CT and histopathological correlation of congenital cystic pulmonary lesions: a common pathogenesis?

[Congenital pulmonary malformations : Diagnosis and treatment]

PERFORMANCE

Congenital pulmonary malformations (CPM) are rare and can be associated with high morbidity. Clinical presentation, diagnostic procedures, imaging, and therapy of CPM are discussed.

ACHIEVEMENTS

Today, most CPM can be diagnosed prenatally by ultrasound. Postnatally, respiratory symptoms up to respiratory failure and recurrent lower respiratory tract infection are typical findings. Due to low diagnostic accuracy of chest x‑ray in CPM, all children with prenatal diagnosis of CPM or postnatally suspected CPM should undergo cross-sectional imaging.

PRACTICAL RECOMMENDATIONS

Based on imaging alone, the various subtypes of CPM cannot be definitively differentiated, which is why histological confirmation remains the gold standard. Surgical resection is the standard of care with minimally invasive procedures increasingly being employed. In certain situations, a watch-and-wait approach is possible.

Quantitative CT imaging analysis to predict pathology features in patients with a congenital pulmonary airway malformation

BACKGROUND

Risk for infection and potential malignant degeneration are the most common arguments for resecting asymptomatic Congenital Pulmonary Airway Malformations (CPAM). We aimed to investigate if CT- imaging characteristics can be used to predict histopathological features, by using an objective quantitative CT scoring method.

METHODS

Archival CPAM tissue samples were histologically re-assessed and patients who had a pre-operative volumetric CT-scan were included. Lung disease was quantified using the newly-developed congenital lung abnormality quantification(CLAQ) scoring method and obtained percentages were used to predict histopathological signs of inflammation and presence of mucinous proliferation (MP). Because MP is presumed a precursor for mucinous adenocarcinoma in situ (AIS) this method was also used to compare CT-scans of patients with AIS to those with only CPAM.

RESULTS

Thirty-three CPAM patients were included of which 13(39%) had histological signs of inflammation and 8(24%) had a MP. Patients with inflammation had a significantly smaller lesion (14% vs 38%) while those with MP had more extensive disease (54%vs17%). Patients with AIS had a significantly smaller lesion compared to CPAM patients (5%vs29%). Significant predictors for inflammation were smaller lesion size and percentage hypodensity within lesions while a larger lesion size and percentage parenchymal hyperdensity (solid lung tissue components) were predictors for MP as well as AIS.

CONCLUSIONS

Smaller CPAM lesions may be more susceptible to inflammation while larger lesions may be associated with the presence of MP. Parenchymal hyperdensity is found as a predictor for MP as well as AIS and should therefore elicit more extensive gross sampling.

LEVEL OF EVIDENCE

Level III.

A clinical guideline for structured assessment of CT-imaging in congenital lung abnormalities

OBJECTIVES

To develop a clinical guideline for structured assessment and uniform reporting of congenital lung abnormalities (CLA) on Computed Tomography (CT)-scans.

MATERIALS AND METHODS

A systematic literature search was conducted for articles describing CT-scan abnormalities of congenital pulmonary airway malformation (CPAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema (CLE) and bronchogenic cyst (BC). A structured report using objective features of CLA was developed after consensus between a pediatric pulmonologist, radiologist and surgeon.

RESULTS

Of 1581 articles identified, 158 remained after title-abstract screening by two independent reviewers. After assessing full-texts, we included 28 retrospective cohort-studies. Air-containing cysts and soft tissue masses are described in both CPAM and BPS while anomalous arterial blood supply is only found in BPS. Perilesional low-attenuation areas, atelectasis and mediastinal shift may be found in all aforementioned abnormalities and can also be seen in CLE as a cause of a hyperinflated lobe. We have developed a structured report, subdivided into five sections: Location & Extent, Airway, Lesion, Vascularization and Surrounding tissue.

CONCLUSIONS

CT-imaging findings in CLA are broad and nomenclature is variable. Overlap is seen between and within abnormalities, possibly due to definitions often being based on pathological findings, which is an unsuitable approach for CT imaging. We propose a structured assessment of CLA using objective radiological features and uniform nomenclature to improve reporting.

ACR Appropriateness Criteria® Pneumonia in the Immunocompetent Child

Pneumonia is one of the most common acute infections and the single greatest infectious cause of death in children worldwide. In uncomplicated, community-acquired pneumonia in immunocompetent patients, the diagnosis is clinical and imaging has no role. The first role of imaging is to identify complications associated with pneumonia such as pleural effusion, pulmonary abscess, and bronchopleural fistula. Radiographs are recommended for screening for these complications and ultrasound and CT are recommended for confirmation. The second role of imaging is to identify underlying anatomic conditions that may predispose patients to recurrent pneumonia. CT with intravenously administered contrast is recommended for this evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Congenital Cystic Lung Lesions: Redefining the Natural Distribution of Subtypes and Assessing the Risk of Malignancy

Asymptomatic cystic lung lesions-congenital pulmonary airway malformations (CPAMs), sequestrations, and bronchogenic cysts-are commonly diagnosed prenatally. Indications to resect are to eliminate risk of malignancy or infection. CPAMs consist of a spectrum of malformations, with type 1 historically considered the most common. Mucinous cell clusters, seen almost exclusively in type 1, are premalignant lesions at risk for progression to mucinous adenocarcinoma. We reviewed and classified 2.5 years of consecutive, prenatally diagnosed lesions as extralobar sequestration, intralobar sequestration, type 1 CPAM, type 2 CPAM/bronchial atresia, or "other" to determine the distribution of lesion types and risk of malignancy. One hundred eighty-four lesions in 174 patients showed type 1 CPAM to be least common subtype. Type 1 CPAMs had more severe presentation, infrequently had features of obstruction, and usually had cysts ≥2 cm. Fifteen of eighteen type 1 CPAMs had mucinous cell clusters (total risk, 8%), with mucous cells outside main cyst in 12/15. No pleuropulmonary blastomas were identified. Additional historic cases were reviewed to further evaluate risk of malignancy. Over 14 years, 28 infants with fetal/type 1 lesions were identified, with clusters of mucinous cells in 75% of cases. A total of 9 pleuropulmonary blastomas were diagnosed in 6 patients over 16 years. Contrary to historical studies, type 1 CPAMs are much less common than type 2, likely related to detection of asymptomatic lesions prenatally. A majority of type 1 CPAMs contain mucinous cell clusters. This data is useful in management of patients in centers that do not resect asymptomatic lesions.

Cystic and pseudocystic pulmonary malformations in children: Clinico-pathological correlation

Pulmonary malformations are rare disorders, with cystic and pseudocystic pulmonary malformations (CPPM) the most frequent, and constitute the first cause of lobectomy in children <1 year of age. Morphological overlap of congenital cystic pulmonary lesions might correspond to a spectrum of lesions in which bronchial atresia is a common etiopathogenetic mechanism. We aimed to report the frequency of CPPM resected in a tertiary-level hospital and to evaluate the degree of agreement between presurgical and anatomopathological diagnoses. We studied 44 surgical pieces with a diagnosis of CPPM received at the Pathology Service from 2009 to 2014, resected from 39 patients, 51.3 % males, with a median age of 16.8 months. Up to 69.2% of the patients had adenomatoid malformation of pulmonary airway (AMPA), with type 2 the most frequent (55.5%). Pulmonary sequestration was present in 15.4% of patients; in two cases the diagnosis was an incidental finding during surgery for the repair of a diaphragmatic hernia. Congenital lobar hyperinflation (CLH) occurred in 7.6% cases. Bronchogenic cyst (BC) was present in 7.6% cases. Presurgical and anatomopathological diagnoses in all patients coincided in 71.8% of cases. Kappa coefficient was 0.56 for global concordance in patients with AMPA, and 0.72, 0.64, 0.37 and 0.33 for CLH, BC, and types 1 and 2 AMPA, respectively. This relatively low interobserver agreement could reflect the low reproducibility of diagnoses used in the current nomenclature. Thus, the new nomenclature must be promoted in order to allow for better reproducibility and greater clinico-pathological concordance. The anatomopathological analysis must include the intentional search for bronchial atresia.

Prenatal and Postnatal Management of Congenital Pulmonary Airway Malformation

Congenital pulmonary airway malformation (CPAM) is one of the most common lung lesions detected prenatally. Despite the research efforts made in the past few years, controversy and lack of clarity in the literature still exist regarding nomenclature, classification, pathogenesis and the management of CPAM. Therefore, it is of greatest importance to delineate the natural history of CPAMs and to create a consensus to guide the management and follow-up of these lesions. This review will focus on classification systems, highlighting the most recent advancements in pathogenesis, and current practice in the prenatal diagnosis of CPAM. Strategies of prenatal management and postnatal management will be reviewed. Long-term follow-up, including lung cancer risk, is discussed and an outcome perspective is presented.

Rare Lung Diseases: Congenital Malformations

Increasingly, congenital thoracic malformations (CTMs) are diagnosed on antenatal ultrasound, but we lack the evidence to suggest rational management, not least because descriptive terms are used inconsistently. This review describes a simplified clinical classification of CTMs, and contrasts it with pathological descriptions. The age related presentations of CTM are described, together with the differential diagnoses of cystic masses presenting both antenatally and postnatally. Antenatally diagnosed CTMs rarely require intervention before birth; and urgent treatment is only required postnatally if the baby is symptomatic and does not respond to medical management. The asymptomatic baby with an antenatal diagnosis of a CTM presents a management conundrum. Definitive imaging is with high-resolution computed tomography (HRCT), but the optimal timing of imaging is unclear. Whether surgery should be offered to asymptomatic infants is also unclear; in the medium term, 5 % of asymptomatic babies will require surgery for complications of the disease. The most vexed question is malignant change; the risk in the medium term is probably less than 5 %, but we have no way of delineating a high-risk group. Indeed, malignancy has been described even after complete resection of a CTM. The author's personal management is to advocate surgery in the second year of life for all except for the most trivial CTMs, but many would differ and advocate conservative management. More data are needed if we are to rationalise our approach to these infants.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

Pre and perinatal aspects of congenital cystic adenomatoid malformation of the lung

OBJECTIVE

To identify the incidence of congenital cystic adenomatoid malformation of the lung (CCAM) at birth; to evaluate prenatal and perinatal history, association with clinical and sociodemographic variables and concordance between CT scan results and anatomopathology studies.

METHOD

Descriptive study based on the registry of malformed newborns, deliveries and patients records between August 1990 and November 2010. Ultrasonic, clinical, imaging and anatomopathologic information were studied. Association studies were made using chi-square test. Kappa was used to correlate CT scan to anatomopathology results.

RESULTS

The incidence was 1:1980 (25/49 503). The mean gestational age for detection by ultrasonography was 24 ± 3.7 weeks. There were progression of the lesions in 11 cases (44%), stability in 6 (24%) and regression in 8 (32%). Three cases of CCAM followed due to polyhydramnios/hydrops died. There were neither familial cases nor association with sex, weight, age or maternal parity (p > 0.15). Radiographic abnormalities were found in 22/23 studied patients. The correspondence between CT scan and anatomopathologic was 0.77 (Kappa).

CONCLUSIONS

The incidence was higher than the one described in the literature, probably, because it is a reference center in fetal medicine. The prenatal lesion involution rate was 32%, an intermediate proportion. There was good concordance between CT scan and anatomopathologic results. The polyhydramnios/hydrops were predictive of worst prognosis.

Comparison between US and MRI in the prenatal assessment of lung malformations

BACKGROUND

The contribution of MRI in the prenatal evaluation of congenital lung abnormalities (CLA) has not been extensively investigated.

OBJECTIVE

(1) To compare diagnostic accuracy and assessment of prognostic factors between US and MRI in CLA and (2) to assess the diagnosis agreement between prenatal imaging and postnatal diagnosis.

MATERIALS AND METHODS

We included 23 consecutive fetuses who underwent concomitant US and MRI during gestation as well as postnatal CT and surgery (n = 22).

RESULTS

US-MRI sets were performed at median gestational age of 26 (n = 16) and 34 (n = 22) weeks. Postnatal diagnoses were 11 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 6 hybrid lesions and 2 cysts. US and MRI agreement was significantly better during the second trimester than during the third one (P = 0.02). Disagreements were related to missed cysts (n = 5), mediastinal shift (n = 6) and vessels (n = 5). US and MRI diagnosis agreement was present in 20 cases, including 5 cases of misdiagnosis. US and MRI were concordant with postnatal diagnosis in 17 and 16 cases, respectively.

CONCLUSION

In our series, no clear superiority of MRI over US in the prenatal evaluation of CLA was demonstrated, but US better demonstrated systemic feeding vessels and MRI cysts and normal lung adjacent to the lesion.

Fetal bronchoscopy: its successful use in a case of extralobar pulmonary sequestration

OBJECTIVE

To report the performance of fetal bronchoscopy in a case of pulmonary sequestration.

MATERIALS AND METHODS

A 24 year-old female, Gravida 2, Para 1, was referred at 27.5 weeks with a large fetal left lung mass with marked right mediastinal shift and no visible normal left lung. Differential diagnosis included possible bronchial atresia.

RESULTS

The patient underwent fetal laryngoscopy and fetal bronchoscopy at 31.5 weeks. The right lung and a portion of the left lung expanded during surgery as a result of bronchial lavage. Bronchial atresia or bronchogenic cyst were not found. Pregnancy continued uneventfully, with continuous growth of the right lung and a small amount of left lung. The patient delivered vaginally at term. The baby underwent thoracoscopic resection of a pulmonary sequestration at 10.5 months of age and did well.

CONCLUSION

Fetal bronchoscopy is feasible. The procedure may prove useful in the differential diagnosis and in the potential treatment of different fetal lung lesions, as well as aid in the understanding of the role of bronchial obstruction as a common pathophysiologic mechanism for different fetal lung masses. Risks and benefits of fetal bronchoscopy warrant further experience.

Prediction of pediatric outcome after prenatal diagnosis and expectant antenatal management of congenital cystic adenomatoid malformation

OBJECTIVE

To determine whether the congenital cystic adenomatoid malformation (CCAM) volume ratio (CVR) is associated with fetal and postnatal outcome after prenatal diagnosis and antenatal expectant management in a provincial tertiary referral center that does not offer fetal surgery.

METHODS

Retrospective cohort of 71 consecutive cases of prenatally diagnosed CCAM meeting study criteria (1996-2004). CVR was calculated on the initial ultrasound at the referral center, and associated with hydrops (Fisher's exact test) and a composite adverse postnatal outcome consisting of death, intubation for respiratory distress, extracorporeal membrane oxygenation, non-elective surgery for symptomatology, or respiratory infection requiring hospital admission (Mann-Whitney test).

RESULTS

A CVR > 1.6 was significantly associated with hydrops (p = 0.003). In addition, the CVR was significantly associated with the composite adverse postnatal outcome (p = 0.004) at a mean age of follow-up of 41 months (range < 1-117 months). For CVR and postnatal outcome, the area-under-the-curve receiver operating characteristic was 0.81 (95% CI 0.69-0.93, p = 0.006), and choosing a CVR cut-off of < 0.56, the negative predictive value was 100% (95% CI 0.85-1.00).

CONCLUSION

In a provincial referral center with antenatal expectant management of CCAM, the CVR was associated with hydrops and postnatal outcome, with a CVR < 0.56 predictive of good prognosis after birth.

Congenital bronchial atresia: diagnosis and treatment

This study aimed to retrospectively summarize the clinical signs, diagnosis, and treatment of congenital bronchial atresia (CBA) in 12 patients. Chest radiographs and computed tomographic (CT) images of 12 patients with CBA treated in the Chinese People's Liberation Army General Hospital were reviewed. Analysis of chest radiographs revealed ten patients had hilar mass-like shadows and two had pneumonia-like shadows; most patients (n = 8) showed hyperlucency of the peripheral lung fields. CT revealed a mucocele in all the patients (n = 12); the mucoceles were round in four patients and club-like in eight. In 80% of the cases (n = 10), associated anomalies, including occlusions of the bronchus central to the mucocele, emphysematous changes of the peripheral lung fields, bronchogenic cyst, and anomalous branching of the bronchial tree and vascular structure were observed. CBA was detected in the right lobe in eight patients and the left lobe in the remaining four. No surgical intervention was performed in 5 CBA patients and the remaining 7 patients underwent surgery, including lobectomy in 5 patients and local resection in 2 patients. Among these 7 patients, 3 had a preoperative diagnosis of malignant disease, and the remaining 4 had severe clinical symptoms that could not be effectively treated by medicines. All patients were followed up, and none experienced obvious discomfort. CBA is a relatively rare and benign malformation disease. Chest CT is the procedure of choice for diagnosis. The presence of a bronchocele and surrounding emphysematous changes are typical radiologic findings in CBA. Surgery should be reserved only for patients with serious complications secondary to the atretic bronchus.

Pulmonary arteriovenous fistula within a pulmonary cyst - evaluation with CT pulmonary angiography

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct communications between pulmonary arteries and pulmonary veins. These abnormal communications result in an anatomical right-to-left shunt that reduces the arterial oxygen saturation and may cause hypoxaemia and dyspnoea. Although PAVMs frequently remain undiagnosed, they are associated with severe morbidity in the form of ischaemic strokes and brain abscesses. We report a case of incidental CT angiography depiction of a PAVM within a pulmonary cyst. To the best of our knowledge, no such case has been described previously. On the basis of its appearance and lack of typical clinical features of hereditary haemorrhagic telangiectasia (HHT), we suggest that this PAVM actually represents an acquired fistula from a previously unrecognised focal pulmonary insult, such as trauma or infection, that simultaneously evolved into a pulmonary arteriovenous fistula (PAVF) within a traumatic pulmonary cyst or pneumatocele.

Pulmonary congenital cystic disease in adults. Spiral computed tomography findings with pathologic correlation and management

PURPOSE

The aim of this study was to assess the computed tomography (CT) features of intrapulmonary congenital cystic diseases in adults and to correlate the imaging features with the pathological findings, with emphasis on the oncogenic potential of the lesions.

MATERIALS AND METHODS

We retrospectively reviewed the CT scans in three institutions from August 1996 to December 2008, of nine patients (six men, three women; mean age 48.6 years; range 26-75 years) who had histological diagnosis of pulmonary cystic disease after surgery. Six patients had a diagnosis of intrapulmonary bronchogenic cyst (IBC), and three had a type-I cystic adenomatoid malformation (CAM). In one case, intralobar sequestration (ILS) was associated with type-I CAM.

RESULTS

Three patients were symptomatic and six were asymptomatic. On CT scans, IBCs showed homogeneous fluid attenuation (n=2), air-fluid level (n=2), air attenuation (n=1) or soft-tissue attenuation (n=1). The surrounding lung tissue showed areas of band-like linear attenuation in three IBCs, atelectasia in two and mucocele-like areas in one. On CT, type-I CAM appeared as a unilocular cystic lesion with air-fluid level (n=1) or air content (n=1). Both cases had thin walls surrounded by normal lung parenchyma. ILS appeared as a fluid-filled cyst with afferent and efferent vessels. Of the six IBCs, one occurred in the upper right lobe, two in the middle lobe and three in the lower right lobe. Of the three type-I CAMs, one was in the upper left lobe and one in the middle lobe. The type-I CAM associated with ILS was located in the left lower lobe.

CONCLUSIONS

The similar CT patterns preclude differentiation between IBC and type-I CAM. Surgical resection of all intrapulmonary cystic lesions detected in adults is mandatory because type-I CAM is a precursor of mucinous bronchioloalveolar carcinoma.

Commonly encountered surgical problems in the fetus and neonate

Neonatal surgical care requires a current understanding of pre- and postnatal intervention for a myriad of congenital anomalies. This article includes an update of the recent information on commonly encountered fetal and neonatal surgical problems, highlighting specific areas of controversy and challenges in diagnosis. The authors hope that this article is useful for trainees and practitioners involved in any aspect of fetal and neonatal care.