Congenital Pulmonary Airway Malformation

Congenital Lung Anomalies in Adults

Congenital lung anomaly (CLA) refers to a rare group of malformations that are typically identified prenatally or in early childhood. However, a significant proportion of cases evade detection until adulthood and either are incidentally discovered or manifest with symptoms of recurrent respiratory infection or pulmonary hemorrhage. While most CLAs have characteristic imaging findings at CT and MRI, they remain a diagnostic challenge due to the infrequency with which they are encountered in adults. Radiologists frequently play a pivotal role in suggesting the diagnosis and guiding appropriate management strategies, and recognition of characteristic imaging patterns is crucial for accurate diagnosis. The authors examine the imaging appearances and clinical manifestations in adult patients with CLA, with a focus on patients who have bronchopulmonary involvement and those with combined bronchopulmonary and vascular anomalies. Entities discussed include bronchogenic cyst, bronchial atresia, congenital lobar overinflation, congenital pulmonary airway malformation, proximal interruption of the pulmonary artery, bronchopulmonary sequestration, hypogenetic lung syndrome, placental transmogrification of the lung, and hybrid lesions. Common complications that may arise in these patients are discussed and illustrated. ©RSNA, 2024 Supplemental material is available for this article.

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.

18FDG PET-Positive Congenital Pulmonary Airway Malformation Mimicking Lung Cancer

ABSTRACT

Adult cases of type 2 congenital pulmonary airway malformation (CPAM) are extremely rare, and no PET/CT findings have been reported for CPAM. We encountered a case of 18FDG PET-positive CPAM mimicking lung cancer in a 45-year-old asymptomatic man. CT revealed a large cavitary mass in the left lower lobe. SUVmax measured by 18FDG PET was 3.5. The patient underwent video-assisted thoracoscopic lobectomy on suspicion of CPAM with/or lung cancer. Histologically, no neoplastic cells were present, and the lesion was consistent with type 2 CPAM. An adenomatoid proliferative pattern and granulomatous lesions may have contributed to a PET/CT false-positive result.

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.

Invasive mucinous adenocarcinoma of the lung arising in a type 1 congenital pulmonary airway malformation in a 68-year-old patient: a case report

INTRODUCTION

Congenital pulmonary airway malformation (CPAM), previously described as congenital cystic adenomatoid malformation (CCAM), is a congenital disorder of lung parenchyma. The association with the presence of a malignant transformation like rhabdomyosarcoma, pleuropulmonary blastoma, and most common invasive mucinous adenocarcinoma (IMA) is a rare development described in patients with CPAM.

PATIENTS AND METHODS

Here, we report the case of a 68-year-old male patient who underwent a right lower lobectomy for a mass in the right pulmonary lobe. From his clinical history, we noted a recurrent pulmonary infection of a bullous malformation in the right lower lobe treated with antibiotics.

RESULTS

The histopathological finding showed an invasive mucinous adenocarcinoma arising in a type 1 CPAM in the right lower lobe. A review of presentation, diagnosis, and treatment of this association is described in a case report.

CONCLUSIONS

Surgical resection should be considered in adults with asymptomatic cysts to prevent malignant transformation. For further analysis, histopathological examination of specimen is essential for a proper diagnosis and eventually further postoperative treatment.

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 Pulmonary Airway Malformation in an Adult Male: A Case Report with Literature Review

Congenital pulmonary airway malformation (CPAM) is a rare cystic lung lesion formed as a result of anomalous development of airways in fetal life. Majority of the cases are recognized in neonates and infants with respiratory distress with very few presenting later in adult life. A 24-year-old male with history of three separate episodes of pneumonia in the last 6 months presented with left sided pleuritic chest pain for 4 days. He was tachycardic and tachypneic at presentation. White blood count was 14 × 10(9)/L. Chest X-ray showed left lower lobe opacity. CT angiogram of thorax showed a well-defined area of low attenuation in the left lower lobe with dedicated pulmonary arterial and venous drainage and resolving infection, suggesting CPAM. He underwent left lower lobe lobectomy. Histopathology confirmed type 2 CPAM. CPAM is a rare congenital anatomic abnormality that can present with recurrent infections in adults. As a number of cases remain asymptomatic and symptomatic cases are often missed, prevalence of CPAM might be higher than currently reported.