Clinical spectrum of congenital cystic disease of the lung in children 1

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1 European Journal of Cardio-thoracic Surgery 15 (1999) Clinical spectrum of congenital cystic disease of the lung in children 1 Shin-ichi Takeda*, Shinichiro Miyoshi, Masayoshi Inoue, Ken-ichi Omori, Meinoshin Okumura, Hyung-Eun Yoon, Masato Minami, Hikaru Matsuda First Department of Surgery, Osaka University Medical School, 2-2 Yamada Oka, Suita City, Osaka 565, Japan Received 29 December 1997; received in revised form 28 September 1998; accepted 28 October 1998 Abstract Objectives: Congenital cystic lesions of the lung are uncommon but share similar embryologic and clinical characteristics. The purpose of this study is to review our institutional experience of congenital cystic lung disease, emphasizing the clinical spectrum of the disease related to age, and present some cases with unusual clinical manifestations. Patients: Between 1962 and 1996, 26 patients (9 females and 17 males) under 15 years old underwent evaluation and surgical treatment for congenital cystic lung disease. Seven patients were under 1 year old, and 19 were in over 1 year old. There were 13 bronchogenic pulmonary cysts, 6 pulmonary sequestrations, 4 congenital cystic adenomatoid malformations (CCAM), and 3 congenital lobar emphysemas. Results: All patients under 1 year old showed respiratory distress with mediastinal shift but no episodes of infection. In contrast, 13 of the 19 patients over 1 year old had symptoms of recurrent infection without respiratory distress. Five patients over 1 year old were entirely asymtomatic from birth. There were significant differences (P 0.05) in the frequencies of respiratory distress and infection between the two groups (x 2 -test). Lobectomy was performed in 21 patients, excision in 3 patients, segmentectomy in one patient, and exploration in one patient. There was no incident of postoperative mortality or morbidity except for one patient with CCAM complicated by reexpansion lung edema. Twenty-one patients at long-term follow-up from 2 to 30 years after surgery are doing well with no subsequent limitation of physical activities due to lung resection. Conclusions: In patients under 1 year old, cystic lesions were discovered by respiratory distress; and in patients over 1 year old signs of infection were the most important clinical features. Early recognition of these relatively rare congenital cystic lung lesions would lead to the immediate, proper surgical intervention Elsevier Science B.V. All rights reserved. Keywords: Congenital cystic lung disease; Bronchopulmonary foregut malformation 1. Introduction Congenital cystic lesion of the lung in children is uncommon but potentially life-threatening, and warrants an urgent diagnostic work-up [1 4]. These diseases may result from compromised interaction between embryologic mesodermal and ectodermal lung components during development. Pulmonary sequestration, congenital cystic adenomatoid malformation (CCAM), congenital lobar emphysema, and * Corresponding author. Tel.: ; fax: ; stakeda@surg1.med.osaka-u.ac.jp 1 Presented in part at the Annual Assembly of the American Thoracic Society, New Orleans, LA, USA, May 10 15, bronchogenic pulmonary cysts are major four congenital cystic lesions in the lung, but share similar embryologic and clinical characteristics [1,4]. These disease entities are also named as bronchopulmonary foregut malformations. The first successful surgical removal was noted in 1933 by Reinhoff et al. [5] for a lung cyst in the right upper lobe in a 3-year-old boy. With the improved safety of pediatric anesthesia and the development of non-invasive diagnostic procedures, thoracic surgery for symptomatic cystic lesions of the lung has advanced as well as the awareness of these anomalies among pediatricians. This report retrospectively reviews our institutional experience of congenital cystic lung disease, emphasizing the clinical spectrum of the disease related to age, and some case presentations with unusual clinical manifestations /99/$ - see front matter 1999 Elsevier Science B.V. All rights reserved. PII: S (98)

2 12 S. Takeda et al. / European Journal of Cardio-thoracic Surgery 15 (1999) Patients and methods Between 1962 and 1996, 368 patients under 15 years old with thoracic surgical conditions underwent evaluation and surgical treatment in the Department of Surgery of the Osaka University Medical School. The hospital records of these patients were reviewed. Chest wall deformity including funnel chest and pigeon chest was the most common condition, observed in 136 (37.0%) patients, and mediastinal tumor was noted in 117 (31.8%) patients. Congenital cystic disease of the lung was seen in 26 patients (7.1%). Of these 26 patients, 9 were females and 17 were males, ranging in age from birth to 14 years old. Seven patients were under 1 year old, and 19 were over 1 year old. There were 13 bronchogenic pulmonary cysts (1 1 year, 12 1 year), 6 pulmonary sequestrations (1 1 year, 5 1 year), 4 congenital cystic adenomatoid malformations (CCAM) (2 1 year, 2 1 year), and 3 congenital lobar emphysemas (3 1 year, 0 1 year). One patient with CCAM also had a lesion of pulmonary sequestration. We compared clinical manifestations between the patients under 1 year old and those over 1 year of age. Diagnostic studies included standard chest X-rays and computed tomography (CT) scans, aided by selective use of angiography. Magnetic resonance imaging (MRI) was performed to confirm the diagnosis and to better characterize the cystic content in recent series. Surgical therapy was mainly indicated with based on the symptom of respiratory distress and episodes of infection in addition to the clinical diagnosis of congenital cystic disease of the lung. 3. Results Table 1 shows the clinical profiles of the patients with congenital cystic disease of the lung under 1 year of age, including bronchogenic pulmonary cyst (BC), congenital cystic adenomatoid malformation (CCAM), congenital lobar emphysema (CLE) and pulmonary sequestration (PS). Two patients with BC under 1 year old had symptoms with respiratory distress. Patient #1 had the symptom of respiratory distress associated with acute mediastinal shift due to a ballooning of the cyst (Fig. 1); emergency left lower lobectomy was performed. In this case, communication between the airway and cyst might have caused the check-valve phenomenon resulting in ballooning of the tumor. There were 2 patients with CCAM and 3 with CLE under 1 year old. Patient #2 was referred to our hospital because of respiratory distress with apparent mediastinal shift on chest X-ray film (Fig. 2A). This case was categorized in an early series, and emergency right middle lobectomy was performed with a diagnosis of bronchogenic cyst. A histopathological diagnosis of CCAM (Stocker type I) was obtained, and the patient needed mechanical ventilation 2 days after surgery because of reexpansion due to pulmonary edema of the right lower lobe. Patient #3 had severe respiratory distress and required mechanical ventilation from birth, and emergency left upper lobectomy was performed after a diagnosis of CCAM, with symptomatic improvement. Histology showed a Stocker type III lesion of CCAM. All 3 patients with CLE, under 1 year of age, were seen in our early series. Patient #4 exhibited stridor from birth and chest X-ray and angiography revealed situs inverusus (Fig. 2B). Thoracotomy revealed a grossly overdistended left middle lobe, but operative resection was abandoned since the upper and lower lobes were extremely hypoplastic. This patient therefore showed little symptomatic improvement after the exploratory thoracotomy. However, gradual resolution with symptomatic improvement was observed during somatic growth. A marked mediastinal shift with hyperaeration of the affected lobe was identified in Patients #5 and #6 with significant respiratory distress. These patients were treated by upper segmentectomy and right lobectomy with complete cure of the symptom. Examination of the resected lobes revealed marked emphysema with overinflation of the alveoli and destruction of alveolar septa. There were 2 extralobar and 4 intralobar pulmonary sequestration (PS) cases in the present pediatric population. One patient with PS under 1 year of age who underwent surgical intervention at our institution had an extremely rare condition. This patient (#7) was a 6-month-old female who had showed stridor and cough since she was 4 months old. Her right thorax was occupied by anomalous lung and dex- Table 1 Clinical profiles of the patients (under 1 year old) Case Age/sex Disease Symptom (I MS D) Treatment, remarks 1 3 months/f BC + ( + +) Emergency LLL 2 5 months/m CCAM I + ( + +) RML, reexpansion lung edema 3 3 days/m CCAM III + ( + +) Emergency LUL 4 7 months/f CLE + ( + +) Exploration 5 3 months/f CLE + ( + +) Segmentectomy 6 7 months/m CLE + ( + +) RUL 7 7 months/f EPS + ( + +) Excision, celiac artery blood supply I, infection; MS, mediastinal shift; D, dyspnea; RUL, right upper lobectomy; RML, right middle lobectomy; LUL, left upper lobectomy; LLL, left lower lobectomy; BC, bronchogenic pulmonary cyst; CCAM, congenital cystic adenomatoid malformation; CLE, congenital lobar emphysema; EPS, extralobar pulmonary sequestration.

3 S. Takeda et al. / European Journal of Cardio-thoracic Surgery 15 (1999) Fig. 1. Patient #1 had a symptom of respiratory distress associated with acute mediastinal shift due to ballooning of the cyst; emergent left lower lobectomy was performed. trotated heart instead of the normal right lung. (Fig. 3, left). Several investigative procedures disclosed an abnormal lung that communicated with esophagus (Fig. 3, right) and had a systemic arterial supply from the abdominal aorta without right pulmonary artery. Resection of the abnormal lung was performed without complication; the patient gradually recovered and is developing well 8 years after surgery. This anomaly seemed to be classifiable as extralobar sequestration without normal left lung, i.e. as one feature of lung bud foregut anomaly. Table 2 shows clinical profiles of the patients with congenital cystic disease of the lung over 1 year of age. Ten of 12 patients with BC over 1 year of age had a history of repeated infection and cough, but none showed respiratory distress. In Patient #11, the bronchogenic cyst was discovered by an episode of infection after surgical correction of the funnel chest. Two patients were entirely asymptomatic and found in the annual check-up at school. In 11 of the 12 patients, surgery was recommended and performed as soon as the malformation was found. In Patient #10, surgical treatment was arranged after the finding that the cyst increased in size 1 year after the initial check-up. Nine patients underwent lobectomy, and in one patient excision of the cyst located in the periphery was performed. All patients are doing well after surgery without infectious signs; however, Patient #15 (Fig. 4), even though asymptomatic, required chemotherapy for tuberculosis since a histologically distinctive caseous lesion was found on the cyst wall. The symptom of CCAM in patients over 1 year old was silent. The cystic lesion of a 2-year-old male with CCAM (#20) was discovered by the examination for recurrent pulmonary infection following repair of funnel chest. A 14- year-old female (#21) with CCAM and extralobar pulmonary sequestration was asymptomatic from birth. The patient s hyperlucent area in the right lower lung field was identified in the annual check-up at school. After a diagnosis of lung tuberculosis, chemotherapy was initiated without any improvement of the abnormal shadow. Chest CT revealed a multicystic area in the right lower lobe, and operative lobectomy was done after the diagnosis of cystic Table 2 Clinical profiles of the patients (over 1 year old) Case Age/sex Disease Symptom (I MS D) Treatment, remarks 8 8 years/m BC ( ) RLL 9 8 years/m BC + (+ ) RMLL 10 a 9 years/m BC ( ) LUL 11 8 years/m BC + (+ ) RUL 12 8 years/m BC + (+ ) RUL 13 7 years/m BC + (+ ) RLL 14 8 years/m BC + (+ ) RLL 15 2 years/f BC + (+ ) RUL 16 5 years/m BC + (+ ) Excision years/m BC + (+ ) RLL, funnel chest 18 6 years/f BC + (+ ) RLL 19 7 years/m BC + (+ ) RLL 20 2 years/m CCAM I ( ) LLL, funnel chest 21 b 14 years/f CCAM I, EPS ( ) RLL, systemic artery blood supply years/m IPS + (+ ) LUL, intercostal artery blood supply 23 5 years/m IPS + (+ ) RLL, intercostal artery blood supply years/m IPS + (+ ) RLL, bronchial artery blood supply 25 5 years/f IPS + (+ ) LLL, intercostal artery blood supply 26 7 years/m EPS ( ) Excision, systemic artery blood supply I, infection; MS, mediastinal shift; D, dyspnea; RUL, right upper lobectomy; RMLL, right middle and lower lobectomy; RLL, right lower lobectomy; LUL, left upper lobectomy; LLL, left lower lobectomy; BC, bronchogenic pulmonary cyst; CCAM, congenital cystic adenomatoid malformation; CLE, congenital lobar emphysema; EPS, extralobar pulmonary sequestration; IPS, intralobar pulmonary sequestration. a Surgery was arranged after the finding that the cyst show increased in size 1 year after the initial check-up. b In this case, pulmonary sequestration was found during surgery for CCAM.

4 14 S. Takeda et al. / European Journal of Cardio-thoracic Surgery 15 (1999) lung disease. The pathological finding was consistent with CCAM as described by Kwittken et al. [6] and was classified into Stocker I. In this case, extralobar sequestration was incidentally found, which was excised simultaneously. Mediastinal shift with respiratory distress was not noted in patients with late onset of CCAM (#20 and #21) as we experienced. Four of 6 patients (66.7%) with PS over 1 year of age, including the case #21 had symptoms of recurrent infection. Intralobar sequestration (cases #22, #23, #24 and #25) had been diagnosed by the angiographic demonstration of the anomalous blood supplies and confirmed at thoracotomy. Patient #24 had a systemic blood supply from a bronchial artery communicating with a pulmonary artery. In Patients #20 and #26 with extralobar sequestrations, the lesions were found unexpectedly during thoracotomies for other diseases; CCAM for Patient #20 and thymic hyperplasia for Patient #26. Four patents with intralobar sequestrations were treated by lobectomy, and removal of the sequestrated lung was performed for 2 patients with extralobar sequestration. The postoperative courses were uneventful in all patients. To summarize the cases we experienced, all the patients under 1 year of age were symptomatic, and the major cause of respiratory distress was mediastinal shift due to the cystic lesions. In contrast, 26% of the patients over 1 year old with cystic lung disease were asymptomatic as shown in Table 3. The major clinical manifestation was infection, seen in 74% of the patients. In most of the early part of the series, chest X-ray was the only diagnostic test performed. Lobectomy was performed in 21 patients, segmentectomy was done in one patient, and excision was done in 3 patients. There was no postoperative mortality or morbidity except for one patient with CCAM who was complicated by reexpansion lung edema requiring mechanical ventilation. Twenty-one patients at long-term follow-up ranging from 2 to 30 years after surgery are doing well with no subsequent limitation of physical activities due to lung resection. 4. Discussion Fig. 2. Patient #2 was referred to our hospital because of respiratory distress with apparent mediastinal shift on chest X ray film (A, upper panel). Right middle lobectomy was performed to find histologically CCAM with Stocker type I. Patient #4 with CLE exhibited stridor from birth, and chest X-ray (B, lower panel) revealed situs inverusus. Thoracotomy found an overinflated left middle lobe. During the development of the embryo, separation of the trachea and the esophagus occurs, and migration of the early lung bud takes place. The lung tissue shows further differentiation thereafter into airway epithelium and alveolar cells. In this developmental stage, numerous abnormalities can take place [1 3]. Bronchopulmonary foregut malformations are combinations of these forms of disordered lung growth such as dysplasia, hypoplasia, or hyperplasia involving one or more structural components of the lung. In contrast, pneumatocele and unilateral hyperlucent lung [7], even though they mimic congenital cystic diseases, are regarded as being of acquired origin in their pathogenesis, and were excluded in the current series. Bronchogenic pulmonary cysts (BS) were the most common lesion in our series, and are examples of anomalies occurring early in lung development. Bronchogenic cysts might properly be called lung bud cysts, since they probably originated from embryonic bud tissue before the bronchi were formed [8,9]. They may be lined with squamous epithelium rather than respiratory epithelium, presumably due to the recurrent infection. In the current series, we used the term of bronchogenic cyst for the congenital cystic mass in the lung parenchyma. Pure mediastinal bronchogenic cysts, which can be treated by simple excision, were excluded from this study. Only one case was treated with excision, and the other cases required lobectomy. One patient at the age of 3 months required emergency lobectomy because of acute onset of expansion of the cyst associated with respiratory distress. We have not experienced complications such as tension pneumothorax or empyema due to rupture of the cyst. CCAM probably results from a cessation of bronchial maturation and concomitant overgrowth of mesenchymal elements, which produce the adenomatoid appearance of

5 S. Takeda et al. / European Journal of Cardio-thoracic Surgery 15 (1999) Fig. 3. Patient #7 was a 6-month-old female who had had stridor and cough since she was 4 months old. Her right thorax was occupied with anomalous lung and dextrotated heart instead of the right normal lung (A, left). Several investigative procedures disclosed an abnormal lung that communicated with the esophagus (A, right), absence of right pulmonary artery and had a systemic arterial supply from the abdominal aorta. This anomaly was classified as extralobar sequestration without normal left lung, or total lung ectoplasia. the anomaly in the early stage of development [1,3,4,10]. Histologically, cartilage is absent, reflecting the bronchial maldevelopment. There often exist a small bronchial communication which leads to infection and overinflation of the cystic disease. Stocker and associates [11,12] outlined the classification of these lesions based on the clinical presentation and pathologic pictures related to the lung maturity. According to the report by Bailey et al. [4], 7 out of 16 cases with CCAM had associated lesions, in which pulmonary sequestration was the most common seen in 6 out of 17 patients with CCAM. CCAM usually affects only one lobe, and when multilobar, remains unilateral. All lobes are involved with equal frequency [13]. In cases with bilobar or bilateral lesions, prognosis is known to be poor because of pulmonary hypoplasia of the residual lung [4,14,15]. With the recent advent of perinatal ultrasonography [16], it has become possible to diagnose CCAM in utero; in other words, raising the possibility of elective surgery after birth or fetal surgery for treatment of CCAM [17]. Congenital lobar emphysema (CLE) is a marked pulmonary hyperinflation state that resembles all of the clinical features of obstructive emphysema [1,4,18,19]. One possible etiology is that cartilaginous defect weakens the bronchus, which may cause collapse on expiration followed by air-block hyperinflation [4,18]. Another mechanism is that overgrowth of the alveoli, i.e. an increase in alveolar number may cause hyperinflation, as proposed by Hislop et al. [19]. It is necessary for pediatricians to evaluate associated anomalies because 14% of the cases of CLE have coexistent congenital heart disease [20]. More importantly, surgeons must differentiate acute reversible lobar emphysema from the serious irreversible lesions [18]. In our early series, we decided not to resect the hyperinflated middle lobe of Patient #4 because the other lobes seemed hypoplastic; however the patient s condition eventually improved gradually thereafter. Retrospectively, emphysematous lesions of this case seemed to be reversible lobar emphysema. It is similar to the cases reported by Kennedy et al. [21] who evaluated the patients with CLE who were treated Table 3 Clinical symptoms and signs in cystic lung disease in children (comparison between the patients under and over 1-year-old) 1-year-old 1-year-old P-value a Symptomatic 7 (100%) 14 (74%) Asymptomatic 0 (0%) 5 (26%) NS Infection (+) 0 (0%) 14 (74%) Infection ( ) 7 (100%) 5 (26%) 0.05 Mediastinal shift or dyspnea Present 7 (100%) 0 (0%) Absent 0 (0%) 19 (100%) 0.01 a x 2 -analysis.

6 16 S. Takeda et al. / European Journal of Cardio-thoracic Surgery 15 (1999) Fig. 4. Patient #15, even though asymptomatic, required chemotherapy since the histologically distinctive caseous lesion (tuberculosis) was found on the cyst wall. conservatively and found functional improvement of the affected lobe. Pulmonary sequestration (PS) probably occurs very early in the embryonic development before the pulmonary and aortic circulation become separate; and Pryce [22] clearly described the lesion as a distinct clinical entity. Sequestration could represent a separate mini-lung bud, which keeps a systemic artery and drains into either venous system depending on its intimacy with normal lung bud to which it is adjacent [1,2,15,23]. Extralobar sequestration is usually asymptomatic, and is found incidentally in the posterior part of the costphrenic angle. An intralobar pulmonary sequestration is usually located in the posterior basilar region of the lower lobe [15,23]. Children or young adults with recurrent lower lobe pneumonia should be suspected of having intralobar sequestration. An intralobar pulmonary sequestration may present rarely in the neonatal period with respiratory distress secondary to the congestive heart failure [24]. Ligation of the aberrant systemic artery supply without resection of the sequestrated lung tissue has been performed in asymptomatic or hemodynamically unstable patients [25]. However, we recommend surgical resection because there was the possibility of microscopic infection in the sequestrated lung with late occurrence of symptoms even in patients without any apparent symptom at time of surgery. Gerle et al. [26] collected 13 rare cases of pulmonary sequestration having communication with the gastrointestinal tract; and then proposed to describe this disease entity as congenital bronchopulmonary foregut malformation that includes extralobar and intralobar sequestrations. This disease entity seems to share a common embryogenesis. On the other hand, controversy still exists over the sequestration having communication with gastrointestinal tract as we experienced in Patient #7. Considering the 3 distinctive features: (1) absence of normal right lung, (2) abnormal lung tissue communicating with the esophagus, and (3) systemic blood supply into the lesion, this case was classified into lung ectoplasia according to Schechter et al. [27]. Reviewing recent reports [2,4,15], more than 50% cases with congenital cystic lesions of the lung were seen in infancy before 6 months of age. Age distribution in the current series was a little different. However, the main symptom in infancy with these anomalies was the same. Therefore we concluded that the symptoms of these patients depended on the onset of age, regardless of the type of disease. In patients under 1 year of age, cystic lesions were discovered by respiratory distress; and sign of infection was a core clinical feature in patients over 1 year of age. Since newborns and infants have a weak chest wall and mediastinum structure, the intrapulmonary expanding mass may cause tracheal bronchial compression result in respiratory distress. Presumably the patients who survive with minimum or slight respiratory distress, however, finally end suffering from recurrent infection. As to the diagnostic modality, chest X-ray was once the most cost and time efficient method of diagnosing surgical lesion, and was the only diagnostic study in our early series [9]. Nowadays, congenital cystic lung disease in children can be readily diagnosed with current imaging modalities, such as CT, MRI, and ultrasonography and digital subtraction angiography. Color Doppler sonography has recently made it possible to identify the feeding vessels non-invasively [28]. Bronchoscopy was of minimal help in determining the nature of the problem; it only helped to rule out other lesions under considerations, such as distal and aspirated foreign bodies [23]. The appropriate diagnostic test would allow for efficient treatment, avoiding complications. The plain chest X-ray serves as the starting point for diagnostic evaluation and sometimes, all modalities are needed. In addition, asymptomatic cystic lesions were sometimes found during the examination or follow-up for another anomaly as we experienced in 2 patients. Infants and children tolerate lobectomy extremely well with compensatory lung growth [29] so that total lung volume and gas exchange capacity return toward normal during somatic maturation. In an experimental study, when immature canines were raised to maturity after right pneumonectomy (55% of lung resection), compensatory lung growth returned the gas exchange and exercise performance to normal [30,31]. There was no incidence of postoperative mortality or morbidity except for one patient with CCAM who was complicated by reexpansion lung edema requiring mechanical ventilation in the current series. Most of the cases with cystic lung disease, prognosis is good after lung resection. Rarely, in patients with bilateral lesions such as CCAM, outcome after bilateral resection of the lung was poor because of pulmonary hypoplasia [2,15]. The surgical resection of the involved lung results in good relief of symp-

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