Pleuropulmonary blastoma: cytogenetic and spectral karyotype analysis

Whole genome profiling of rare pediatric thoracic tumors elucidates a YAP1::LEUTX fusion in an unclassified biphasic embryonal neoplasm

Malignant biphasic tumors of the lungs are rare, more so in the pediatric population. Here, we present the whole-genome characterization of a pleuropulmonary blastoma Type III and an unclassified biphasic thoracic embryonal neoplasm. The pleuropulmonary blastoma harbored pathogenic DICER1 germline and somatic mutations, and additional somatic variants in TP53 and BCOR. The other malignant tumor demonstrated a t(11;19) balanced translocation with a YAP1::LEUTX fusion that was confirmed by fluorescence in situ hybridization. No DICER1 germline or somatic mutation was present. YAP1 and LEUTX have been implicated in tumorigenesis of various neoplasms, and YAP1 fusion genes are an emerging oncogenic entity in a variety of malignancies. In this study we highlight the importance of whole-genome characterization of rare and unclassified tumors to identify biologic mechanisms and potential therapeutic targets.

Establishment and Characterization of a Novel Pleuropulmonary Blastoma Cell Line

PURPOSE

Pleuropulmonary blastoma (PPB) is an infrequently encountered childhood malignant intrathoracic neoplasm associated with unfavorable clinical behavior. Since a well-characterized preclinical model is essential for developing competent agents for PPB, we aim to establish and characterize the world's first cell line of PPB, and attempt to perform the cytotoxicity assay on the PPB cell line.

EXPERIMENTAL DESIGN

The index case is a 2-year-old female who developed a right thoracic tumor that was surgically removed and treated with multi-agent chemotherapy. The patient is free from recurrence, although it was 9 years after the diagnosis when she developed a thyroid tumor. We performed in vitro cultivation of the isolated neoplastic cells from the tumor, cytogenetic findings and molecular analysis, and tetrazolium colorimetric assay.

RESULT

The histology was consistent with PPB. Serial passage of cultivation produced a continuously growing cell line, KCMC-PPB-1. Conventional cytogenetic analysis of the established cell line revealed complex numerical and structural chromosomal abnormalities, including add(17)(p11). Mutation analysis on the cultured cells revealed amino-acid substitution mutation on exon 4 of TP53 (NM_001276760.3:c.212_213delTG; NP_001263689.1:p.Leu72ArgfsTer37) and compound heterozygous mutations of DICER1 (NM_177438.3:c. 4910C>A; NP_803187.1:Ser1637* and NM_177438.3:c. 5114A>T; NP_803187.1:Glu1705Val). The cultivated cells demonstrated vulnerability to bortezomib on cytotoxicity assay.

CONCLUSION

Our KCMC-PPB-1 is the first genuine, molecularly characterized PPB cell line. The cell line is transplantable to nu/nu mice; therefore, it is suitable for a preclinical model for new drug development. The cytotoxicity assay demonstrated that bortezomib is active in the current PPB model.

Strong Expression and Amplification of IGF1R in Pleuropulmonary Blastomas

Pleuropulmonary blastoma (PPB) is a rare malignant intrathoracic tumor primarily affecting children under 5 years of age. PPBs are histologically divided into 3 subtypes: Type 1 PPBs are composed of multiple cysts, and type 3 is a solid lesion with a variable morphologic appearance. Type 2 has a mixed morphology consisting of cystic and solid areas. The genetics of PPB are poorly understood. We analyzed 16 cases of the Kiel Paediatric Tumor Registry with the diagnosis of PPB by comparative genomic hybridization and confirmed some genetic changes by fluorescence in situ hybridization. Furthermore, we performed immunohistochemistry to evaluate insulin-like growth factor type 1 (IGF1R) protein expression. Frequent findings by comparative genomic hybridization were losses on 4q, 5q, 9p and gains on chromosome 8, 17, and 20q. Genomic amplification was observed in 5 cases, 4 related to 15q25qter and 1 to 1p. Fluorescence in situ hybridization could confirm 7 gains of chromosome 8 (7/16, 44%) and 4 amplifications of the IGF1R-gene on 15q26 (4/16, 25%). All of the tumors with IGF1R amplification were type 3 PPBs. One of the PPBs with gain of chromosome 8 was a type 2 tumor and 6 tumors were type 3 PPBs. All but one PPB showed an IGF1R expression by immunohistochemistry. In our series of 16 PPBs, 25% of the tumors have an amplification of the IGF1R gene and 44% show a gain of chromosome 8. All of the tumors with IGF1R amplification were PPBs type 3, indicating that it is a later event in tumor progression, while the gain of chromosome 8 was found in both type 2 and type 3 tumors indicating that these changes are probably earlier events in tumor development. Furthermore, the strong IGF1R protein expression could be a possible therapeutic target in refractory chemoresistant PPBs.

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.

Translocation t(12;17)(q24.1;q21) as the sole anomaly in a nasal chondromesenchymal hamartoma arising in a patient with pleuropulmonary blastoma

The identification of recurrent chromosomal abnormalities in benign and malignant mesenchymal neoplasms has provided important pathogenetic insight as well as powerful diagnostic adjuncts. Nasal chondromesenchymal hamartoma (NCMH), an extremely rare benign tumor arising in the sinonasal tract of infants and children, has not been previously subjected to cytogenetic analysis. Histopathologically composed of mixed mesenchymal elements, NCMH exhibits a relatively wide differential diagnosis to include chondromyxoid fibroma, chondroblastoma, aneurysmal bone cyst, fibrous dysplasia, and osteochondromyxoma. An interesting association with pleuropulmonary blastoma has been reported in a small subset of NCMH patients. In the current study, cytogenetic analysis of a NCMH arising in an 11-year-old boy with a past medical history of pleuropulmonary blastoma revealed a novel 12;17 translocation, t(12;17)(q24.1;q21), as the sole anomaly.

Pleuropulmonary blastoma as characteristic cause of pneumothorax

BACKGROUND

Pleuropulmonary blastoma (PPB) is the most common lung neoplasms in childhood. Usually presents as recurrent respiratory infections and in some cases as pneumothorax.

CASE REPORT

We report the case of a 2-year-old patient that was diagnosed with PPB, that first manifested as recurrent pneumothorax. Three chest computed tomography were necessary for the diagnosis. The first 2 tomographies showed no abnormalities suggestive of malignancy. The patient had a family history of both PPB and leukemia. Three years and a half after completion of treatment, the patient is in complete remission.

CONCLUSIONS

PPB is an uncommon disease but is the most common pulmonary neoplasms in childhood. We must suspect it in patients with a suggestive family history and recurrent pneumothorax in the same location.

Thirteen-year-old child with a malignant chest tumor: clinicopathologic conference

A case of pleuropulmonary blastoma in a 13-year-old child, exposed to the Chernobyl disaster while in-utero, is presented and discussed by both clinician and pathologist, in this traditional clinical-pathologic conference. The discussion includes the differential diagnoses of chest mass in children.

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.