Lung cysts, spontaneous pneumothorax, and genetic associations in 89 families with Birt-Hogg-Dubé syndrome

RATIONALE

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal, dominantly inherited genodermatosis that predisposes to fibrofolliculomas, kidney neoplasms, lung cysts, and spontaneous pneumothorax.

OBJECTIVES

We evaluated 198 patients from 89 families with BHDS to characterize the risk factors for pneumothorax and genotype-pulmonary associations.

METHODS

Helical computed tomography scans of the chest were used to screen for pulmonary abnormalities. BHD mutation data were used for genotype-pulmonary associations. We examined the relationship of pneumothorax with categorical parameters (sex, smoking history, and lung cysts) and continuous parameters (number of cysts, lung cyst volume, and largest cyst diameter and volume). Logistic regression analyses were used to identify the risk factors associated with pneumothorax.

MEASUREMENTS AND MAIN RESULTS

Twenty-four percent (48/198) of patients with BHDS had a history of pneumothorax. The presence of lung cysts was significantly associated with pneumothorax (p = 0.006). Total lung cyst volume, largest cyst diameter and volume, and every parameter related to the number of lung cysts were significantly associated (p < 0.0001) with pneumothorax. A logistic regression analysis showed that only the total number of cysts in the right parenchymal lower lobe and the total number of cysts located on the pleural surface in the right middle lobe were needed to classify a patient as to whether or not he or she was likely to have a pneumothorax. Exon location of the BHD mutation was associated with the numbers of cysts (p = 0.0002).

CONCLUSIONS

This study indicates that patients with BHDS have a significant association between lung cysts and spontaneous pneumothorax.

Congenital malformations of the lung

Congenital malformations of the lung are rare and vary widely in their presentation and severity. The most common manifestation of the congenital cystic disease of the lung at newborn and early infancy is respiratory distress. Later on in life, cysts usually lose this compressive character and may remain asymptomatic until infection occurs, while producing cough, dyspnea and thoracic pain. The purpose of this study is to review authors institutional experience of congenital cystic lung disease, with specific reference to diagnosis, treatment, as well as outcome, furthermore, to present some cases with unusual clinical manifestations.

Surgical management of mediastinal lesions

Mediastinal tumors and cysts are relatively uncommon lesions requiring histologic confirmation. This retrospective study reports the experience of our department in the diagnosis and treatment of mediastinal lesions. Mediastinal lesions that were surgically treated in 200 patients aged 6-84 years, during a period of 28 years, were included in this series. Sixty patients had an apparently non-resectable lesion or lymphadenopathy of the anterior superior mediastinum. They had an anterior mediastinotomy and biopsy of the mediastinal lesion. No perioperative deaths were recorded in those patients. There were recorded 5 (8.3%) complications. Histological diagnosis was established in all patients: lymphoma (n = 21), metastatic carcinoma (n = 16), thymic lesions (n = 10), germ cell tumor (n = 3), other lesions (n = 10). The remainder 140 patients underwent a resection of the mediastinal lesion. One (0.7%) perioperative death and 21 (15%) complications were recorded. The histological diagnosis of the excised lesions was: thymic lesions (n = 60), neural tumors (n = 21), thyroid lesions (n = 14), bronchial cysts (n = 12), pericardial cysts (n = 10), germ cell tumors (n = 6), other lesions (n = 17). Our results are compared favorably with those reported in international literature. Surgery is the management of choice for patients with mediastinal lesions. It allows for establishing certain histological diagnosis and curative excision of the lesion, when it is necessary, with low operative risk.

Subdiaphragmatic bronchogenic cysts: a comprehensive review of the literature

Bronchogenic cysts are foregut-derived developmental anomalies most commonly encountered in the mediastinum and rarely in the abdomen or retroperitoneally. A comprehensive review of the English-language literature of subdiaphragmatic bronchogenic cysts (sBCs) revealed only 48 reported cases of sBC. Although most cases are incidentally discovered, preoperative differential diagnosis often includes tumors with malignant potential and necessitates surgical resection to obtain a definitive diagnosis. Herein, we describe a case of a 46-year-old female presenting with intermittent left flank pain, upon which computed tomography demonstrated a retroperitoneal mass. Upon resection, histopathology revealed the mass to be a thin-walled cystic mass lined by ciliated columnar cells and cartilage, consistent with a subdiaphragmatic bronchogenic cyst. A comprehensive literature review of sBC was also performed.

Outcome predictors for infants with cystic lung disease

BACKGROUND/PURPOSE

This study aimed at identifying characteristic features indicating congenital cystic adenomatoid malformation of the lung (CCAM) and evaluating the outcome predictors to identify prenatally subgroups of fetuses with significantly different probabilities of mortality or severe respiratory difficulty.

METHODS

Twenty-eight neonates who had undergone antenatal evaluation for cystic lung disease (CLD) were reviewed retrospectively. The patients were divided into 3 groups according to the severity of their clinical course; mild (n = 7), moderate (n = 13), and severe (n = 8). Ultrasonographic findings in the fetus and their pulmonary lesion were evaluated. The normal lung to thorax transverse area ratio (L/T) was measured by ultrasonography.

RESULTS

High echogenicity of the lesion throughout pregnancy and polyhydramnios were frequently seen in CCAM. All of the patients with other CLD showed isoechogenicity at the end of pregnancy. All patients in the severe group had both polyhydramnios and fetal hydrops. L/T was increased in mild and moderate groups, whereas no patient in the severe group had an increase in L/T at the final measurement. Each value of final L/T in the severe group was less than 0.25.

CONCLUSIONS

The subgroup of fetuses with an increased probability of mortality or severe respiratory difficulty could be predicted from the combination of polyhydramnios, fetal hydrops, and a final L/T value of less than 0.25.

Lung cysts in subacute hypersensitivity pneumonitis

PURPOSE

To determine the frequency of cystic lesions on high-resolution computed tomography (CT) in patients with subacute hypersensitivity pneumonitis.

METHODS

High-resolution CT scans in 182 patients with proven subacute hypersensitivity pneumonitis were retrospectively evaluated for the presence of lung cysts. Patients with CT evidence of emphysema or interstitial fibrosis and patients with connective tissue disease were excluded from the study. Two thoracic radiologists reviewed the thoracic CT scans for the presence and location of lung cysts.

RESULTS

Thin-walled lung cysts were identified in 24 (13%) of 182 patients and ranged in size from 3 to 25 mm in maximal diameter. The patients included 16 men and 8 women (age range, 30-79 years; mean age, 48 years). The cysts ranged from 1 to 15 in number (mean, 4 cysts) and had a random distribution. Sixteen of the 24 patients also had areas of decreased attenuation and vascularity consistent with air trapping.

CONCLUSIONS

Thin-walled cysts can be seen in a small percentage of patients with subacute hypersensitivity pneumonitis. The cysts resemble those seen in lymphocytic interstitial pneumonia, and their pathogenesis is uncertain.

[Air-filled cysts of tracheal origin: nosological problems and actual frequency]

Air-filled paratracheal bronchogenic cysts are extremely rare. They are lined by respiratory epithelium. We have operated on 2 patients whose cysts were diagnosed by CT scan: one presenting with bloody sputum and the other with dysphagia. Both patients had a history of neck surgery. Because such cases are rare in the literature, their exact origin, whether tracheocele, diverticulum or other form of air-filled cyst, remains a matter of debate. However, their frequency is probably underestimated because most cause few symptoms and are well tolerated. In a recent radiologic study their prevalence was found to be 2% in patients undergoing CT scan.

Complications of the naevoid basal cell carcinoma syndrome: results of a population based study

There are many potential complications which have been reported in association with the naevoid basal cell carcinoma syndrome. We have been able to show the relative frequencies of these problems in a population based study of 84 cases in the north west of England. The major complications of basal cell carcinomas and jaw cysts occur in over 90% of patients by 40 years of age, but may both occur before 10 years of age. Less well described complications are ovarian calcification or fibroma (24%), medulloblastoma (5%), cardiac fibroma (3%), cleft palate (5%), and ophthalmic abnormalities such as squint or cataract (26%). This study more clearly defines the possible complications of the syndrome and gives clearer guidelines for counselling and screening affected and at risk persons.

[A case of paraesophageal bronchogenic cyst with esophageal communication]

A case of mediastinal bronchogenic cyst communicating with the esophagus was reported. Previously, only 2 cases have been reported in the available literature. A 34-year-old man was admitted with a cystic mass communicating with the esophagus which was demonstrated on a barium study. Operation was performed with a suspect of esophageal diverticulum or congenital cyst with esophageal communication. At right thoracotomy, a mass measuring 6.0 x 5.0 cm with a well-defined patent communication to the esophagus was resected. It was a monolocular cyst containing a small amount of viscous mucus. Histologically, the cyst lined by a ciliated columnar epithelium, and it was diagnosed as a bronchogenic cyst because of the presence of the mucous glands, smooth muscle tissue and cartilage. This is the first case report of mediastinal bronchogenic cyst with esophageal communication appeared in the Japanese literature.

[Two successful cases of paraesophageal bronchogenic cysts]

Paraesophageal bronchogenic cyst is a rare disease. Only 24 cases have been previously reported in Japan. Recently, we experienced two successful cases of this disease. Two cases (64-year-old man and 31-year-old man) were both asymptomatic and pointed out by chance on the chest X-ray at the left posterior mediastinum. The second case was an intramural esophageal cyst. Microscopic examination showed the typical findings of the bronchogenic cyst, as the inner wall of the cyst was covered with ciliated columnar epithelium and the wall consisted of cartilage, mucous glands and smooth muscle. Both postoperative courses were uneventful. Resection was recommended because of the symptoms due to the compression of the cyst and the possibility of malignancy.

Primary mediastinal tumors in children

From 1950-1986, a total of 159 children (age 1 day-16 years) were treated for primary mediastinal tumors at our hospital. There were 77 malignant and 82 benign tumors. Tracheal compression causing respiratory distress was a significant symptom in 45.3% (24/53) of the children under 2 years of age. The diagnosis was based on the chest X-ray and the findings at surgery. Malignant lymphoma was usually diagnosed by cervical lymph node biopsy (23/39) but the treatment protocol was non-surgical. Non-lymphatic malignant tumors were completely or partially excised in 59.0% (23/39) of the cases. There was no early or late mortality in patients with benign tumors. At follow-up (0.5-24 years; mean 6.0 years), 62.3% (48/77) of the patients with malignant tumors were alive and symptom free. About half of the mediastinal tumors in children are malignant. Mediastinal tumors in small children can cause severe respiratory symptoms demanding urgent treatment. The treatment of choice is surgery (except in lymphomas) and the results are good even in malignant tumors.