Correction: Pleuropulmonary blastoma, not rhabdomyosarcoma in a congenital lung cyst

Multimodality treatment including whole pleura radiation therapy for DICER1-associated pediatric pleuropulmonary blastoma

Limited data are available regarding radiation therapy in pediatric pleuropulmonary blastoma (PPB). We report the case of a 3-year-old girl with type II PPB successfully treated with trimodality therapy including multiagent chemotherapy, resection, and whole pleura radiation therapy. While longer follow-up is required to confirm ultimate local tumor control and long-term post-treatment sequelae, currently 3.5 years following therapy, she is well, without recurrent disease or observable toxicity. The goal of this report is to add our experience to the literature regarding PPB, its management, and treatment, as prospective randomized controlled trials are not feasible due to the rarity of this disease.

Inequalities in diagnosis and registration of pediatric very rare tumors: a European study on pleuropulmonary blastoma

Very rare tumors (VRTs) account for up to 11% of childhood cancers. Dedicated national groups and registries only exist in some European countries. Pleuropulmonary blastoma (PPB) is a very rare intrathoracic pediatric tumor with a potentially severe prognosis. Due to its rarity, it sometimes goes unrecognized. We investigated PPB diagnostic capability and possible correlations between diagnostic performance and VRT-dedicated activities. The number of cases of PPB registered between 2000 and 2014 at pediatric oncology centers in Europe was compared with the number of expected cases. Data sources included VRT registries, population-based cancer registries, and hospital registries. Data were obtained for 25 countries, grouped into 4 geographical regions. The expected cases were 111, and the observed cases were 129. The observed-to-expected ratio was 1.86 for Northern Europe, 1.33 for Southern Europe, 1.22 for Central Europe, and 0.65 for Eastern Europe. More cases than expected were registered in all countries with an official VRT registry.Conclusion: The number of cases observed is consistent with expectations, but disparities exist across Europe. Difficulties in diagnosing PPB emerged in most Eastern countries. The incidence rate of PPB may be underestimated. The creation of VRT-dedicated groups and a European Registry for VRTs could help to reduce inequalities.What is Known:• Very rare pediatric tumors are often not recognized, despite representing almost 11% of childhood cancers .• Pleuropulmonary blastoma is a rare pediatric tumor with a poor prognosis.What is New:• The ability to diagnose and register pleuropulmonary blastoma varies in Europe.Registries dedicated to very rare pediatric tumors improve the diagnostic rates.• The incidence rate of pleuropulmonary blastoma may currently be underestimated.

Novel intronic DICER1 variation associated with pleuropulmonary blastoma in two siblings

Pleuropulmonary blastomas (PPB) are rare aggressive paediatric lung malignancies associated with DICER1 variants. We present two cases, a 2-year-old girl with upper respiratory tract symptoms as well as a 6-month-old girl sibling undergoing screening due to family history of malignancy. Imaging of the 2-year-old girl revealed a large mass filling the right hemithorax which was determined to be a type II PPB after pathological examination. Imaging of the 6-month-old sibling demonstrated a small cystic lesion in the posterior basal segment of the right lower lobe which was determined to be a type 1r PPB after pathological examination. The 2-year-old girl received adjuvant chemotherapy while the baby sister underwent resection alone and both are alive and well at 12 months and 7 months, respectively. Sequence analysis in both cases confirmed the same DICER1 variation, c.2437-2A>G (likely pathogenic), which has not been previously described in the literature.

Long-term outcomes of congenital lung malformations

Congenital lung malformations comprise a group of anatomical abnormalities of the respiratory tree including congenital cystic malformations, bronchopulmonary sequestrations, bronchogenic cyst, bronchial atresia, and congenital lobar emphysema. These anomalies are detected with increasing frequency by pre-natal sonography, but may also present for the first time with symptoms in childhood or later life. When symptomatic, there is little controversy that resection is indicated, which is usually curative. When a lesion is asymptomatic there is greater debate regarding the benefit of resection versus continued observation. This article provides an overview of the spectrum of disorders, the management options available and the long-term outcomes associated with each treatment option.

Risk-reduction surgery in pediatric surgical oncology: A perspective

OBJECTIVE

A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children.

METHODS

A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines".

RESULTS

We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2.

CONCLUSION

Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Clinicopathological and extensive immunohistochemical study of a type II pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a rare malignant dysontogenetic neoplasm primarily affecting younger children, even in newborns with an unfavorable outcome. PPB is histologically composed of a primitive, variably mixed blastematous and sarcomatous components, and exclusively subclassified as type I (purely cystic), type II (both cystic and solid elements) and type III (completely solid) by increasing histological evidence of malignancy. At present, well-documented cases or cases of truly precise presentation of either pathological or immunohistochemical findings in PPB are rare. The authors report one case of PPB in a 44-month-old child presenting as a solid and cystic mass with special emphasis on its radiological, histopathological and immunohistochemical aspects. The histological diagnosis was PPB, which would belong to the type II category.

DICER1 mutations in embryonal rhabdomyosarcomas from children with and without familial PPB-tumor predisposition syndrome

Embryonal rhabdomyosarcoma (ERMS) is the most common childhood sarcoma and is a component of the familial pleuropulmonary blastoma (PPB)-predisposition syndrome. Using the PPB model, we hypothesized that DICER1 mutations would be found in familial and sporadic forms of ERMS. Blood samples from four children with familial PPB and ERMS, and 52 sporadic ERMS tumors were tested for DICER1 mutations. Germline DICER1 mutations were found in all four patients with familial PPB and 2 of 52 (3.8%) sporadic ERMS had somatic mutations. Our findings confirm the pathogenetic relationship between ERMS and PPB suggesting that ERMS may result from abnormal miRNA regulation.

Pleuropulmonary blastoma: a single-institution experience

Pleuropulmonary blastoma (PPB) is a rare primary intrathoracic mesenchymal malignancy that occurs exclusively in early childhood. Twelve patients were diagnosed with PPB (1 type I, 5 type II, and 6 type III) between 1979 and 2009 at our institution. Upfront complete tumor resection was successful in 5 of 6 patients. Six patients had biopsy followed by neoadjuvant chemotherapy, 2 had complete tumor resection, and 2 had microscopic residual disease after surgery. All patients received vincristine, dactinomycin, and cyclophosphamide chemotherapy. Eight received additional chemotherapy with doxorubicin, cisplatin, etoposide, or ifosfamide. Three patients received local irradiation. The 5-year event-free and overall survivals were 33% ± 14% and 42% ± 14%, respectively. Median time to progression was 8 months. Five of 9 patients with gross total resection survived, whereas all 3 with gross residual disease died. Three of 5 survivors did not receive radiation. A high index of suspicion for PPB must be maintained in all patients diagnosed with intrathoracic sarcoma in early childhood. Gross total resection is necessary for cure, and selected patients do not require radiation therapy.

Congenital lung lesions

Confusion, controversy, and uncertainty are all terms applicable to the diagnosis and management of congenital lung lesions both prenatally and postnatally. This review examines the current status of fetal diagnosis and treatment of these lesions; reviews the various classifications, including congenital cystic adenomatoid malformation/congenital pulmonary airway malformation, sequestrations, variants and hybrid lesions; discusses the risk of malignant transformation or misdiagnosis with pleuropulmonary blastoma; presents the arguments in favor and against resection of asymptomatic lesions, the timing of such resection, and the long-term pulmonary function after resection; and reviews the experience with thoracoscopic resection of congenital lung lesions.

Is radical lobectomy required in congenital cystic adenomatoid malformation?

BACKGROUND

The extent of surgical resection in the management of congenital cystic adenomatoid malformation (CCAM) located in 1 pulmonary lobe remains controversial. Although lobectomy seems to be the best treatment to avoid recurrent pulmonary infection and neoplasia, neither retrospective nor prospective studies have been done to our knowledge. Besides, many reports claim that there are advantages of parenchyma-saving resections. The aim of our study was to determine whether it was necessary to perform an extended resection in these cases.

MATERIALS AND METHODS

We retrospectively reviewed all patients who had undergone a thoracoscopic lobectomy for CCAM located to 1 pulmonary lobe between January 2007 and January 2009. A thoracic radiologist performed a single blind review of all preoperative computed tomographic (CT) scans, mentioning the presence or absence of distant lesions from the main cysts of CCAM within the pulmonary lobe. The pathologist who analyzed the pulmonary lobectomy specimen was aware of the diagnosis but not the CT report.

RESULTS

Twenty-five patients underwent thoracoscopic lobectomy for congenital lung malformations, including 12 with CCAM. All had a positive prenatal sonogram. The median age at surgery was 12 months (range, 2-24 months). The preoperative CT showed only 2 cases with distant lesions within the affected pulmonary lobe, whereas the histologic study of the surgical specimen identified 6 cases. The sensitivity of the CT scan was low, 33%, whereas its specificity was high, 100%. Furthermore, the preoperative CT negative predictive value was 60%. The median time of follow-up was 7.5 months.

CONCLUSION

Adequate treatment of CCAM in children requires a lobectomy because of poor sensitivity and very poor negative predictive value (60%) of the preoperative CT to determine distal adjacent lesions. A prospective study on a larger number of patients is required to confirm these observations.

[Pleuropulmonary blastoma: a clinicopathological analysis]

背景与目的

胸膜肺母细胞瘤是一种罕见的且有其独特临床病理特征的恶性肿瘤，本文旨在探讨胸膜肺母细胞瘤的临床病理学特点及鉴别诊断等。

方法

收集5例胸膜肺母细胞瘤，复习患者临床资料，进行组织学及免疫组化观察，并结合文献复习分析。

结果

5例胸膜肺母细胞瘤患者年龄为21个月-47个月，平均为32.8个月；肿瘤主要位于胸腔，4例伴有胸腔积液。组织学观察：Ⅰ型胸膜肺母细胞瘤1例，呈单纯囊性；Ⅱ型胸膜肺母细胞瘤2例，呈囊实性，实性区伴横纹肌分化及灶性软骨样结节；Ⅲ型胸膜肺母细胞瘤2例，完全呈实性，可见间变性未分化肉瘤样成分。免疫组化染色显示肿瘤细胞呈Vimentin（+），部分肿瘤细胞呈Desmin和Myogenin（+），软骨样结节呈S-100（+）；PCK、EMA、CD99等均（-）。

结论

胸膜肺母细胞瘤是一种罕见的主要发生于婴幼儿肺和胸膜的高侵袭性恶性肿瘤，各亚型均有其临床病理学特点。诊断方面应与肺先天性囊性腺瘤样畸形、胚胎性横纹肌肉瘤等良恶性病变鉴别。

Primary lung tumors in children and adolescents: a 90-year experience

PURPOSE

Primary lung tumors in children are rare. A wide range of histopathologic tumor types occurs. The incidence of these lesions and their outcomes are still largely unknown. This study aims to determine the incidence of different primary lung tumors in children and to contribute data leading to the development of evidence-based treatment models.

METHODS

A single institution retrospective review was performed with institutional review board approval. Patients were included if they had primary, nonhematologic lung tumors. Simple squamous papillomas subjected to endoscopic biopsy and not resected, and vascular lesions associated with multisystem lesions, such as hereditary hemorrhagic telangiectasia, were excluded. Medical records and pathologic material for patients from 1918 to 2008 were reviewed.

RESULTS

Forty patients were identified (23 boys, 17 girls) with a mean age of 9.6 years (range, 3 months to 19 years). Fourteen distinct histopathologic tumor types were identified. The most common tumor types were carcinoid (8), inflammatory myofibroblastic tumor (7), and pleuropulmonary blastoma (6). Rare pediatric lung tumors including small cell carcinoma, adenocarcinoma, and pulmonary capillary hemangiomatosis were also seen. The mortality rate was 17.5% (7) in our series. Chemotherapy was used in 23% (9) and radiation in 20% (8) of the patients. Of the 33 survivors, 28 had follow-up with a median duration of 29.5 months (mean, 63.2 months; range, 1-471 months).

CONCLUSIONS

Primary lung tumors in children are rare and histopathologically diverse. The tumor spectrum involves many types not seen in adults, and unlike adults, patients rarely have a history of exposure to external predisposing factors. Although complete resection remains the standard for treatment of most tumors, addition of adjuvant therapy is dependent on both tumor stage and histopathologic type.

Fetal and placental malignancies: prenatal diagnosis and management

Fetal and placental malignancies are rare complications during pregnancy, but when they occur they may present significant challenges for the perinatology team. Owing to their rarity, there is limited information on many of these entities, with much data derived from individual case reports or small case series. Prenatal diagnosis of these entities is rare and inconsistent, usually in the form of isolated case reports. In the majority of fetal tumors, prenatal features are those of a mass lesion, with or without other non-specific features of fetal compromise such as polyhydramnios, fetal hydrops or intrauterine death, the final diagnosis in most cases being based on postnatal pathological examination.Expectant management is almost always indicated antenatally, with serial ultrasound examinations performed to detect rapid enlargement, metastasis or secondary fetal complications, such as non-immune hydrops, which may require intervention. Delivery should be planned in a specialist center in conjunction with pediatric surgeons and oncologists to allow appropriate neonatal management. Placental malignancy is most commonly in the form of gestatational trophoblastic disease, which requires assessment and management in specialist centers.

Pulmonary cysts in early childhood and the risk of malignancy

Surgery for congenital and early childhood lung cysts is often dictated by symptoms such as respiratory distress, infection or pneumothorax. Asymptomatic cysts present a therapeutic dilemma: surgical intervention and "conservative" observation have advocates. The risk of malignancy in such cysts is considered by some an indication for surgical intervention and is reviewed in this paper. Pleuropulmonary blastoma (PPB) is the most frequent malignancy associated with childhood lung cysts. Although rare, PPB occurs predictably in certain clinical and familial situations. This unique biology of PPB can inform the cyst management decision. The earliest manifestation of PPB is a malignant lung cyst in young children, clinically and radiographically indistinguishable from benign congenital lung cysts. Histopathologic examination differentiates cystic PPB from the benign cystic variants. Surgical excision of cystic PPB (with or without chemotherapy) cures approximately 85-90% of children. If not excised, cystic PPB evolves to cystic/solid or solid high-grade sarcoma (cure rate 45-60%) by age 2-6 years. Numerous reports of "malignancy in a congenital lung cyst" are now understood as the characteristic progression of cystic PPB. PPB is genetically determined in many cases. Detailed family history may reveal the hallmarks of PPB in the patient or young relatives: a unique constellation of diseases including lung cysts, cystic nephroma, childhood cancers, stromal sex-chord ovarian tumors, seminomas or dysgerminomas, intestinal polyps, thyroid hyperplasias, and hamartomas. Pneumothorax and multifocal/bilateral lung cysts also characterize PPB. These diagnoses predict that a lung cyst is more likely PPB than a benign congenital cyst. Patients fitting this pattern deserve histologic diagnosis. The genetic basis for this heritable syndrome is unknown but is being actively investigated.

Pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) is a dysontogenetic neoplasm of childhood that involves lung and/or pleura. There is an increased incidence of neoplasias and dysplasias among young relatives of children with PPB. Pathophysiologically, PPB evolves from a cystic to solid state over time. It is subclassified as type I (purely cystic), type II (both cystic and solid elements), and type III (completely solid). Type II and type III may be associated with metastasis, with the brain being the most common metastatic site. The absence of epithelial malignancy in PPB is a feature that distinguishes it from the adult-type pulmonary blastoma. The clinical presentation includes signs and symptoms associated with various respiratory disorders. To make a definitive diagnosis of PPB, an examination of the cystic fluid or solid tumor is required. Treatment for PPB consists primarily of surgery and chemotherapy. Nursing care is directed toward maintaining normal respiratory and neurological function, maintaining normal fluid and electrolyte balance, minimizing side effects associated with treatment, and providing education for the family.

Primary and metastatic lung tumors in the pediatric population: a review and 25-year experience at a large children's hospital

CONTEXT

Primary lung neoplasms are rare in children, but they comprise a broad and interesting spectrum of lesions, some of which are familiar from other tissue sites, and some of which are unique to the pediatric lung.

OBJECTIVE

To determine the relative incidence of primary and metastatic lung tumors in children and adolescents through a single-institution case series, to compare these data to reports in the medical literature, to discuss the clinical and pathologic features of primary tumors of the tracheobronchial tree and lung parenchyma in children, and to provide recommendations for handling pediatric lung cysts and tumors.

DATA SOURCES

A 25-year single institutional experience with pediatric lung tumors, based on surgical biopsies and resections at Texas Children's Hospital from June 1982 to May 2007, an additional 40 lung tumors referred in consultation, and a review of the medical literature.

CONCLUSIONS

A total of 204 pediatric lung tumors were diagnosed at our institution, including 20 primary benign lesions (9.8%), 14 primary malignant lesions (6.9%), and 170 secondary lung lesions (83.3%). The ratio of primary benign to primary malignant to secondary malignant neoplasms is 1.4:1:11.6. The common types of lung cancer in adults are exceptional occurrences in the pediatric population. The most common primary lung malignancies in children are pleuropulmonary blastoma and carcinoid tumor. Other primary pediatric lung tumors include congenital peribronchial myofibroblastic tumor and other myofibroblastic lesions, sarcomas, carcinoma, and mesothelioma. Children with primary or acquired immunodeficiency are at risk for Epstein-Barr virus-related smooth muscle tumors, lymphoma, and lymphoproliferative disorders. Metastatic lung tumors are relatively common in children and also comprise a spectrum of neoplasia distinct from the adult population.

Imaging findings in noncraniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. This paper is focuses on imaging for diagnosis, staging, and follow-up of noncraniofacial RMS.

Primary pulmonary rhabdomyosarcoma in a 5-month-old boy: a case report

Primary pulmonary rhabdomyosarcoma (RMS) in the pediatric population is a rare entity. A 5-month-old boy initially treated for pneumonia was proven to have a primary pulmonary RMS, which was resected via thoracotomy. After a course of chemotherapy following the Children's Oncology Group low-risk RMS protocol (ARST0331), a restaging chest computerized tomography scan showed local recurrence, which was also resected by open thoracotomy. The patient is currently undergoing local radiotherapy and salvage chemotherapy regimen. This patient is the youngest reported to date with this entity. The prognostic significance of his young age and the morphologic findings of his tumor are unclear.

Type I pleuropulmonary blastoma: pathology and biology study of 51 cases from the international pleuropulmonary blastoma registry

Pleuropulmonary blastoma (PPB) is a malignant neoplasm of the lung that presents in early childhood. The early form of the disease, cystic type I PPB, can be clinically and pathologically deceptive because of its resemblance to some developmental lung cysts. This study reviews 51 cases of type I PPB and 6 lung cysts from relatives of children with PPB. Type I PPB is a delicate multilocular cyst with variable numbers of primitive mesenchymal cells beneath a benign epithelial surface. Rhabdomyoblasts and cartilage nodules are seen in 49% and 40% of cases, respectively. Tumors in the youngest subset of patients, from birth to 2 months of age, are more uniform in composition and cellularity compared with those in older groups. Early tumors have a subtle transition between normal developing lung and tumor, showing bland interstitial mesenchymal cells uniformly expanding the alveolar septa. Presumed regressive changes including cyst wall necrosis are common. This phenomenon may explain the variable and sometimes sparse tumor cellularity seen in some type I PPBs. On a biologic level, this process supports the concept that not all type I PPBs are fated to progress to a type II or III PPB. Factors that control the balance between progression and regression may be important in predicting tumor behavior and determining which patients will benefit from adjuvant chemotherapy. In the meantime, recognition of this lesion as a neoplasm with malignant potential rather than a developmental cystic malformation is vital so the child can receive complete excision and appropriate follow-up care.