Expansion of tumor-infiltrating lymphocytes in non-small cell lung cancer: Clinical potential and efficacy in EGFR mutation subsets.

Our study aimed to expand tumor-infiltrating lymphocytes (TILs) from primary non-small cell lung cancers (NSCLCs) and evaluate their reactivity against tumor cells. We expanded TILs from 103 primary NSCLCs using histopathological analysis, flow cytometry, IFN-γ release assays, cell-mediated cytotoxicity assays, and in vivo efficacy tests. TIL expansion was observed in all cases, regardless of EGFR mutation status. There was also an increase in the median CD4+/CD8+ ratio during expansion. In post-rapid expansion protocol (REP) TILs, 13 out of 16 cases, including all three cases with EGFR mutations, exhibited a two-fold or greater increase in IFN-γ secretion. The cytotoxicity assay revealed enhanced tumor cell death in three of the seven cases, two of which had EGFR mutations. In vivo functional testing in a patient-derived xenograft model showed a reduction in tumor volume. The anti-tumor activity of post-REP TILs underscores their potential as a therapeutic option for advanced NSCLC, irrespective of mutation status.

The causal relationship of serum uric acid on colorectal cancer: A Mendelian randomization study.

Colorectal cancer (CRC) is a significant public health issue owing to its widespread occurrence and substantial morbidity and mortality rates. Recent studies have highlighted serum uric acid (SUA) level as a probable risk factor for CRC; however, the inconsistency in these findings has created doubt. We performed a Mendelian randomization (MR) study utilizing extensive cohort data from the UK BioBank and the NHGRI-EBI Genome-Wide Association Study (GWAS) Catalog to investigate the causal connection between SUA levels and CRC incidence. Our MR study addresses the constraints of earlier studies, including limited sample sizes and inconsistent results. Considering SUA levels as the exposure and CRC as the outcome, the inverse variance-weighted (IVW) approach in MR showed that the odds ratios (ORs) for CRC for each unit increase in SUA were 0.232 (95% confidence interval [CI] of OR 0.094-0.570; P = .001) and 0.551 (95% CI of OR 0.325-0.934; P = .027). Pleiotropic tests and sensitivity analysis confirmed minimal horizontal pleiotropy and the robustness of causality. Our research deepens the understanding of the association between SUA levels and CRC, offering insights into prevention strategies and patient outcomes prediction.

Luminal androgen receptor subtype and tumor-infiltrating lymphocytes groups based on triple-negative breast cancer molecular subclassification.

In our previous study, we developed a triple-negative breast cancer (TNBC) subtype classification that correlated with the TNBC molecular subclassification. In this study, we aimed to evaluate the predictor variables of this subtype classification on the whole slide and to validate the model's performance by using an external test set. We explored the characteristics of this subtype classification and investigated genomic alterations, including genomic scar signature scores. First, TNBC was classified into the luminal androgen receptor (LAR) and non-luminal androgen receptor (non-LAR) subtypes based on the AR Allred score (≥ 6 and < 6, respectively). Then, the non-LAR subtype was further classified into the lymphocyte-predominant (LP), lymphocyte-intermediate (LI), and lymphocyte-depleted (LD) groups based on stromal tumor-infiltrating lymphocytes (TILs) (< 20%, > 20% but < 60%, and ≥ 60%, respectively). This classification showed fair agreement with the molecular classification in the test set. The LAR subtype was characterized by a high rate of PIK3CA mutation, CD274 (encodes PD-L1) and PDCD1LG2 (encodes PD-L2) deletion, and a low homologous recombination deficiency (HRD) score. The non-LAR LD TIL group was characterized by a high frequency of NOTCH2 and MYC amplification and a high HRD score.

Mechanistic Insights of Copper Catalyzed Trifluoromethyl Aziridine Opening: Regioselective and Stereospecific Aryl Grignard Addition.

The copper catalyzed regioselective and stereospecific opening of CF3-aziridines is reported. This method focuses on the synthesis of α-CF3-ß-arylethylamines, which can be potential key intermediates in the synthesis of synthetic analogues and biologically active molecules. Density functional theory calculations reveal the nature of the active copper species and the role of the LiClMgX2 (X = Cl or I) as a Lewis acid. Further, the computed mechanism accounts for the high regioselectivity of this transformation.

Processing of Shakespearean functional shift as a semantic anomaly in L2 English: Evidence from an ERP study.

Functional shift, a productive word formation in English, converts the functional status of a word without changing its form. A previous event-related potential study reported that functional shift elicited left anterior negativity (LAN) and P600 effects in first language processing, suggesting that shifted words triggered syntactic processes in native English speakers. Using the same materials and experimental methods, this study investigated the processing of functional shift in English as a second language, asking Korean learners of English to make acceptability judgments of sentences containing a functional shift, a semantic incongruity, a double violation, or no violation. The results revealed that functional shift elicited significant N400 effects, indicating that Korean participants processed functionally shifted words as semantic anomalies. Our finding points to the possibility that the mental representation of functional shift differs in L1 and L2.

Enhanced Risk Stratification in Early-Stage Endometrial Cancer: Integrating POLE through Droplet Digital PCR and L1CAM.

AIM: In order to enhance risk stratification in early-stage endometrial cancer (EC), we conducted molecular classification using surrogate markers, including the POLE droplet digital polymerase chain reaction (ddPCR) and L1CAM immunohistochemistry (IHC). METHOD: We analyzed archival tumor tissue from 183 early-stage EC patients. POLE pathogenic mutations of P286R, V411L, S297F, A456P, and S459F within exons 9, 13, and 14 were detected using a ddPCR, while the mismatch repair (MMR) status was determined by MMR protein IHC and MSI tests. Additionally, we conducted IHC for p53 and L1CAM. RESULTS: The 183 ECs were categorized into four subgroups: POLE-mutated (15.9%), MMR-deficient (29.0%), p53-abnormal (8.7%), and non-specific molecular profile (NSMP, 46.4%). We further subcategorized the NSMP subgroup into NSMP-L1CAMneg (41.5%) and NSMP-L1CAMpos (4.9%), which we refer to as the molecular L1CAM classification. The molecular L1CAM classification was an independent prognostic factor for recurrence-free survival (RFS) and overall survival (OS) (p < 0.001, each). CONCLUSION: Integrating molecular L1CAM classification can enhance risk stratification in early-stage EC, providing valuable prognostic information to guide treatment decisions and improve patient outcomes. POLE ddPCR might be a cost-effective and easy-to-perform test as an alternative to POLE NGS.

Clinicopathologic characterization of cervical metastasis from an unknown primary tumor: a multicenter study in Korea.

BACKGROUND: Research regarding cervical metastasis from an unknown primary tumor (CUP) according to human papillomavirus (HPV) and Epstein-Barr virus (EBV) status in Korea has been sporadic and small-scale. This study aims to analyze and understand the characteristics of CUP in Korea according to viral and p16 and p53 status through a multicenter study. METHODS: Ninety-five cases of CUP retrieved from six hospitals in Korea between January 2006 and December 2016 were subjected to high-risk HPV detection (DNA in situ hybridization [ISH] or real-time polymerase chain reaction), EBV detection (ISH), and immunohistochemistry for p16 and p53. RESULTS: CUP was HPV-related in 37 cases (38.9%), EBV-related in five cases (5.3%), and unrelated to HPV or EBV in 46 cases (48.4%). HPV-related CUP cases had the best overall survival (OS) (p = .004). According to the multivariate analysis, virus-unrelated disease (p = .023) and longer smoking duration (p < .005) were prognostic factors for poor OS. Cystic change (p = .016) and basaloid pattern (p < .001) were more frequent in HPV-related cases, and lymphoepithelial lesion was frequent in EBV-related cases (p = .010). There was no significant association between viral status and p53 positivity (p = .341), smoking status (p = .728), or smoking duration (p = .187). Korean data differ from Western data in the absence of an association among HPV, p53 positivity, and smoking history. CONCLUSIONS: Virus-unrelated CUP in Korea had the highest frequency among all CUP cases. HPV-related CUP is similar to HPV-mediated oropharyngeal cancer and EBVrelated CUP is similar to nasopharyngeal cancer in terms of characteristics, respectively.

A Case Report of HER2-Amplification in the Breast Without Histological Abnormality.

Atypical ductal hyperplasia and low-grade ductal carcinoma in situ (DCIS) are regarded as precursor lesions of estrogen receptor (ER)-positive invasive breast cancer. In HER2-amplified invasive breast cancer, a precursor lesion before DCIS has not yet been described. Here we introduce a case of HER2-positive lobules in the breast without histological abnormality. A 39-year-old premenopausal woman visited a hospital due to identification of microcalcifications on screening mammography. The subsequent biopsy confirmed high-grade DCIS. She underwent wide excision, and a residual high-grade DCIS with a size of 1.4 cm was found. The tumor cells were hormone receptor positive and HER2 negative on immunohistochemical (IHC) staining. Around DCIS, there were terminal duct lobular units (TDLUs) showing strong HER2 positivity on IHC. These HER2-positive lobules were 7 mm away from the high-grade DCIS and was 1.1 mm in size. These HER2-positive lobules showed no histologic abnormality and had no difference compared with the surrounding normal TDLUs. Nevertheless, in addition to showing HER2 overexpression in IHC, HER2 amplification was also identified in HER2 silver in situ hybridization. HER2 amplification plays an important role in breast cancer development, and HER2 amplification is known to occur as an early event in cancer development. There have been studies identifying driver mutations in normal tissues of other organs. These findings suggest that HER2 amplification in the breast without histological abnormality could occur, and the HER2-positive lobules could be "at risk" for transformation into the precursor lesion of HER2-positive breast cancer, although the biological significance of these findings is unclear.

A Korean male with Kleefstra syndrome presented with micropenis.

Kleefstra syndrome is caused by chromosome 9q34.3 deletion or heterozygous mutations in the euchromatin histone methyl transferase 1 (EHMT1) gene. It can be accompanied by intellectual disability, distinctive facial features, microcephaly, psychiatric disorders, hypotonia in childhood, hearing loss, heart defects, renal defects, epilepsy, speech anomalies, and obesity. Furthermore, genital anomalies are present in 30%-40% of male patients with Kleefstra syndrome, but their mechanisms have not been elucidated. Herein, we report a patient with Kleefstra syndrome presenting with micropenis. The patient was transferred to Kyungpook National University Children's Hospital for management of imperforate anus on the day of birth. Physical examination revealed micropenis with stretched penile length of 0.9 cm and facial dysmorphisms, including hypertelorism and anteverted nares. Chromosomal microarray revealed 424-kb heterozygous deletion at chromosome 9q34.3 (arr[hg19] 9q34.3 (140,234,315-140,659,055)x1). Among the involved main OMIM genes, phenotypically relevant genes were EHMT1 and NSMF. Endocrinological investigation showed low basal gonadotropin and testosterone levels. Anterior pituitary hormones and steroid hormone levels were in the normal range. Testicular function was normal based on human chorionic gonadotropin stimulation test. The patient experienced improvement in penile length growth with intramuscular testosterone enanthate injection initiated at 4 months of age. The purpose of this study is to describe the etiology, endocrine laboratory tests, and treatment of micropenis in Kleefstra syndrome.

A general approach to identify cell-permeable and synthetic anti-CRISPR small molecules.

The need to control the activity and fidelity of CRISPR-associated nucleases has resulted in a demand for inhibitory anti-CRISPR molecules. The small-molecule inhibitor discovery platforms available at present are not generalizable to multiple nuclease classes, only target the initial step in the catalytic activity and require high concentrations of nuclease, resulting in inhibitors with suboptimal attributes, including poor potency. Here we report a high-throughput discovery pipeline consisting of a fluorescence resonance energy transfer-based assay that is generalizable to contemporary and emerging nucleases, operates at low nuclease concentrations and targets all catalytic steps. We applied this pipeline to identify BRD7586, a cell-permeable small-molecule inhibitor of SpCas9 that is twofold more potent than other inhibitors identified to date. Furthermore, unlike the reported inhibitors, BRD7586 enhanced SpCas9 specificity and its activity was independent of the genomic loci, DNA-repair pathway or mode of nuclease delivery. Overall, these studies describe a general pipeline to identify inhibitors of contemporary and emerging CRISPR-associated nucleases.

SARS-CoV-2 spike trimer vaccine expressed in Nicotiana benthamiana adjuvanted with Alum elicits protective immune responses in mice.

The ongoing coronavirus disease 2019 (COVID-19) pandemic has spurred rapid development of vaccines as part of the public health response. However, the general strategy used to construct recombinant trimeric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) proteins in mammalian cells is not completely adaptive to molecular farming. Therefore, we generated several constructs of recombinant S proteins for high expression in Nicotiana benthamiana. Intramuscular injection of N. benthamiana-expressed Sct vaccine (NSct Vac) into Balb/c mice elicited both humoral and cellular immune responses, and booster doses increased neutralizing antibody titres. In human angiotensin-converting enzyme knock-in mice, two doses of NSct Vac induced anti-S and neutralizing antibodies, which cross-neutralized Alpha, Beta, Delta and Omicron variants. Survival rates after lethal challenge with SARS-CoV-2 were up to 80%, without significant body weight loss, and viral titres in lung tissue fell rapidly, with no infectious virus detectable at 7-day post-infection. Thus, plant-derived NSct Vac could be a candidate COVID-19 vaccine.

Metanephrine Negative Pheochromocytoma: A rare case report of dopamine-secreting tumor in an adolescent patient with NF1.

Pheochromocytoma (PCC) occurs in 4% of pediatric neurofibromatosis type 1 (NF1) patients and is mostly characterized by epinephrine and norepinephrine secretion. Herein, we report the first case of a dopamine-secreting PCC in a 13-year-old patient with NF1, in whom a left adrenal mass was incidentally found on abdominal computed tomography (CT) during hypertension workup. Fractionated 24-h urine metanephrine excretion was normal but urine dopamine level was elevated. On 123I-metaiodobenzylguanidine (MIBG) single photon emission tomography/CT (SPECT/CT), focal MIBG uptake was observed. Our multidisciplinary team determined that surgery would be difficult to perform because the tumor was small and the symptoms were vague, with only increased dopamine level. After six months, the tumor increased in size on abdominal CT, with focal significant uptake of the lesion on 6-[18F]fluoro-L-3,4-dihydroxyphenylalanine (18F-FDOPA) PET/CT. Laparoscopic resection was performed, and the mass was histologically confirmed as PCC. Currently, the vital signs of the patient are stable, urine dopamine levels are normal, and there is no abnormal uptake of 18F-FDOPA PET/CT. This study reports a case of a rare dopamine-secreting PCC. When metanephrine is negative in patients at high risk of PCC, focused examination and multidisciplinary approach are needed.

The effects of a mobile application for patient participation to improve patient safety.

BACKGROUND: Patient participation in patient safety activities in care processes is a fundamental element of safer care. Patients play an important role in preventing patient safety incidents and improving health outcomes. Therefore, healthcare providers need to develop and provide educational materials and actionable tools for patient participation. OBJECTIVES: This study aimed to develop a mobile application for health consumers' participation and evaluate the effect of the mobile application on improving health consumers' participation in patient safety. METHODS: A quasi-experimental design was adopted. We developed a mobile application on the basis of a needs assessment, literature review, compilation of patient safety topics, and validity testing of the application. The target population included Korean adults aged between 30 and 65 years who had visited a medical institution more than once within the most recent 6 months. The intervention group received patient participation training by using the mobile application, Application for Patient Participation in Safety Enhancement, for 2 months. The primary outcome variables were patient safety knowledge, self-efficacy of participation, willingness to participate and experience of patient participation in patient safety activities. End-user satisfaction was assessed using a questionnaire. To assess participants' experiences with the intervention, qualitative data were collected through a focus group interview and open-ended responses to an end-user satisfaction survey. RESULTS: The intervention group (n = 60) had significantly higher overall average scores than the control group (n = 37) with regard to patient safety knowledge (p < .001), self-efficacy of participation (p = .001), willingness to participate (p = .010) and experience of participation (p = .038) in the post-survey. The total mean end-user satisfaction score was 3.56 ± 0.60. The participants expressed the realization that patients could play an important role in improving patient safety. CONCLUSIONS: This study demonstrated that educating health consumers through a mobile application with useful information improves patient participation in patient safety activities. Educational materials and patient participation tools could motivate health consumers' health-related behaviours. PATIENT OR PUBLIC CONTRIBUTION: Patients were involved during the programme development and evaluation.

Copper Catalyzed Regioselective and Stereospecific Aziridine Opening with Pyridyl Grignard Nucleophiles.

Copper catalyzed regioselective and stereospecific coupling between aziridines and in situ generated pyridine Grignard reagents is reported. This method provides ß-pyridylethylamines with diverse structures and functionalities from aziridines and iodopyridines. ß-Pyridylethylamines are potential scaffolds for the synthesis of biologically active compounds often found in pharmaceuticals. The synthesis of challenging chiral dihydroazaindoles was also achieved through mild one-pot reaction conditions via aziridine opening followed by nucleophilic cyclization.

Alternative approaches utilizing click chemistry to develop next-generation analogs of solithromycin.

The marked rise in bacterial drug resistance has created an urgent need for novel antibacterials belonging to new drug classes and ideally possessing new mechanisms of action. The superior biological activity of solithromycin against streptococci and other bacteria causative of community-acquired pneumonia pathogens, compared to telithromycin and other macrolides encouraged us to extensively explore this class of antibiotics. We, thus, present the design and synthesis of a novel series of solithromycin analogs. Three main strategies were pursued in structure-activity relationship studies covering the N-11 side chain and the desosamine motif, which are both chief elements for establishing strong interactions with the bacterial ribosome as the molecular target. Minimal inhibitory concentration assays were determined to assess the in vitro potency of the various analogs in relation to solithromycin. Two analogs exhibited improved activity compared to solithromycin against resistant strains, which can be assessed in further pre-clinical studies.

Communication education regarding patient safety for registered nurses in acute hospital settings: a scoping review protocol.

INTRODUCTION: The importance of correct and timely communication continues to be emphasised in the area of patient safety. Nurses play a key role in communicating with a variety of healthcare personnel to deliver safe care for patients. Many attempts have been made to improve nursing professionals' communication competencies regarding patient safety. However, the scope, method and effectiveness of communication education regarding patient safety for registered nurses have not been sufficiently reviewed. In order to understand the overall status of this field, a scoping review with a systematic framework is necessary. The objective of this study is to map the extent, range and nature of literature on communication education regarding patient safety for registered nurses in acute hospital settings and identify gaps to guide future research, policy and practice. METHODS AND ANALYSIS: This study will be conducted in accordance with the methodology for scoping reviews developed by Arksey and O'Malley. To strengthen its rigour, the scoping review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. The overall review process will involve an independent review by two reviewers to select and analyse literature. The databases to be explored are MEDLINE (Ovid), Embase, Education Resources Information Center (ERIC), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the Korean Medical Database (KMBASE). In addition, we will endeavour to include the grey literature through manual searches on patient safety-related websites. This review will target literature on communication programmes for patient safety provided to registered nurses in acute hospital settings and will include peer-reviewed literature in English and Korean since 2000, when research in the field of patient safety started to increase rapidly. ETHICS AND DISSEMINATION: Since this study is a review of previous studies, no ethics approval is required. The findings of the study will be disseminated in a peer-reviewed journal for publication.

Phenotypic Differences of CD103+ Tissue-Resident Memory T Cells Associated with Various Cancers.

BACKGROUND/AIMS: The presence and clinical importance of tissue-resident memory T (TRM) cells have been recently described in association with various cancer types. However, the frequency and the traditional naïve-effector-memory phenotypic characteristics of TRM cells are largely unknown. METHODS: We analyzed single-cell populations of colorectal cancer (CC, n = 18), stomach cancer (SC, n = 13), renal cell carcinoma (RCC, n = 19), and breast cancer (BC, n = 16) by dissociation of tumor tissue with collagenase/hyaluronidase. We investigated populations of naïve, effector, and memory T and TRM cells by flow cytometry. RESULTS: Among CD8- cells, CC was associated with a significantly higher proportion of CD103+ T cells than other tumor types (p < 0.001). Among CD8+ cells, CC and SC were associated with higher CD103+ T-cell proportions than RCC and BC (p < 0.001). Significantly more CD8+ than CD8- cells expressed CD103 (p < 0.001). In association with SC, RCC, and BC, CD8+ T cells had a similar T-cell phenotype composition pattern: fewer effector T cells and more memory-type T cells among CD103+ cells compared with CD103- cells (p < 0.05). Tumors with higher proportion of CD103+ cells had no specific clinicopathologic characteristics than those with lower proportion of CD103+ cells. CONCLUSION: TRM cell abundance and phenotypes varied among CC, SC, RCC, and BC. Further studies regarding the functional differences of TRM associated with various tumors are warranted.

A New Human Leukocyte Antigen Typing Algorithm Combined With Currently Available Genotyping Tools Based on Next-Generation Sequencing Data and Guidelines to Select the Most Likely Human Leukocyte Antigen Genotype.

Background: High-precision human leukocyte antigen (HLA) genotyping is crucial for anti-cancer immunotherapy, but existing tools predicting HLA genotypes using next-generation sequencing (NGS) data are insufficiently accurate. Materials and Methods: We compared availability, accuracy, correction score, and complementary ratio of eight HLA genotyping tools (OptiType, HLA-HD, PHLAT, seq2HLA, arcasHLA, HLAscan, HLA*LA, and Kourami) using 1,005 cases from the 1000 Genomes Project data. We created a new HLA-genotyping algorithm combining tools based on the precision and the accuracy of tools' combinations. Then, we assessed the new algorithm's performance in 39 in-house samples with normal whole-exome sequencing (WES) data and polymerase chain reaction-sequencing-based typing (PCR-SBT) results. Results: Regardless of the type of tool, the calls presented by more than six tools concordantly showed high accuracy and precision. The accuracy of the group with at least six concordant calls was 100% (97/97) in HLA-A, 98.2% (112/114) in HLA-B, 97.3% (142/146) in HLA-C. The precision of the group with at least six concordant calls was over 98% in HLA-ABC. We additionally calculated the accuracy of the combination tools considering the complementary ratio of each tool and the accuracy of each tool, and the accuracy was over 98% in all groups with six or more concordant calls. We created a new algorithm that matches the above results. It was to select the HLA type if more than six out of eight tools presented a matched type. Otherwise, determine the HLA type experimentally through PCR-SBT. When we applied the new algorithm to 39 in-house cases, there were more than six matching calls in all HLA-A, B, and C, and the accuracy of these concordant calls was 100%. Conclusions: HLA genotyping accuracy using NGS data could be increased by combining the current HLA genotyping tools. This new algorithm could also be useful for preliminary screening to decide whether to perform an additional PCR-based experimental method instead of using tools with NGS data.

Synthesis, Biological Evaluation, and Computational Analysis of Biaryl Side-Chain Analogs of Solithromycin.

There is an urgent need for new antibiotics to mitigate the existential threat posed by antibiotic resistance. Within the ketolide class, solithromycin has emerged as one of the most promising candidates for further development. Crystallographic studies of bacterial ribosomes and ribosomal subunits complexed with solithromycin have shed light on the nature of molecular interactions (π-stacking and H-bonding) between from the biaryl side-chain of the drug and key residues in the 50S ribosomal subunit. We have designed and synthesized a library of solithromycin analogs to study their structure-activity relationships (SAR) in tandem with new computational studies. The biological activity of each analog was evaluated in terms of ribosomal affinity (Kd determined by fluorescence polarization), as well as minimum inhibitory concentration assays (MICs). Density functional theory (DFT) studies of a simple binding site model identify key H-bonding interactions that modulate the potency of solithromycin analogs.

Pleuropulmonary Blastoma with Hotspot Mutations in RNase IIIb Domain of DICER 1: Clinicopathologic Study of 10 Cases in a Single-Institute Experience.

INTRODUCTION: Pleuropulmonary blastoma (PPB) is a rare sarcomatous malignancy involving the lung and pleura which occurs in early childhood. Cystic PPB in the early stage can be misdiagnosed as other cystic diseases. Early detection of this entity is important for appropriate treatment and prevention of disease progression. Hotspot mutations in the ribonuclease IIIb (RNase IIIb) domain of DICER1 have been reported to have a crucial role as genetic factors of PPB and DICER1 familial syndrome. We reviewed the clinicopathologic findings of PPB and the status of DICER1 hotspot mutation and patients' clinical course. METHODS: We retrospectively reviewed all patients with histologically confirmed PPB at Asan Medical Center between 2000 and 2017. Ten cases were identified in the database, and their clinicopathologic parameters were evaluated. PPB was classified into the following 3 pathologic subtypes: type I (purely cystic), type II (mixed cystic and solid), and type III (entirely solid). The status of DICER1 mutation in 2 hotspot regions of the RNase IIIb domain was evaluated by Sanger sequencing. RESULTS: The most frequent PPB type was II (6 cases), followed by I and III (2 cases each). The age at diagnosis ranged from 16 months to 15 years. All patients underwent surgery, and all patients received adjuvant or neoadjuvant chemotherapy. Four of 7 patients had missense mutations in the RNase IIIb hotspot; the base and predicted corresponding amino acid changes were c.5113 G>A (p.E1705K), c.5407 G>A (p.E1803K), c.5425 G>A (p.G1809R), and c.5428 G>T (p.D1810Y). There was no particular association between the presence of the hotspot mutation and histologic type. Nine patients survived with no evidence of disease for a median interval of 93 (range, 13-199) months. Only 1 patient diagnosed with type III PPB at the age of 18 years had recurrence after 20.8 months and eventually died 66 months after the initial diagnosis. CONCLUSIONS: Late detection of solid PPB is associated with poor prognosis. Considering the rarity of PPB disease and the importance of DICER1 hotspot mutation in pathogenesis, DICER1 hotspot mutation testing and identification in the early cystic stage can improve patient outcomes.