Pleuropulmonary blastoma: a single-institution experience

Patient Characteristics, Treatment, and Survival in Pleuropulmonary Blastoma: An Analysis from the National Cancer Database

Pleuropulmonary blastoma (PPB) is a rare childhood tumor originating from the lung or pleura, typically treated with surgery, chemotherapy (CTx), and/or radiation therapy (RTx). This study aimed to assess patient and tumor features, treatment methods, and survival rates in PPB. We retrospectively analyzed PPB patients under 18 from 2004 to 2019, using the National Cancer Database (NCDB). We assessed 5-year overall survival (OS) rates based on disease presentation and treatment regimens, using Kaplan-Meier curves and Cox proportional regression. Among 144 cases identified, 45.9% were female, with a median age of 2 years (interquartile range 1-3). In all, 62.5% of tumors originated from the lung, and 10.4% from the pleura. Moreover, 6.9% were bilateral, and the median tumor size was 8.9 cm, with 4.2% presenting with metastases. The 5-year OS rate was 79.6%, with no significant change over time (2004-2009, 77.6%; 2010-2014, 90.8%; 2015-2019, OS 75.3%; p = 0.08). In all, 5.6% received CTx alone, 31.3% surgery alone, 45.8% surgery/CTx, and 17.4% surgery/CTx/RTx. The OS rates were comparable between the surgery/CTx/RTx (80.0%) and surgery/CTx (76.5%) groups (adjusted Hazard Ratio, 1.72; 95% CI, 0.57-5.19; p = 0.34). Therefore, due to the unchanged survival rates over time, further prospective multicenter studies are needed to determine the optimal multimodal treatment regimens for this rare pediatric tumor.

Outcomes for Children With Type II and Type III Pleuropulmonary Blastoma Following Chemotherapy: A Report From the International PPB/DICER1 Registry

PURPOSE

Pleuropulmonary blastoma (PPB) is the most common primary lung neoplasm of infancy and early childhood. Type II and type III PPB have historically been associated with a poor prognosis.

METHODS

Patients with known or suspected PPB were enrolled in the International PPB/DICER1 Registry. Medical records were abstracted with follow-up ascertained annually. All PPB diagnoses were confirmed by central pathology review. Beginning in 2007, the IVADo regimen (ifosfamide, vincristine, actinomycin-D, and doxorubicin) was recommended as a potential treatment regimen for children with type II and type III PPB. This regimen was compared with a historical control cohort.

RESULTS

From 1987 to 2021, 314 children with centrally confirmed type II and type III PPB who received upfront chemotherapy were enrolled; 132 children (75 with type II and 57 with type III) received IVADo chemotherapy. Adjusted analyses suggest improved overall survival for children treated with IVADo in comparison with historical controls with an estimated hazard ratio of 0.65 (95% CI, 0.39 to 1.08). Compared with localized disease, distant metastasis at diagnosis was associated with worse PPB event-free survival and overall survival with hazard ratio of 4.23 (95% CI, 2.42 to 7.38) and 4.69 (95% CI, 2.50 to 8.80), respectively.

CONCLUSION

The use of IVADo in children with type II and type III PPB resulted in similar-to-improved outcomes compared with historical controls. Inferior outcomes with metastatic disease suggest the need for novel therapies. This large cohort of uniformly treated children with advanced PPB serves as a benchmark for future multicenter therapeutic studies for this rare pediatric tumor.

Treatment and prognosis of pleuropulmonary blastoma: A single-center report of 31 cases

OBJECTIVES

Pleuropulmonary blastoma (PPB) is a very rare and highly aggressive neoplasm occurring in children, mostly under 6 years of age. We assessed the clinical characteristics, treatment modalities, treatment outcomes, and prognostic factors affecting survival in patients with PPB treated at our institution over a 10-year period to improve the prognosis.

METHODS

From November 2008 to November 2019, 31 children (21 boys and 10 girls) with a median age of 30 months (ranging, 22 days to 54 months) were treated at our institution. Here we describe the patient characteristics, treatment modalities, and treatment outcomes. The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS). Log-rank test was performed for comparison between groups.

RESULTS

Three children were lost to follow-up and two were dead due to postoperative complications. Of the 26 patients included in the follow-up, 16 PPB patients displayed tumor-free survival. The 5-year PFS and OS were 60.4% and 60.1% respectively. By stratified statistical analysis, the 5-year PFS and OS of type I PPB were 100%, while those of type III PPB were 43.7% and 43%, respectively. The 5-year PFS and OS of complete tumor resection were 76.5% and 75.6%, respectively, while those with tumor residue were 31.3%. The 5-year PFS and OS combined with chemotherapy were 62.2% and 61.6%, respectively, while those without chemotherapy were 0%.

CONCLUSIONS

PPB is an aggressive neoplasm. The main factors related to the prognosis of PPB are pathological type, tumor resection degree, and postoperative adjuvant therapy.

The Effect of Gross Total Resection on Patients with Pleuropulmonary Blastoma

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common primary lung cancer in children. While rare, these tumors are highly aggressive. Tumor recurrence and overall survival are dependent on histologic grade and extent of surgical resection. We sought to examine our institutional experience with PPB to determine the effect of gross total resection (GTR) on recurrence and patient outcomes.

MATERIALS AND METHODS

After IRB approval, a retrospective chart review from 1998 to 2018 was performed. Cases were confirmed by histology and Dehner Grade (I to III). Data collection included demographics, treatment, extent of surgical resection, and patient outcomes.

RESULTS

Eight patients with nine procedures were identified. Histologically, three cases were type 1, 2 type 2, and four poor prognosis type 3. Three patients received neoadjuvant chemotherapy to facilitate surgical resection. The operative goal was to achieve GTR (>95%), and to this end, three partial lobectomies, five lobectomies, and one pneumonectomy were performed. All nine cases achieved GTR, of which eight had negative microscopic margins. Two patients with type III disease recurred (one locally, one distant) and died. One type 3 patient had a positive microscopic hilar margin not amenable to further resection. The patient recurred (distant) but is in remission. With respect to patient outcomes, the event-free survival was 2.3 y with an overall survival of 3.3 y.

CONCLUSIONS

From our experience, GTR of PPB is associated with minimal surgical morbidity and good overall survival. Multi-institutional studies are needed to determine if positive surgical margins affect outcomes given the morbidity of mediastinal dissection.

Insulin-like Growth Factor 2 Gene Expression Molecularly Differentiates Pleuropulmonary Blastoma and Embryonal Rhabdomyosarcoma

The sarcomatous element in pleuropulmonary blastoma (PPB) is often histologically indistinguishable from embryonal rhabdomyosarcoma (ERMS). A diagnosis of PPB is often made after definitive surgical resection based on pathologic features, most notably the presence of hamartomatous pulmonary elements. Samples from seven PPB patients were obtained from the rhabdomyosarcomatous portion of the tumor by macrodissection. Representative ERMS tumor tissue was selected from 21 ERMS patient samples. Formalin-fixed paraffin-embedded tissue scrolls from each sample were analyzed using the Affymetrix Human Exon arrays. All PPB patients and 7 of 21 ERMS patients were 3 years old and younger. Twenty transcripts (10 annotated, 10 noncoding RNAs) were significantly differentially expressed in ERMS when compared with PPB samples. Insulin-like growth factor 2 (IGF2) was uniformly overexpressed in ERMS (19/21>400) but was expressed at low levels in PPB (P<0.001). Two ERMS cases that had low level IGF2 expression were 3 years and younger of age. No other differences between the 2 approached this degree of significance, despite a common rhabdomyogenic phenotype in the sarcomatous areas of PPB. PPB, unlike most ERMS, appears not to be driven by autocrine IGF2 signaling.

Pleuropulmonary blastoma: a report on 350 central pathology-confirmed pleuropulmonary blastoma cases by the International Pleuropulmonary Blastoma Registry

BACKGROUND

Pleuropulmonary blastoma (PPB) has 3 subtypes on a tumor progression pathway ranging from type I (cystic) to type II (cystic/solid) and type III (completely solid). A germline mutation in DICER1 is the genetic cause in the majority of PPB cases.

METHODS

Patients confirmed to have PPB by central pathology review were included, and their clinical characteristics and outcomes were reported. Germline DICER1 mutations were sought with Sanger sequencing.

RESULTS

There were 435 cases, and a central review confirmed 350 cases to be PPB; 85 cases (20%) were another entity. Thirty-three percent of the 350 PPB cases were type I or type I regressed (type Ir), 35% were type II, and 32% were type III or type II/III. The median ages at diagnosis for type I, type II, and type III patients were 8, 35, and 41 months, respectively. The 5-year overall survival (OS) rate for type I/Ir patients was 91%; all deaths in this group were due to progression to type II or III. OS was significantly better for type II versus type III (P = .0061); the 5-year OS rates were 71% and 53%, respectively. Disease-free survival (DFS) was also significantly better for type II versus type III (P = .0002); the 5-year DFS rates were 59% and 37%, respectively. The PPB type was the strongest predictor of outcome. Metastatic disease at the diagnosis of types II and III was also an independent unfavorable prognostic factor. Sixty-six percent of the 97 patients tested had a heterozygous germline DICER1 mutation. In this subset, the DICER1 germline mutation status was not related to the outcome.

CONCLUSIONS

Cystic type I/Ir PPB has a better prognosis than type II, and type II has a better outcome than type III. Surveillance of DICER1 carriers may allow the earlier detection of cystic PPB before its progression to type II or III PPB and thereby improve outcomes.

[Case report of pulmonary biphasic tumor with unusual follow-up]

BACKGROUND

Pulmonary blastoma, a rare primary lung malignancy is subdivided in 3 categories: well-differentiated fetal adenocarcinoma (WDFA), classic biphasic pulmonary blastoma (CBPB) and pleuropulmonary blastoma (PPB). Classic pulmonary blastoma is composed of a mixture of immature epithelial and mesenchymal tissue resembling fetal lung tissue.

CASE REPORT

We described a case of a 48-year-old male, cigarette smoker, who presented with left thoracic pain and hemoptysis for 2 months. Chest radiography showed a well-delimited, homogeneous 4cm mass in the left lung periphery. Bronchoscopic examination revealed left endobronchial bleeding. Computed tomography of the chest revealed a tumor shadow measuring 7cm in the left upper lobe and bilateral nodules with no lymphadenopathy. A systemic evaluation demonstrated no metastatic lesion. Patient underwent a left upper lobectomy. The diagnosis of CBPB was affirmed on anatomopathology of the tumor resection. Immunohistochemical studies showed that tumor cells were positive for vimentin, desmin, actin, Pan Cytokeratin and TTF-1. The final diagnosis was BPB classified as pathological T3N0M0 and no adjuvant treatment was associated. The patient showed good objective response with no evidence of disease recurrence still in 5 years surgery resection.

CONCLUSION

This case reiterates the importance of pathomorphological or immunohistochemical features in diagnosis of BPB.

18F-FDG PET/CT appearances of adult pulmonary blastoma

(18)F-FDG PET/CT scanning plays an important role in the management of thoracic malignancy. The authors would like to present FDG PET/CT images of a rare thoracic malignancy, pulmonary blastoma in adulthood. The patient had recurrent metastatic disease of previously resected primary pulmonary blastoma. The foci of recurrent metastases in lung, mediastinum, and subcutaneous tissue are intensely FDG-avid.

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.