Pleuropulmonary Blastoma in Pediatric Lung Lesions

Abstract

BACKGROUND: Pediatric lung lesions are a group of mostly benign pulmonary anomalies with a broad spectrum of clinical disease and histopathology. Our objective was to evaluate the characteristics of children undergoing resection of a primary lung lesion and to identify preoperative risk factors for malignancy. METHODS: A retrospective cohort study was conducted by using an operative database of 521 primary lung lesions managed at 11 children’s hospitals in the United States. Multivariable logistic regression was used to examine the relationship between preoperative characteristics and risk of malignancy, including pleuropulmonary blastoma (PPB). RESULTS: None of the 344 prenatally diagnosed lesions had malignant pathology (P < .0001). Among 177 children without a history of prenatal detection, 15 (8.7%) were classified as having a malignant tumor (type 1 PPB, n = 11; other PPB, n = 3; adenocarcinoma, n = 1) at a median age of 20.7 months (interquartile range, 7.9–58.1). Malignancy was associated with the DICER1 mutation in 8 (57%) PPB cases. No malignant lesion had a systemic feeding vessel (P = .0427). The sensitivity of preoperative chest computed tomography (CT) for detecting malignant pathology was 33.3% (95% confidence interval [CI]: 15.2–58.3). Multivariable logistic regression revealed that increased suspicion of malignancy by CT and bilateral disease were significant predictors of malignant pathology (odds ratios of 42.15 [95% CI, 7.43–340.3; P < .0001] and 42.03 [95% CI, 3.51–995.6; P = .0041], respectively). CONCLUSIONS: In pediatric lung masses initially diagnosed after birth, the risk of PPB approached 10%. These results strongly caution against routine nonoperative management in this patient population. DICER1 testing may be helpful given the poor sensitivity of CT for identifying malignant pathology.

Accuracy of Chest Computed Tomography in Distinguishing Cystic Pleuropulmonary Blastoma From Benign Congenital Lung Malformations in Children

“…Study radiologists increased the sensitivity for detecting a malignant primary lesion to 58% but had reduced specificity (83%) when compared with the original CT interpretation (eTable 2 in Supplement 1 ). Based on the estimated disease prevalence of PPB among postnatally diagnosed lung lesions, 16 the calculated PPV was 24% and the NPV was 95%. The sensitivity of the study radiologists for detecting a CPAM was 56% and the specificity was 70%.…”

“… 21 , 38 , 39 Less than 5% of PPBs are detected prenatally. 18 , 20 , 40 , 41 The only radiologic feature that is thought to be pathognomic for benign disease is the presence of a systemic feeding vessel, 16 , 18 and our study radiologists correctly excluded malignancy in their review of all confirmed BPS lesions. The significance of other image-based characteristics in identifying PPB is more controversial.…”

“…We excluded prenatally diagnosed lesions given the known association of PPB with an initial diagnosis in the postnatal period. 6 , 16 , 20 , 29 , 30 Computed tomography scans from pathologically confirmed cystic PPBs (cases) were then individually age-matched with CT scans from pathologically confirmed benign CLMs (controls) at a target ratio of 1:3. We deliberately enriched for macrocystic CPAMs when possible and selected against BPS and CPAM with systemic feeding vessels, given the known association between systemic feeding vessels and benign disease.…”

“…Positive predictive values (PPVs) and negative predictive values (NPVs) were calculated based on PPB prevalence estimates as described elsewhere. 16 , 23 Interrater reliability was assessed using the Cohen κ statistic and intraclass correlation coefficient with 2-way mixed-effects modeling. The following levels of interrater agreement were used for interpretation: lower than 0.50 = poor, 0.50 to 0.74 = moderate, 0.75 to 0.90 = good, and higher than 0.90 = excellent.…”

Unusual thoracic tumor in a teenager: A rare occurrence

“…However, many patients with PPB were found to have a negative family history for PPB-associated cancer. 13 Therefore, screening for DICER1 carriers among her siblings or first-degree relatives may be beneficial, as it can potentially lead to the earlier detection of related cancers or type 1 PBB before progression to types 2 and 3.…”