneumothorax (FSP) accounts for 10% of primary spontaneous pneumothoraces. Appropriate investigation of FSP enables early diagnosis of serious monogenic diseases and the practice of precision medicine. Here, we show that a pneumothorax genetics multidisciplinary team (MDT) can efficiently diagnose a range of syndromic causes of FSP. A sizeable group (73.6%) of clinically unclassifiable FSPs remains. Using whole genome sequencing we demonstrate that most of these cases are not known monogenic disorders. Therefore, clinico-radiological assessment by an MDT has high sensitivity for currently known clinically important monogenic causes of FSP, which has relevance for the design of efficient pneumothorax services.

Spontaneous pneumothorax-When do we need to intervene?

BACKGROUND

Pneumothorax can be classified as traumatic, iatrogenic or spontaneous (SP), which can be subdivided into primary spontaneous pneumothorax (PSP), a condition without preexisting lung disease, or secondary spontaneous pneumothorax (SSP) a complication of a preexisting lung disease. Recurrence rate of PSP is 30% whereas for SSP rate is unknown. This article explores the experience of a tertiary center over 20 years.

METHODS

A retrospective case review of patients hospitalized with pneumothorax to investigate the natural history and treatment of SP in a young population in a single tertiary center was conducted. A search of the digital archive (going back to 01/01/1995) of Sheba Medical Center identified hospitalized patients below the age of 40.

RESULTS

The database was composed of the records of 750 patients (612 males, 138 females) who were hospitalized. The recurrence risk for SP after nonoperative treatment was significantly higher. Women were found to have an increased risk of SSP when having SP (OR 2.78). Asthma was the most prevalent disease causing SSP in young people.

CONCLUSIONS

In this large cohort, we found that operative procedure has clear protective effect from recurrence in SP, so surgery should be positively considered when treating SP in hospitalized patients. Among young people and particularly in pediatric patients, when females have a SP, we strongly recommend looking for primary lung disease. More studies are needed to determine the risk factors and produce clear guidelines regarding surgery as first treatment.

Familial spontaneous pneumothorax and Machado–Joseph disease

We report the first known case of a 42-year-old man diagnosed with spinocerebellar ataxia type 3, also known as Machado–Joseph disease (MJD), who presented with recurrent spontaneous pneumothorax. Six other family members affected with MJD died of the same pulmonary complication. To date, there has been no direct genetic linkage between MJD and familial spontaneous pneumothorax. However, the mutated ataxin-3 (ATXN3) gene in MJD and Serpin Family A Member 1 (SERPINA1) gene in hereditary emphysema share the same loci on chromosome 14q32.1, which is suggestive of genetic proclivity of patients with MJD to develop familial pneumothorax. Furthermore, the abnormal ataxin protein encoded by ATXN3 and the patient’s smoking history could have potentiated the dysregulation of the ubiquitin-proteasome system further aggravating his genetic predisposition to develop recurrent pneumothorax. These unexplored areas of inquiry invoke further molecular characterization to give an accent to medical knowledge as well as guide novel therapies in the future.

Recurrent primary spontaneous pneumothorax in a large Chinese family: a clinical and genetic investigation

BACKGROUND

Primary spontaneous pneumothorax (PSP) is a common manifestation of Birt-Hogg-Dubé (BHD) syndrome, which is an autosomal dominant disorder caused by mutation of the folliculin (FLCN) gene. This study was established to investigate the mutation of the FLCN gene and the phenotype in a family with PSP.

METHODS

We investigated the clinical and genetic characteristics of a large Chinese family with recurrent spontaneous pneumothorax. Genetic testing was performed by Sanger sequencing of the coding exons (4-14 exons) of the FLCN gene.

RESULTS

Among ten affected members in a multi-generational PSP kindred, with a total of 18 episodes of spontaneous pneumothorax, the median age for the initial onset of pneumothorax was 42.5 years (interquartile range: 28.8-57.2 years). Chest computed tomography scan of the proband showed pulmonary cysts and pneumothorax. A novel nonsense mutation (c.1273C>T) in exon 11 of FLCN gene that leads to a pre-mature stop codon (p.Gln425*) was identified in the family. The genetic analysis confirmed the diagnosis of BHD syndrome in this family in the absence of skin lesions or renal tumors.

CONCLUSIONS

A novel nonsense mutation of FLCN gene was found in a large family with PSP in China. Our results expand the mutational spectrum of FLCN gene in patients with BHD syndrome.

FLCN-regulated miRNAs suppressed reparative response in cells and pulmonary lesions of Birt-Hogg-Dubé syndrome

Background

Birt-Hogg-Dubé Syndrome (BHDS) characterised by skin fibrofolliculomas, kidney tumour and pulmonary cysts/pneumothorax is caused by folliculin (FLCN) germline mutations. The pathology of both neoplasia and focused tissue loss of BHDS strongly features tissue-specific behaviour of the gene. Isolated cysts/pneumothorax is the most frequent atypical presentation of BHDS and often misdiagnosed as primary spontaneous pneumothorax (PSP). Deferential diagnosis of BHDS with isolated pulmonary presentation (PSP-BHD) from PSP is essential in lifelong surveillance for developing renal cell carcinoma.

Methods

The expression profiles of microRNAs (miRNAs) in cystic lesions of PSP-BHD and PSP were determined via microarray. The selected upregulated miRNAs were further confirmed in the plasma of an expanded cohort of PSP-BHD patients by reverse transcription quantitative PCR (RT-qPCR). Their diagnostic accuracy was evaluated. Moreover, the cellular functions and targeted signalling pathways of FLCN-regulated miRNAs were assessed in various cell lines and in the lesion tissue contexts.

Results

Cystic lesions of PSP-BHD and PSP showed different miRNAs profiles with a significant upregulation of miR-424–5p and let-7d-5p in PSP-BHD. The combination of the two effectively predicted BHDS patients. In vitro studies revealed a suppressive effect of FLCN on miR-424–5p and let-7d-5p expressions specifically in lung epithelial cells. The ectopic miRNAs triggered epithelial apoptosis and epithelial transition of mesenchymal cells and suppressed the reparative responses in cells and tissues with FLCN deficiency.

Conclusion

The upregulation of miR-424–5p and let-7d-5p by FLCN deficiency occurred in epithelial cells and marked the PSP-BHD condition, which contributed to a focused degenerative pathology in the lung of PSP-BHD patients.

A novel FLCN mutation in family members diagnosed with primary spontaneous pneumothorax

Background

Primary spontaneous pneumothorax (PSP) is a disease characterized by the accumulation of air in the pleural space between the lung and thoracic wall. It is more common in young, tall, thin, and asthenic men. A family history was reported for approximately 11.5% of individuals admitted with PSP. The literature has reported cases diagnosed with familial PSP, who have no manifestations of Birt–Hogg–Dubé (BHD) syndrome but mutations in different exons of the Folliculin (FLCN) gene. The aim of this study is to present a Turkish family in which 13 members from three generations of the same family developed recurrent isolated spontaneous pneumothorax with a novel mutation in the FLCN.

Methods

A male proband was diagnosed with spontaneous pneumothorax in the emergency department of the University of Health Sciences Haydarpasa Numune Training and Research Center, Istanbul, Turkey. His 12 relatives from three generations diagnosed with PSP, as revealed by his family history, were invited to the hospital to give blood samples for mutation analysis. The Sanger sequence data of FLCN were analyzed on the ENSEMBL website using SeqScape 3 and Codon Aligner software.

Results

A novel heterozygous mutation c. 1273C>T (p.Gln425Ter) was detected in exon 11 of the FLCN, which caused PSP in the proband and his 12 relatives tested using Sanger sequencing.

Conclusion

We found that a heterozygous mutation in exon 11 of FLCN c. 1273C>T (p.Gln425Ter), which was identified for the first time in our study, might cause isolated familial spontaneous pneumothorax.

The Relevance of Family History Taking in the Detection and Management of Birt-Hogg-Dubé Syndrome

BACKGROUND

Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal-dominant inherited disorder characterized by inactivation of the gene Folliculin (FLCN), pulmonary cysts with recurrent spontaneous pneumothorax, dermatological lesions, and an increased risk of developing renal malignancies.

OBJECTIVES

We aimed to investigate the real prevalence of BHDS and its prevalence among patients with a familial history of pneumothorax.

METHODS

From July 2014 to December 2016, we consecutively studied all patients with spontaneous pneumothorax and a positive family history for the same condition referring to our Institution. The suspicious cases underwent genetic analysis of the BHDS-causative gene FLCN. FLCN-positive cases were further evaluated with routine blood tests, chest radiography, chest CT, abdominal MRI, and dermatological evaluation.

RESULTS

Among 114 patients admitted with spontaneous pneumothorax, 7 patients had a family history of pneumothorax, and 6/7 (85.7%) patients had positive genetic test for FLCN as well as 7/13 family members. Pulmonary cysts were found in all patients with a FLCN-positive genetic test. Most patients (10/13, 76.9%) had tiny pulmonary cysts less than 1 cm in diameter. The vast majority of cysts were intraparenchymal (12/13, 92.3%) and located in lower lobes. Dermatological lesions were found in 7/13 (54%) patients, renal cysts in 4/13 (31%) patients, and renal cancer in 1 (1/13, 7.7%) patient.

CONCLUSIONS

Although BHDS is considered a rare disease, BHDS underlies spontaneous pneumothorax more often than usually believed, especially whenever a family history of pneumothorax is present. Diagnosis of BHDS is essential to start monitoring patients for the risk of developing renal malignancies.

Spontaneous Pneumothoraces in Patients with Birt-Hogg-Dubé Syndrome

RATIONALE

Spontaneous pneumothorax is a common complication of Birt-Hogg-Dubé syndrome (BHD).

OBJECTIVES

The optimal approach to treatment and prevention of BHD-associated spontaneous pneumothorax, and to advising patients with BHD regarding risk of pneumothorax associated with air travel, is not well established.

METHODS

Patients with BHD were recruited from the Rare Lung Diseases Clinic Network and the BHD Foundation and surveyed about disease manifestations and air travel experiences.

RESULTS

A total of 104 patients completed the survey. The average age at diagnosis was 47 years, with an average delay from first symptoms of 13 years. Pulmonary cysts were the most frequent phenotypic manifestation of BHD, present in 85% of patients. Spontaneous pneumothorax was the presenting manifestation that led to the diagnosis of BHD in 65% of patients, typically after the second episode (mean, 2.4 episodes). Seventy-nine (76%) of 104 patients had at least one spontaneous pneumothorax during their lifetime, and 82% had multiple pneumothoraces. Among patients with multiple pneumothoraces, 73% had an ipsilateral recurrence, and 48% had a subsequent contralateral spontaneous pneumothorax following a sentinel event. The mean ages at first and second pneumothoraces were 36.5 years (range, 14-63 yr) and 37 years (range, 20-55 yr), respectively. The average number of spontaneous pneumothoraces experienced by patients with a sentinel pneumothorax was 3.6. Pleurodesis was generally performed after the second (mean, 2.4) ipsilateral pneumothorax and reduced the ipsilateral recurrence rate by half. A total of 11 episodes of spontaneous pneumothorax occurred among eight patients either during or within the 24-hour period following air travel, consistent with an air travel-related pneumothorax rate of 8% per patient and 0.12% per flight. Prior pleurodesis reduced the occurrence of a subsequent flight-related pneumothorax.

CONCLUSIONS

Spontaneous pneumothorax is an important, recurrent manifestation of pulmonary involvement in patients with BHD, and pleurodesis should be considered following the initial pneumothorax to reduce the risk of recurrent episodes. In general, in patients with BHD, pneumothorax occurs in about 1-2 per 1,000 flights, and the risk is lower among patients with a history of prior pleurodesis.

Spontaneous pneumothorax in diffuse cystic lung diseases

PURPOSE OF REVIEW

Diffuse cystic lung diseases (DCLDs) are a heterogeneous group of disorders with varying pathophysiologic mechanisms that are characterized by the presence of air-filled lung cysts. These cysts are prone to rupture, leading to the development of recurrent spontaneous pneumothoraces. In this article, we review the epidemiology, clinical features, and management DCLD-associated spontaneous pneumothorax, with a focus on lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, and pulmonary Langerhans cell histiocytosis.

RECENT FINDINGS

DCLDs are responsible for approximately 10% of apparent primary spontaneous pneumothoraces. Computed tomography screening for DCLDs (Birt-Hogg-Dubé syndrome, lymphangioleiomyomatosis, and pulmonary Langerhans cell histiocytosis) following the first spontaneous pneumothorax has recently been shown to be cost-effective and can help facilitate early diagnosis of the underlying disorders. Patients with DCLD-associated spontaneous pneumothorax have a very high rate of recurrence, and thus pleurodesis should be considered following the first episode of spontaneous pneumothorax in these patients, rather than waiting for a recurrent episode. Prior pleurodesis is not a contraindication to future lung transplant.

SUMMARY

Although DCLDs are uncommon, spontaneous pneumothorax is often the sentinel event that provides an opportunity for diagnosis. By understanding the burden and implications of pneumothoraces in DCLDs, clinicians can facilitate early diagnosis and appropriate management of the underlying disorders.

Clinical and genetic study of a large Chinese family presented with familial spontaneous pneumothorax

BACKGROUND

Familial spontaneous pneumothorax (FSP) is an inherited disease, and Birt-Hogg-Dubé (BHD) syndrome is its leading cause. BHD syndrome is an autosomal dominant disorder characterized by pulmonary cysts, spontaneous pneumothorax, renal cancer, and skin fibrofolliculomas. It is caused by germline mutations in the FLCN gene. Thus far a variety of mutations have been reported; however, the unique characteristics of BHD syndrome-related FSP are still unclear.

METHOD

We reviewed the family history of a large Chinese family that presented with FSP. Genetic testing of the FLCN gene was performed and the special clinical characteristics of BHD syndrome-related FSP were discussed.

RESULTS

This family comprised 5 generations and 76 members. Six of these had experienced pneumothorax episodes and 35 members had undergone genetic analysis of the FLCN gene, except for one member who had pneumothorax. Among the 35 members, 17 had the mutation in the FLCN gene. All five members with pneumothorax had the mutation. Frequency of pneumothorax in the mutation members was 29.4% (5/17). Clinical characteristics of the BHD syndrome-related pneumothorax differed from those of primary spontaneous pneumothorax, which typically affects tall, thin young men, and the recurrence rate of BHD syndrome-related pneumothorax after observation, needle aspiration or tube drainage was higher than that of primary spontaneous pneumothorax, and higher than that observed after VATS bullectomy and mechanical pleurodesis.

CONCLUSIONS

We reported the largest single family that presented with FSP from China. The clinical and genetic characteristics of the BHD syndrome-related pneumothorax differ from those of primary spontaneous pneumothorax.

Pneumothorax in a young man with anorexia nervosa

Primary spontaneous pneumothorax (PSP) is defined as a pneumothorax that occurs in the absence of an external cause in an individual without underlying generalized lung disease. A number of factors are important and should be carefully considered in the pathogenesis of PSP. This is the first case report of a PSP in a severely malnourished adolescent male with anorexia nervosa (AN) who was involved in excessive physical activity. Clinicians caring for adolescents with AN and vigorous exercise need to be aware of the risk factors associated with the development of a PSP. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2016; 49:895-898).

A rapid NGS strategy for comprehensive molecular diagnosis of Birt-Hogg-Dubé syndrome in patients with primary spontaneous pneumothorax

Background

Primary spontaneous pneumothorax (PSP) or pulmonary cysts is one of the manifestations of Birt-Hogg-Dube syndrome (BHDS) that is caused by heterozygous mutations in FLCN gene. Most of the mutations are SNVs and small indels, and there are also approximately 10 % large intragenic deletions and duplications of the mutations. These molecular findings are generally obtained by disparate methods including Sanger sequencing and Multiple Ligation-dependent Probe Amplification in the clinical laboratory. In addition, as a genetically heterogeneous disorder, PSP may be caused by mutations in multiple genes include FBN1, COL3A1, CBS, SERPINA1 and TSC1/TSC2 genes. For differential diagnosis, these genes should also be screened which makes the diagnostic procedure more time-consuming and labor-intensive.

Methods

Forty PSP patients were divided into 2 groups. Nineteen patients with different pathogenic mutations of FLCN previously identified by conventional Sanger sequencing and MLPA were included in test group, 21 random PSP patients without any genetic screening were included in blinded sample group. 7 PSP genes including FLCN, FBN1, COL3A1, CBS, SERPINA1 and TSC1/TSC2 were designed and enriched by Haloplex system, sequenced on a Miseq platform and analyzed in the 40 patients to evaluate the performance of the targeted-NGS method.

Results

We demonstrated that the full spectrum of genes associated with pneumothorax including FLCN gene mutations can be identified simultaneously in multiplexed sequence data. Noteworthy, by our in-house copy number analysis of the sequence data, we could not only detect intragenic deletions, but also determine approximate deletion junctions simultaneously.

Conclusions

NGS based Haloplex target enrichment technology is proved to be a rapid and cost-effective screening strategy for the comprehensive molecular diagnosis of BHDS in PSP patients, as it can replace Sanger sequencing and MLPA by simultaneously detecting exonic and intronic SNVs, small indels, large intragenic deletions and determining deletion junctions in PSP-related genes.

An in silico framework for integrating epidemiologic and genetic evidence with health care applications: ventilation-related pneumothorax as a case illustration

OBJECTIVE

To illustrate an in silico integration of epidemiologic and genetic evidence that is being developed at the Center for Devices and Radiological Health/US Food and Drug Administration as part of regulatory research on postmarket device performance. In addition to using conventional epidemiologic evidence from registries, this innovative approach explores the vast potential of open-access omics databases for identifying genetic evidence pertaining to devices.

MATERIAL AND METHODS

A retrospective analysis of Agency for Healthcare Research and Quality (AHRQ)/Healthcare Cost and Utilization Project (HCUPNet) data (2002-2011) was focused on the ventilation-related iatrogenic pneumothorax (Vent-IP) outcome in discharges with mechanical ventilation (MV) and continuous positive airway pressure (CPAP). The derived epidemiologic evidence was analyzed in conjunction with pre-existing genomic data from Gene Expression Omnibus/National Center for Biotechnology Information and other databases.

RESULTS

AHRQ/HCUPNet epidemiologic evidence showed that annual occurrence of Vent-IP did not decrease over a decade. While the Vent-IP risk associated with noninvasive CPAP comprised about 0.5%, the Vent-IP risk due to longer-term MV reached 2%. Along with MV posing an independent risk for Vent-IP, female sex and white race were found to be effect modifiers, resulting in the highest Vent-IP risk among mechanically ventilated white females. The Vent-IP risk was also potentiated by comorbidities associated with spontaneous pneumothorax (SP) and fibrosis. Consistent with the epidemiologic evidence, expression profiling in a number of animal models showed that the expression of several collagens and other SP/fibrosis-related genes was modified by ventilation settings.

CONCLUSION

Integration of complementary genetic evidence into epidemiologic analysis can lead to a cost- and time-efficient discovery of the risk predictors and markers and thus can facilitate more efficient marker-based evaluation of medical product performance.

Recurrent spontaneous pneumothoraces and bullous emphysema. A novel mutation causing Birt-Hogg-Dube syndrome

Birt-Hogg-Dube syndrome (BHDS) is a rare form of classically cystic lung disease that may present with spontaneous pneumothorax. The associated skin manifestations (fibrofolliculomas) are not always present. This article describes a case of spontaneous pneumothorax secondary to bullous emphysema in an otherwise healthy gentleman caused by a novel mutation in the folliculin (FLCN) gene.

A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment

DISCLAIMER

The practice guidelines of the American College of Medical Genetics and Genomics (ACMG) and the National Society of Genetic Counselors (NSGC) are developed by members of the ACMG and NSGC to assist medical geneticists, genetic counselors, and other health-care providers in making decisions about appropriate management of genetic concerns, including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice-based issue and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the ACMG and NSGC joint practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are current only as of their publication date, and are subject to change without notice as advances emerge. In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments, and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health-care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population. Practice guidelines are published by the ACMG or the NSGC for educational and informational purposes only, and neither the ACMG nor the NSGC "approve" or "endorse" any specific methods, practices, or sources of information.Cancer genetic consultation is an important aspect of the care of individuals at increased risk of a hereditary cancer syndrome. Yet several patient, clinician, and system-level barriers hinder identification of individuals appropriate for cancer genetics referral. Thus, the purpose of this practice guideline is to present a single set of comprehensive personal and family history criteria to facilitate identification and maximize appropriate referral of at-risk individuals for cancer genetic consultation. To develop this guideline, a literature search for hereditary cancer susceptibility syndromes was conducted using PubMed. In addition, GeneReviews and the National Comprehensive Cancer Network guidelines were reviewed when applicable. When conflicting guidelines were identified, the evidence was ranked as follows: position papers from national and professional organizations ranked highest, followed by consortium guidelines, and then peer-reviewed publications from single institutions. The criteria for cancer genetic consultation referral are provided in two formats: (i) tables that list the tumor type along with the criteria that, if met, would warrant a referral for a cancer genetic consultation and (ii) an alphabetical list of the syndromes, including a brief summary of each and the rationale for the referral criteria that were selected. Consider referral for a cancer genetic consultation if your patient or any of their first-degree relatives meet any of these referral criteria.

Pulmonary manifestations of Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé syndrome (BHD) is a rare, autosomal dominant disorder characterized by the development of hair follicle tumors, renal tumors and pulmonary cysts. BHD is caused by heterozygous, predominantly truncating mutations in the folliculin (FLCN) gene located on chromosome 17, which encodes a highly conserved tumor suppressor protein. Although management of renal tumors of low malignant potential is the primary focus of longitudinal care, pulmonary manifestations including cyst formation and spontaneous pneumothorax are among the most common manifestations in BHD. Due to the lack of awareness, there is commonly a delay in the pulmonary diagnosis of BHD and patients are frequently mislabeled as having chronic obstructive lung disease, emphysema or common bullae/blebs. A family history of pneumothorax is present in 35 % of patients with BHD. Certain imaging characteristics of the cysts, including size, basilar and peripheral predominance, perivascular and periseptal localization, and elliptical or lentiform shape can suggest the diagnosis of BHD based on inspection of the chest CT scan alone. Recurrent pneumothoraces are common and early pleurodesis is recommended. A better understanding of role of FLCN in pulmonary cyst formation and long term studies to define the natural history of the pulmonary manifestations of BHD are needed.

A combination of predispositions and exposures as responsible for acute eosinophilic pneumonia

BACKGROUND

Acute eosinophilic pneumonia (AEP) is a rare febrile illness which is characterized by respiratory failure and often requires mechanical ventilation. The causes and sequence of events of this disease at a biochemical and histological level remain largely unknown. In this article we report the exceptional case, possibly unique, of a patient who developed AEP and three pneumothoraces within less than one month during her hospitalization.

CASE PRESENTATION

A 39-year-old German woman was admitted to our hospital for a laparoscopy-assisted vaginal hysterectomy under general anaesthesia. The surgical intervention was followed by peritonitis in the early postoperative course. Following anaesthesia induction with propofol/midazolam and during the prolonged therapy with several broad-spectrum antibiotics, she developed AEP and three spontaneous (one left-sided and two right-sided) pneumothoraces, the latter ones observed in quick succession. Symptoms, laboratory markers, and chest radiology significantly improved after a one-day treatment with methylprednisolone.

CONCLUSIONS

On the whole, these pathological occurrences, together with similar cases reported in literature, can support the conclusion of possible predisposing genetic factors at the lung tissue level of AEP patients, a view that might shed new light on the pathogenesis of this disease. To provide a coherent pattern that explains the reported evidence for AEP and pneumothoraces, independently from the causative stimulus, the supposed molecular mutations could be localized in the connective tissue rather than in the epithelial cells. In order to interpret clinical and laboratory evidence, as well as to support the main conclusions, the important part of scientific research here presented can also assist physicians in making more informed decisions for the treatment of patients with pulmonary infiltrates.

Distinguishing the histological and radiological features of cystic lung disease in Birt-Hogg-Dubé syndrome from those of tobacco-related spontaneous pneumothorax

AIMS

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominantly inherited genodermatosis that predisposes to cystic lung disease, leading to spontaneous pneumothoraces. This retrospective analysis of five BHD cases (two men, three women) compared lung histology and computed tomography (CT) imaging to a matched cohort of non-BHD patients with spontaneous pneumothoraces (SPN).

METHODS AND RESULTS

Lung was sampled during pleurodesis to resect bullae. Recurrent pneumothoraces was seen in two patients. Fourteen sets of histological slides (seven in each group) and 10 CT scans (five in each group) were reviewed. CT scans in BHD showed multiple cysts with a basal predominance and intraparenchymal/peribronchial distribution. On histological examination, BHD lungs showed punch-out cysts with no inflammation, and lacked subpleural fibroelastotic scars and smoking changes. In contrast, all SPN cases showed respiratory bronchiolitis and subpleural fibroelastotic scars.

CONCLUSIONS

This study emphasizes the importance of smoking history and topography of the lesions in assessing cystic lung disease. Pathologists need to remain alert to the possibility of BHD in the setting of recurrent pneumothoraces in a non-smoker, in particular in a woman, at any age, and should take part in a multidisciplinary approach to the diagnosis of cystic lung disease to obtain clinical and CT scan details.

Chest wall deformity found in patients with primary spontaneous pneumothorax

BACKGROUND

the current consensus is that primary spontaneous pneumothorax frequently occurs in young male patients who are tall and thin. However, upon careful observation, many chest wall deformities have been recognized in primary spontaneous pneumothorax patients. We investigated the distinctive features of the chest wall configuration of primary spontaneous pneumothorax patients by comparing them with controls (normal and Marfan syndrome patients).

METHODS

the anteroposterior and transverse diameters of the bilateral hemithoraxes of each patient at predetermined levels were measured by computed tomography. The asymmetry, which was based on the right/left anteroposterior and right/left transverse diameter ratio, and thickness based on the anteroposterior/transverse ratio, were examined.

RESULTS

severe anteroposterior asymmetry and transverse asymmetry were observed in Marfan syndrome patients, and moderate anteroposterior asymmetry and transverse asymmetry were observed in primary spontaneous pneumothorax patients in comparison with normal control patients. Primary spontaneous pneumothorax and Marfan patients showed flatter thoraxes than normal control patients.

CONCLUSIONS

primary spontaneous pneumothorax patients tend to have asymmetric and flat thoraxes. Subclinical thoracic wall deformity observed in the primary spontaneous pneumothorax group may partly contribute to alveolar pressure heterogeneity, and may be related to subpleural bleb formation.

A case of spontaneous pneumomediastinum and epidural pneumatosis in a young woman in the Emergency Department

BACKGROUND

Pneumomediastinum is a relatively rare, yet typically benign, clinical condition that usually presents in young men.

OBJECTIVE

This report will describe a relatively rare event of pneumomediastinum with epidural extension in a young woman and will discuss the etiology, clinical manifestations, and treatment options for this condition.

CASE REPORT

The patient presented to the Emergency Department (ED) with typical symptoms of shortness of breath and chest pain, but was found on computed tomography to have epidural pneumatosis. No precipitating event was found.

CONCLUSION

This case of spontaneous pneumomediastinum with associated epidural pneumatosis in a young woman presenting to the ED is a relatively benign condition that typically does not require any significant work-up or treatment.

Pediatric bilateral spontaneous pneumothoraces in monozygotic twins

Primary spontaneous pneumothorax from subpleural bleb disease is an uncommon occurrence in pediatric patients. This is a rare case of monozygotic twins presenting at alternating intervals with a single-sided spontaneous pneumothorax, only to have it surgically corrected, and to present later with a subsequent contralateral pneumothorax. A review of familial spontaneous pneumothoraces occurring in children was queried for congenital or genetic syndromes. We concluded that a vast majority of pneumothoraces in children, like adults, are not spontaneous and not familial linked. While they are rare, some congenital syndromes have been identified. The HLA haplotype A2 B40, the gene encoding folliculin, Alph-1-antitrypsin, Marfan's syndrome, Ehlers-Danlos syndrome and Birt-Hogg-Dube syndrome have all been associated with familial spontaneous pneumothoraces. Physicians need to counsel family members to ensure appropriate observation and expedited treatment is not delayed.

Pleural controversy: aetiology of pneumothorax

Pneumothoraces are classified as spontaneous, traumatic and iatrogenic. Spontaneous pneumothoraces that occur without recognized lung disease are termed primary spontaneous pneumothoraces (PSP), whereas those that occur due to an underlying lung disease are termed secondary spontaneous pneumothoraces. The aetiology of secondary, traumatic or iatrogenic pneumothoraces is not usually debated. However, the aetiology of PSP is potentially controversial and often debated. Therefore, PSP is the focus of this article. There are several purported causes, which include blebs, bullae, emphysema-like changes (ELC) and pleural porosity. The controversy is valid because of the importance of recurrence prevention. This article reviews the current available evidence for the causes of PSP. The causes of PSP are likely a combination ELC, pleural porosity and other potential factors.

A Japanese family with multiple lung cysts and recurrent pneumothorax: a possibility of Birt-Hogg-Dubé syndrome

We herein report a Japanese family lineage, possibly demonstrating Birt-Hogg-Dubé (BHD) syndrome. A 29-year-old nonsmoking woman was admitted to our hospital due to spontaneous pneumothorax. A chest CT showed multiple lung cysts, and breast cancer was simultaneously detected that needed priority surgical treatment. In the family history, the patient's father and half brother also experienced recurrent pneumothorax, and both had similar findings in their chest CT. In a genetic analysis of her half brother, the mutation of the BHD gene was identified. BHD syndrome is a rare autosomal and dominantly inherited disorder, which has three characteristics: multiple lung cysts that may be associated with pneumothorax, skin fibrofolliculomas, and renal neoplasm. For multiple-cystic disease of the lungs with an unknown etiology, or pneumothorax, as seen in a family history, it is necessary to consider the possibility of BHD syndrome.

Folliculin mutations are not associated with severe COPD

Background

Rare loss-of-function folliculin (FLCN) mutations are the genetic cause of Birt-Hogg-Dubé syndrome, a monogenic disorder characterized by spontaneous pneumothorax, fibrofolliculomas, and kidney tumors. Loss-of-function folliculin mutations have also been described in pedigrees with familial spontaneous pneumothorax. Because the majority of patients with folliculin mutations have radiographic evidence of pulmonary cysts, folliculin has been hypothesized to contribute to the development of emphysema.

To determine whether folliculin sequence variants are risk factors for severe COPD, we genotyped seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax associated folliculin mutations in 152 severe COPD probands participating in the Boston Early-Onset COPD Study. We performed bidirectional resequencing of all 14 folliculin exons in a subset of 41 probands and subsequently genotyped four identified variants in an independent sample of345 COPD subjects from the National Emphysema Treatment Trial (cases) and 420 male smokers with normal lung function from the Normative Aging Study (controls).

Results

None of the seven previously reported Birt-Hogg-Dubé or familial spontaneous pneumothorax mutations were observed in the 152 severe, early-onset COPD probands. Exon resequencing identified 31 variants, including two non-synonymous polymorphisms and two common non-coding polymorphisms. No significant association was observed for any of these four variants with presence of COPD or emphysema-related phenotypes.

Conclusion

Genetic variation in folliculin does not appear to be a major risk factor for severe COPD. These data suggest that familial spontaneous pneumothorax and COPD have distinct genetic causes, despite some overlap in radiographic characteristics.