Gain of chromosome 8q is a frequent finding in pleuropulmonary blastoma

SIX1 as a Novel Immunohistochemical Marker in the Differential Diagnosis of Rhabdomyosarcoma

Background: Differential diagnosis of rhabdomyosarcoma (RMS) is challenging. Sineoculis homeobox homolog 1 (SIX1) is an oncogene involved in skeletal muscle differentiation. We compared protein expression patterns of SIX1 in RMS and its most common differential diagnoses. Methods: SIX1 immunohistochemistry in 36 RMS and in 33 tumors from seven differential diagnostic subtypes were evaluated. The fraction of SIX1 positive tumor cells was scored by three independent observers. Results: A majority (75%) of the evaluated RMS expressed SIX1 in at least 50% of tumor cells and all except one RMS had more than 25% positive tumor cells. Neuroblastoma had less than 1% SIX1 positive tumor cells. Gonadoblastoma, malignant rhabdoid tumor, and Ewing sarcoma had 10% or less positive tumor cells. Pleuropulmonary blastoma exhibited 26-50% positive tumor cells and synovial sarcoma >50% positive cells. Conclusion: SIX1 immunohistochemistry is positive in most RMS, and occasionally in some tumors within the differential diagnoses of RMS.

Phenotypic similarities within the morphologic spectrum of DICER1-associated sarcomas and pleuropulmonary blastoma: Histopathologic features guide diagnosis in the LMIC setting

Extrapulmonary DICER1-associated sarcomas (DS) can harbor morphological features overlapping with pleuropulmonary blastoma. We report three children with intracranial and genital tract sarcomas, suspected to have DS based on a heterogeneous yet defining combination of spindle-cell sarcomatous and blastemal morphology, with rhabdomyomatous differentiation. Foci of immature cartilage at diagnosis (n = 2/3) and increased neuroepithelial differentiation at recurrence (n = 1) were noted. Morphological suspicion prompted somatic testing at reference centers, confirming likely biallelic, loss-of-function, and "hotspot" missense DICER1 variants in all three tumors. This can serve as a model for this diagnosis in resource-limited settings and has implications for germline testing, surveillance, and tumor management.

Multimodality Imaging of Pleuropulmonary Blastoma: Pearls, Pitfalls, and Differential Diagnosis

Pleuropulmonary blastomas are rare, potentially aggressive embryonal cancers of the lung parenchyma and pleural surfaces that account for 0.25%-0.5% of primary pulmonary malignancies in children. Pleuropulmonary blastomas are classified as cystic (type I), mixed cystic and solid (type II), and solid (type III). Pleuropulmonary blastoma occurs in the same age group (0-6 years) as other more common solid tumors such as neuroblastoma and Wilms tumor. Differential diagnosis includes metastasis from Wilms tumor and macrocystic congenital pulmonary airway malformation (CPAM). A key pathologic and genetic discriminator is the DICER1 germline mutation found in patients with pleuropulmonary blastoma. Imaging, histopathologic, and clinical data are important to use in conjunction in order to determine the diagnosis and risk stratification of pleuropulmonary blastomas. Survival varies from poor to good, depending on type. However, the spectrum of pleuropulmonary blastoma is insufficiently understood due to the variable presentation of this rare disease. We present a current review of the literature regarding pleuropulmonary blastomas in this article.

Metadherin (MTDH) overexpression significantly correlates with advanced tumor grade and stages among colorectal cancer patients

BACKGROUND

Colorectal cancer is the 4th leading cause of cancer related deaths affecting both men and women worldwide. In the present study, any probable role of MTDH mRNA expression in CRC tumorigenesis was explored using both discovery and validation cohorts.

METHODS AND RESULTS

After prior ethical and biosafety approvals, tumor tissue samples along with their adjacent controls were collected for this study from Pakistani patients diagnosed with colorectal cancer. RNA was isolated using Trizol reagent, followed by cDNA synthesis. Transcript analysis of MTDH was performed by using qPCR. Moreover, genome-wide expression of MTDH was also determined through micro-array data analysis using BRB-array tools software. MTDH expression was significantly high in tumor tissue samples (p < 0.05) compared to their respective controls. Likewise, results of microarray analysis also revealed overamplification of MTDH in tumor samples as compared to controls. Expression of MTDH was also found to be positively correlated with KI-67 index (p < 0.05) and were observed to be significantly upregulated in advance tumor grade (p < 0.05) and stage (p < 0.05). However, no association of MTDH overexpression with age and gender could be established.

CONCLUSION

Hence, it can be concluded that MTDH is a core element that plays a pivotal role in colorectal tumorigenesis irrespective of patient's age and gender. Molecular insight into the tumor microenvironment revealed MTDH as a niche, representing distinctive framework for cancer progression, thus, making it an innovative target strategy for colorectal cancer treatment.

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.

Rhabdoid Tumor Predisposition Syndrome and Pleuropulmonary Blastoma Syndrome

In recent years, hereditary cancer syndromes have developed greater interest in the scientific community. Two such syndromes, rhabdoid tumor syndrome and pleuropulmonary blastoma (DICER1) syndrome, have appeared increasingly in the literature. This review will discuss these two syndromes in terms of clinical parameters, associated tumors, and genetic associations.

Chromosome 8q as the most frequent target for amplification in early gastric carcinoma

Early gastric carcinoma (GC) is considered to be a curable cancer, as it progresses to the advanced stage following varying durations. Understanding the early stage of GC may provide an insight into its pathogenesis and contribute to reducing the mortality rate of this disease. To investigate the genomic aberrations associated with 22 cases of early GC, high-density microarray comparative genomic hybridization was performed in the present study. The most notable finding was copy number gains (log₂ ratio >0.25) on the long arm of chromosome 8, which occurred in 77.3% (17/22) of GC cases, and the delineated minimal common region was 8q22.1-q24.3. More specifically, two amplified (log₂ ratio >1) loci in the 8q22.1-q24.3 region were detected in 18.2% (4/22) of GC cases. The first loci covered a region of 102.4–107.9 kb, mapping on 8q22.3-q23.1, and comprised the transcription factor CP2-like 3 gene. The second loci, spanning 128.7–145.7 kb on 8q24.21-q24.3, comprised the representative oncogene of myelocytomatosis. Furthermore, the following possible target genes that were not previously considered to play a pathogenic role in GC were identified: Plasmacytoma variant translocation 1, cysteine/histidine rich 1, kinesin family member C2, forkhead box H1, protein phosphatase 1 regulatory subunit 16A, glutamic-pyruvate transaminase, LOC113655 and RecQ protein-like 4. In the present study, previous findings showing that 8q mutations accumulate early during the multistage pathogenesis of GC were confirmed and expanded upon. The confirmation of previously reported 8q gains and the identification of novel target genes at 8q22.1-q24.3 amplified chromosomal sites should aid in improving our understanding of the molecular mechanisms underlying the tumorigenesis of early GC.

FGF10 Signaling differences between type I pleuropulmonary blastoma and congenital cystic adenomatoid malformation

Background

Type I pleuropulmonary blastoma (PPB) and congenital cystic adenomatoid malformation of the lung (CCAM) are cystic lung diseases of childhood. Their clinical and radiological presentations are often similar, and pathologic discrimination remains difficult in many cases. As a consequence, type I PPB and CCAM are frequently confused, leading to delayed adequate management for type I PPB. Recent studies have suggested a role for fibroblast growth factor (FGF) 10 signal pathway in CCAM pathogenesis. The objective of our study was to determine whether FGF10 signaling differs between CCAM and type I PPB.

Methods

Immunohistochemical studies were performed for expression of FGF10, its receptor FGFR2b, and its inhibitor sonic hedgehog (SHH) in focal type I PPB (n=6), CCAM type I (n=7), CCAM type II (n=7), and control lungs (n=5).

Results

FGF10, FGFR2b, and SHH expressions differed markedly between type I PPB and both types of CCAM. Type I and type II CCAM cystic walls expressed FGF10, FGFR2b, and SHH, whereas staining was absent or poor in type I PBB cystic walls. Expression of FGF10, FGFR2b, and SHH did not differ between CCAM cystic walls and control airway walls.

Conclusions

These findings show that immunohistochemistry with FGF10, FGFR2b, or SHH could be useful in differentiating CCAM from type I PPB, when a child presents with a focal cystic lung lesion. The absence of strong expression of FGF10, FGFR2b, and/or SHH makes the diagnosis of CCAM very doubtful.

Shall all congenital cystic lung malformations be removed? the case in favour

The need to systematically remove congenital cystic lung lesions is based on three main arguments. First, cystic malformations are often considered as congenital cystic adenomatoid malformations (CCAM), while other less favorable diagnoses are possible, such as pleuropulmonary blastoma. Only postsurgical pathological analysis allows diagnosis. Second, there are clinical and biological arguments for considering macrocystic lesions as likely to degenerate. The only prevention is surgical removal. Finally, there is no recommendation on how to follow these children, in the absence of removal, causing unnecessary family stress. This seems unjustified, compared to a feasibility of thoracoscopic removal in most cases.

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.