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A 38-Year-Old Woman With Bilateral Cystic Lesions in Both Lower Lung Lobes

2011; Elsevier BV; Volume: 140; Issue: 2 Linguagem: Inglês

10.1378/chest.10-1932

1931-3543

So Ri Kim, Min Hee Lee, Kyung Ae Lee, Seoung Ju Park, Kyung Hoon Min, Hyo Jin Han, Chi Ryang Chung, Kyoung Hwa Choi, Heung Bum Lee, Gong Yong Jin, Yong Chul Lee,

Head and Neck Anomalies

A 38-year-old woman visited our clinic because of intermittent nonproductive cough for several months. Her past medical history revealed no specific illness. She was a nonsmoker. On physical examination, her breath sounds were decreased on both lower lung fields. Laboratory tests revealed a leukocyte count of 8,540/μL with 74.2% neutrophils, erythrocyte sedimentation of rate 66 mm/h, and high sensitivity C-reactive protein level of 26.47 mg/L, and were otherwise normal. After reviewing the chest imaging, several diagnostic approaches were performed to define the possible causes for the cystic mass lesions, such as infections, malignancy, immunologic diseases, and embolism. There was no definitive endobronchial lesion on bronchoscopic examination, and bronchial washing was negative for malignancy. BAL cultures were negative for bacteria, Mycobacterium, virus, and fungi. Clinical assessment of the progress and response of the cystic lesions to the antibiotics revealed that there were no definitive infectious, immunologic, or malignant causes. We decided to remove the cystic lesions via surgical resection because there was no response to medical treatment, and the tissues were analyzed for diagnosis. After she received the final diagnosis pathologically, at 2-month follow-up, she had no complaints, and no evidence of the disease was found. Radiographic examinations with chest radiograph showed multicystic masses on the posterior basal segments of both lower lobes in which multiple air-fluid levels were observed (Fig 1). In addition, chest CT scan revealed two cystic lesions located on both lower lobes, about 8 cm ×4 cm in size. They were composed of multiple lobules and fluid collections, and the walls of cysts and lobules were thin and relatively smooth margined, showing soft tissue intensity without contrast enhancement. Interestingly, the cystic lesions on each lobe communicated with each other by a kind of canal, which was located between the heart and descending thoracic aorta (Fig 2). In addition, contrast-enhanced CT scan showed the absence of aberrant vessels leading to the cystic lesions.Figure 2Chest CT scan shows multicystic masses located in posterobasal segments of both lower lobes. A, Mediastinal window setting. B, Lung window setting. Walls of cysts and lobules are thin and relatively smooth margined, showing soft tissue intensity without contrast enhancement. The cystic lesions on each lobe are communicating through a bridge, which is located between the heart and descending thoracic aorta (arrow).View Large Image Figure ViewerDownload Hi-res image Download (PPT) The patient underwent left lower lobe lobectomy for the multicystic lesion. Grossly, the polycystic mass was on basal segments of the left lower lobe excised surgically. The mass size was 8.2 cm × 3.6 cm, and the cystic mass was relatively easily dissected from surrounding tissues. The color of the inner cyst wall was gray with multiple lobules, which were filled with pus-like material. Microscopically, numerous small cysts were separated by fibrous connective tissue, and the cystic wall was lined with pseudostratified ciliated and mucinous columnar epithelium (Fig 3). About 3 months later, she underwent right lower lobe lobectomy for the remnant cystic lesions. The pathologic findings for this 8.5 cm × 5 cm cyst from the right lower lobe were similar to those in the left lung. Using the radiologic images and the gross photograph of each specimen, we could identify the portion of the suspicious structure for the communication between two lesions. The communication was a tubular structure surrounded by walls composed of fibrous connective tissues. What is the diagnosis? Diagnosis: Bilateral congenital cystic adenomatoid malformation, type 1 Congenital cystic adenomatoid malformation (CCAM) is a rare pulmonary developmental disorder with replacement of normal pulmonary tissues by dilated bronchiolar-like airspaces having variable size and distribution.1Luján M Bosque M Mirapeix RM Marco MT Asensio O Domingo C Late-onset congenital cystic adenomatoid malformation of the lung. Embryology, clinical symptomatology, diagnostic procedures, therapeutic approach and clinical follow-up.Respiration. 2002; 69: 148-154Crossref PubMed Scopus (80) Google Scholar According to one report, the incidence of CCAM is approximately 1.2 per 10,000 births.2Duncombe GJ Dickinson JE Kikiros CS Prenatal diagnosis and management of congenital cystic adenomatoid malformation of the lung.Am J Obstet Gynecol. 2002; 187: 950-954Abstract Full Text Full Text PDF PubMed Scopus (99) Google Scholar It occurs sporadically, and there is no genetic predisposition or gender predilection.3Nishibayashi SW Andrassy RJ Woolley MM Congenital cystic adenomatoid malformation: 1 30-year experience.J Pediatr Surg. 1981; 16: 704-706Abstract Full Text PDF PubMed Scopus (48) Google Scholar The pathogenesis of CCAM remains unknown, although it is known as a failure of normal lung development.1Luján M Bosque M Mirapeix RM Marco MT Asensio O Domingo C Late-onset congenital cystic adenomatoid malformation of the lung. Embryology, clinical symptomatology, diagnostic procedures, therapeutic approach and clinical follow-up.Respiration. 2002; 69: 148-154Crossref PubMed Scopus (80) Google Scholar, 4Cha I Adzick NS Harrison MR Finkbeiner WE Fetal congenital cystic adenomatoid malformations of the lung: a clinicopathologic study of eleven cases.Am J Surg Pathol. 1997; 21: 537-544Crossref PubMed Scopus (55) Google Scholar, 5Alescio T Cassini A Induction in vitro of tracheal buds by pulmonary mesenchyme grafted on tracheal epithelium.J Exp Zool. 1962; 150: 83-94Crossref PubMed Scopus (179) Google Scholar Normal mammalian lung development begins as an outpouching of the developing foregut during the third week of embryogenesis. The outpouching proceeds to form two bronchial buds that penetrate into the associated splanchnic mesoderm at 4 weeks' gestation. Lung development is divided into several stages: pseudoglandular (embryonic period to 17th week), canalicular (17th to 24th week), terminal sac (24th week to term), and alveolar (postnatal life). Stocker classification type 3 resembles the pseudoglandular period of lung development, type 2 the canalicular period, and type 1 cannot be cataloged as one specific stage as it may arise from the pseudoglandular or canalicular period.4Cha I Adzick NS Harrison MR Finkbeiner WE Fetal congenital cystic adenomatoid malformations of the lung: a clinicopathologic study of eleven cases.Am J Surg Pathol. 1997; 21: 537-544Crossref PubMed Scopus (55) Google Scholar It has been reported that CCAM results from a failure of interaction between endoderm and mesoderm6Cardoso WV Itoh A Nogawa H Mason I Brody JS FGF-1 and FGF-7 induce distinct patterns of growth and differentiation in embryonic lung epithelium.Dev Dyn. 1997; 208: 398-405Crossref PubMed Scopus (172) Google Scholar or an imbalance between an increased cell proliferation and a decreased apoptosis within the developing lung.7Cass DL Quinn TM Yang EY Increased cell proliferation and decreased apoptosis characterize congenital cystic adenomatoid malformation of the lung.J Pediatr Surg. 1998; 33: 1043-1046Abstract Full Text PDF PubMed Scopus (134) Google Scholar In addition, CCAM is produced by a developmental failure due to a hypovascular development,8Cloutier MM Schaeffer DA Hight D Congenital cystic adenomatoid malformation.Chest. 1993; 103: 761-764Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar as seen in other malformations.9Mas A Mirapeix RM Domingo C Sañudo JR Torremorell MD Marín A Pulmonary hypoplasia presented in adulthood as a chronic respiratory failure: report of two cases. Embryology, clinical symptoms and diagnostic procedures.Respiration. 1997; 64: 240-243Crossref PubMed Scopus (9) Google Scholar CCAM is most commonly found in the neonatal period, and up to 90% of the cases are diagnosed within the first 2 years of life.10Morelli L Piscioli I Licci S Donato S Catalucci A Del Nonno F Pulmonary congenital cystic adenomatoid malformation, type I, presenting as a single cyst of the middle lobe in an adult: case report.Diagn Pathol. 2007; 2: 17Crossref PubMed Scopus (17) Google Scholar With advances in high-resolution diagnostic imaging techniques used for gestational follow-up, late-onset CCAM undoubtedly becomes rarer, and its detection requires a higher level of suspicion for its diagnosis.11Oh BJ Lee JS Kim JS Lim CM Koh Y Congenital cystic adenomatoid malformation of the lung in adults: clinical and CT evaluation of seven patients.Respirology. 2006; 11: 496-501Crossref PubMed Scopus (33) Google Scholar Clinical features of CCAM are variable, from asymptomatic to pulmonary complications. It usually presents in infancy with respiratory distress secondary to a space-occupying lesion that compromises normal lung tissues. Recurrent respiratory tract infection is the most common complication of adult CCAM presentation.12Shanmugam G Adult congenital lung disease.Eur J Cardiothorac Surg. 2005; 28: 483-489Crossref PubMed Scopus (30) Google Scholar In addition, adult presentation includes shortness of breath, lung abscess, spontaneous pneumothorax, pyopneumothorax, hemoptysis, cerebral air embolus during a long flight, and gastrointestinal bleeding with entire lung involvement.11Oh BJ Lee JS Kim JS Lim CM Koh Y Congenital cystic adenomatoid malformation of the lung in adults: clinical and CT evaluation of seven patients.Respirology. 2006; 11: 496-501Crossref PubMed Scopus (33) Google Scholar, 13Dahabreh J Zisis C Vassiliou M Arnogiannaki N Congenital cystic adenomatoid malformation in an adult presenting as lung abscess.Eur J Cardiothorac Surg. 2000; 18: 720-723Crossref PubMed Scopus (24) Google Scholar, 14Belcher E Lawson MH Nicholson AG Davison A Goldstraw P Congenital cystic adenomatoid malformation presenting as in-flight systemic air embolisation.Eur Respir J. 2007; 30: 801-804Crossref PubMed Scopus (27) Google Scholar Of all complications associated with CCAM, neoplastic transformation is the one with the worst prognosis and is usually found in older children or young adults. The incidence of CCAM-associated bronchioloalveolar carcinomas is 4 mm, the differential diagnosis should include various etiologies: neoplastic origin (bronchogenic carcinoma, metastases, lymphoma), infections by bacteria (Staphylococcus aureus, gram-negative bacteria, Mycobacterium, actinomycosis, and nocardiosis), fungi (aspergillosis, mucormycosis, and cryptococcosis) and/or parasites, immunologic diseases (Wegener granulomatosis), pulmonary embolism, pneumoconiosis, localized bronchiectasis, CCAM, and pulmonary sequestration.17Ryu JH Swensen SJ Cystic and cavitary lung diseases: focal and diffuse.Mayo Clin Proc. 2003; 78: 744-752Abstract Full Text Full Text PDF PubMed Scopus (147) Google Scholar The multicystic lesion with thick walls and solid content observed in our present case is more often seen in pulmonary sequestration, in infectious causes, and in necrotic cancer. In fact, it can be easy for CCAM to be confused with lung infections on radiographic examination. Moreover, small CCAM lesions may not be visible on chest radiographs.1Luján M Bosque M Mirapeix RM Marco MT Asensio O Domingo C Late-onset congenital cystic adenomatoid malformation of the lung. Embryology, clinical symptomatology, diagnostic procedures, therapeutic approach and clinical follow-up.Respiration. 2002; 69: 148-154Crossref PubMed Scopus (80) Google Scholar Therefore, using more advanced modalities, differential diagnosis has to be done from other rare cystic tumors, and the effort to find the small lesions is required.13Dahabreh J Zisis C Vassiliou M Arnogiannaki N Congenital cystic adenomatoid malformation in an adult presenting as lung abscess.Eur J Cardiothorac Surg. 2000; 18: 720-723Crossref PubMed Scopus (24) Google Scholar Specifically, in light of an association with pulmonary sequestration, the contrast-enhanced CT scan or CT scan angiogram is noteworthy for the distinction between CCAM and sequestration, since the absence of aberrant vessels to the cystic lesion is a key feature of CCAM. In all the series reported, CCAM occurs with equal frequency in the right and left lung, usually confined to one lobe, and there is a predilection for occurrence in the posterior basal segments of the lower lobes.12Shanmugam G Adult congenital lung disease.Eur J Cardiothorac Surg. 2005; 28: 483-489Crossref PubMed Scopus (30) Google Scholar The cases of multilobular disease are much less frequent, and thus the cases of bilateral diseases are rarer.1Luján M Bosque M Mirapeix RM Marco MT Asensio O Domingo C Late-onset congenital cystic adenomatoid malformation of the lung. Embryology, clinical symptomatology, diagnostic procedures, therapeutic approach and clinical follow-up.Respiration. 2002; 69: 148-154Crossref PubMed Scopus (80) Google Scholar Interestingly, our current patient had CCAM in both lobes, the posterior basal segments of the lower lobes, with a communicating bridge. It did not communicate any tracheobronchial tree or pleural space. The radiologic feature of the bridge between the two cystic lesions was similar to fibrotic septum in the lesions themselves. Supporting this radiologic finding, histologic examination showed that the bridge was composed of fibrotic connective tissues. Therefore, we hypothesized that this communicating bridge may be formed as the result of repetitive inflammation in the cystic lesions. In histopathologic examinations, CCAM lesions consist of cysts and solid airless tissues, usually with no cartilage in the wall. They may partially or entirely affect the pulmonary lobes.10Morelli L Piscioli I Licci S Donato S Catalucci A Del Nonno F Pulmonary congenital cystic adenomatoid malformation, type I, presenting as a single cyst of the middle lobe in an adult: case report.Diagn Pathol. 2007; 2: 17Crossref PubMed Scopus (17) Google Scholar CCAM can be readily distinguished from other intrapulmonary cysts and postinfectious pulmonary abscesses by the multiplicity of cysts of various sizes, by the presence of smooth muscle and absence of scar, and by the presence of respiratory lining cells and mucin-secreting cells.10Morelli L Piscioli I Licci S Donato S Catalucci A Del Nonno F Pulmonary congenital cystic adenomatoid malformation, type I, presenting as a single cyst of the middle lobe in an adult: case report.Diagn Pathol. 2007; 2: 17Crossref PubMed Scopus (17) Google Scholar On the basis of clinical, gross, and histopathologic criteria, Stocker et al18Stocker JT Madewell JE Drake RM Congenital cystic adenomatoid malformation of the lung. Classification and morphologic spectrum.Hum Pathol. 1977; 8: 155-171Abstract Full Text PDF PubMed Scopus (843) Google Scholar have classified CCAM into three types: type 1 is the most common type of CCAM (about 60% of cases) and is rarely associated with anomalies. This type is curable with surgical resection. Pathologic features of type 1 CCAM are single or multiple cysts with a maximum diameter of 10 cm with ciliated pseudostratified tall columnar epithelia, high content of smooth muscle cells, and elastic tissues. In some cases, cartilage is present in the wall of the cyst. Most adult patients with CCAM have Stocker type 1 features on histopathology, presumably because the severe forms are either stillborn or are operated during childhood. Type 2, accounting for 20% to 30% of cases, contains numerous smaller cysts, usually <1 cm in diameter, resembling ecstatic terminal bronchioles. Large alveolar-like structures are present among the cysts. In 50% of the cases, type 2 CCAM has been found to be associated with extralobar pulmonary sequestration19Laberge JM Flageole H Pugash D Outcome of the prenatally diagnosed congenital cystic adenomatoid lung malformation: a Canadian experience.Fetal Diagn Ther. 2001; 16: 178-186Crossref PubMed Scopus (320) Google Scholar and carries a worse prognosis because of the association of this type with other congenital anomalies.20Mendeloff EN Sequestrations, congenital cystic adenomatoid malformations, and congenital lobar emphysema.Semin Thorac Cardiovasc Surg. 2004; 16: 209-214Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar Type 3, accounting for 10%, forms a solid and bulky mass, composed of regularly spaced bronchiole-like structures separated by masses of alveolus-like structures lined by cuboidal epithelium. In the modified classification in 2002, according to their resemblance to normal anatomic structures from proximal to distal, types 0 and 4 were added.21Stocker JT Congenital pulmonary airway malformation: a new name for and an expanded classification of congenital cystic adenomatoid malformation of the lung.Histopathology. 2002; 41: 424-431Google Scholar A type 0 lesion involves all five lobes and is incompatible with life. Type 4 CCAM is rare overall, accounting for <15% of all CCAMs. This type is peripheral, typically solitary lesions, comprising thin-walled cystic spaces lined predominantly by pneumocytes with the intervening stroma being generally of low cellularity and showing no cytologic atypia, in which lesions are histologically similar to cystic pleuropulmonary blastoma. In fact, in a large percentage of cases of type 4 CCAM, cystic pleuropulmonary blastomas have been identified; thus, type 4 CCAM lesions should be considered malignant. In this report, we describe a rare case of CCAM detected in adulthood, which showed bilateral presentation having a communicating bridge between each contralateral lobar lesion without any chronic or respiratory complications, with reviewing the clinical, radiologic, and pathologic features of CCAM. Histopathologically, it was defined as a CCAM type 1 as judged by the modified Stocker classification. Although the incidence is low, chest physicians should be aware that CCAM can be detected in adulthood without any chronic or recurrent respiratory complications and that it can show bilateral presentation, which in some cases can even communicate with each other. In addition, we recommend using more advanced modalities, such as chest CT scan, for differential diagnosis from other cystic diseases, because CCAM can be confused with lung infections, such as an abscess, on radiographic examination.