Pathology最新文献

Acral melanoma (AM) is the most common subtype of melanoma in the Asian population. Abnormalities in the p16-cyclin D1-CDK4 signalling pathway play a crucial role in the development and progression of AM. However, the CDK4 copy number variations (CNVs) in AM are under-reported. In this study, we investigated CDK4 gene copy number and concurrent molecular changes in a Chinese cohort with AM, to explore CDK4 CNVs and their significance in AM. We examined CDK4 CNVs with fluorescence in situ hybridisation (FISH) in 31 patients with AM. Six patients with CDK4 high-level copy number increase were examined by next-generation sequencing to detect concurrent molecular changes. Using FISH, 12 (12/31, 38.7%) cases showed CDK4 copy number increase, with six (6/31, 19.4%) low-level copy number increase and six (6/31, 19.4%) high-level copy number increase. Five of six CDK4 low-level copy number increase cases were accompanied by polysomy of chromosome 12, while one case was not. Two of six CDK4 high-level copy number increase cases were accompanied by polysomy of chromosome 12, while four cases were not. CDK4 copy number increase was significantly correlated with younger patient age. In six CDK4 high-level copy number increase cases, one case was found to be accompanied by NRAS mutation, one case was accompanied by HER2 mutation, one case was accompanied by BCL2L11 mutation ​and one case was accompanied by BRAF, HER2 and BCL2L11 mutations. Our study confirmed the presence of CDK4 copy number increase in AM cases. Detecting CDK4 copy number increase by FISH can be reliable in the diagnosis of AM. Some CDK4 copy number increases are the results of polysomy of chromosome 12. CDK4 high-level copy number increase coexists with other pathogenic mutations in AM. CDK4 appears to be a promising target for AM treatment and is expected to be combined with other targeted therapies.

This study evaluated the performance of a customised Sensititre YeastOne (SYO) plate including isavuconazole (YIT) against existing practice (comprising SYO YO10 plate and isavuconazole gradient strip) in order to streamline the workflow for antifungal susceptibility testing in a tertiary hospital in Singapore. A total of 101 (51 yeasts and 50 moulds) clinical isolates were included for analysis. Isolates included in the study were recovered from a variety of body sites and reflected the case mix encountered in daily practice. Antifungal susceptibility testing was performed using three methods: YO10, YIT and gradient diffusion strip (for isavuconazole only). Reproducibility, essential agreement (EA) and categorical agreement (CA) were calculated. When YO10 and YIT plates were compared, the reproducibility was 100% for eight common antifungals. The CA was >97% for all antifungals except for amphotericin B (89.4%), but this was attributed to seven isolates with minimum inhibitory concentrations bordering the wild-type (WT) cut-off. The EA obtained when testing isavuconazole using YIT versus gradient diffusion was 77.2% overall, 90.2% for yeasts and 64% for moulds. In conclusion, the YIT plate is suitable for antifungal susceptibility testing of yeasts in our laboratory. Its use for mould isolates needs to be monitored further.

It remains to be determined if the prognostic value of cribriform morphology (Crib) associated with intraductal carcinoma of the prostate (IDC) is equivalent to that in conventional/acinar prostatic adenocarcinoma (CPA). We herein assessed radical prostatectomy findings and long-term oncologic outcomes in 732 men with Grade Group 2-4 CPA without any Gleason pattern 5. Our cases were divided into four cohorts according to the absence or presence of Crib within CPA and/or IDC: Cohort-1, no Crib (n=347; 47.4%); Cohort-2, Crib only in CPA (n=203; 27.7%); Cohort-3, Crib only in IDC (n=17; 2.3%); and Cohort-4, Crib in both CPA and IDC (n=165; 22.5%). Compared with that in CPA only (Cohort-2), Crib in both CPA and IDC (Cohort-4) was significantly associated with adverse histopathological features, including higher tumour grade/stage and larger tumour volume. Univariate analysis revealed significantly higher risks of postoperative recurrence in patients with Crib in IDC only [Cohort-3; hazard ratio (HR) 2.450, p=0.022] or both CPA and IDC (Cohort-4; HR 2.835, p<0.001) than in those with Crib in CPA only (Cohort-2), whereas the prognosis was analogous between Cohort-3 and Cohort-4 (p=0.913). In a multivariable analysis [Crib in CPA only (Cohort-2) as a reference], Crib in IDC only (Cohort-3; HR 3.821, p=0.002) or both CPA and IDC (Cohort-4; HR 1.905, p=0.004) showed significantly worse recurrence-free survival. Compared with Crib in CPA only, its presence in both CPA and IDC was thus found to be independently associated with a poorer prognosis, suggesting a potentially greater clinical impact of Crib in IDC than in CPA.

Collecting urine samples in neonates by catheterisation or suprapubic puncture causes trauma, whereas self-adhesive collection bags can damage fragile skin. An alternative method is the collection of samples from urine-soaked cotton wool balls placed in diapers. The aim of this study was to compare the concentration of albumin, creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and uromodulin between clean-catch urine and samples collected in cotton wool balls in neonates and assess the efficiency of exosome extraction. Standard clean-catch urine samples were assayed for albumin, creatinine, NGAL, and uromodulin using commercial enzyme-linked immunosorbent assay (ELISA) kits. Concentrations were compared to the same urine samples extracted immediately from soaked cotton wool balls (sample 2, S2) or the urine extracted from cotton wool balls placed in a diaper in a warm incubator for 2 h before extraction (sample 3, S3). Exosomes were extracted from all three samples of one patient for visualisation by electron microscopy. Twenty-six infants (17 males) of median gestational age at birth of 32+1 weeks had urine collected at a median age of 29 days at 37+6 weeks corrected age. Concentrations in S2 and S3 were within 10% of the concentration of standard samples in 46% and 35% of specimens for albumin, 69% and 58% for creatinine, 12% and 12% for NGAL, and 27% and 15% for uromodulin, respectively, without consistent positive or negative bias. Urine albumin/creatinine ratios (UACRs) were 4.3% less in S2 and 4.5% less in S3 than in standard samples. Exosomes were extracted and visualised from all three sample types. Neonatal urine samples extracted from cotton wool balls can be used to screen for relevant albuminuria ​but provide imprecise estimates of NGAL and uromodulin. The proof of exosome extraction from urine collection in cotton wool balls opens the potential to examine exosomal cargo.

Shigellosis is an acute, often dysenteric, diarrhoeal illness that is responsible for much morbidity and mortality worldwide. Increasing rates of multidrug-resistant (MDR) and extensively drug-resistant (XDR) ​Shigella species have been detected worldwide and a regular review of local epidemiological and resistance rates is necessary to help guide empirical antibiotic choice. This retrospective laboratory study of faecal isolates between 2013 and 2023 demonstrates increasing rates of resistance to third-generation cephalosporins, azithromycin and ciprofloxacin, alongside an overall increase in MDR and XDR isolates.

Large nested melanomas (LNMs) are a rare subtype of naevoid melanoma consisting of large junctional melanocytic nests that are more common in older individuals and/or associated with sun damage. However, the presence of large melanocytic nests alone does not lead to a diagnosis of malignancy, ​as they can also be found in melanocytic naevi. LNMs are challenging because they lack most classic histological features of malignancy and require thorough clinicopathological evaluation. This ambiguity calls for a critical reassessment of the current diagnostic criteria for the subclassification of benign or malignant within the spectrum of large nested melanocytic tumours (LNMTs). Eighteen LNMTs and six special-site melanocytic naevi (SSMNs) ​were studied using different approaches: clinical features, dermoscopy, histopathology, immunohistochemistry, array comparative genomic hybridisation (aCGH) and messenger RNA (mRNA) sequencing analysis, with the aim of identifying novel and reproducible criteria for the recognition of LNMs.Careful clinicopathological evaluation of the 18 LNMTs led to the diagnosis of seven LNMs and 11 large nested melanocytic naevi (LNMNs). Lentiginous spread and nest bridging were significantly associated with LNMs after Holm-Bonferroni correction. Asymmetry, largest nest size, poor lateral demarcation, the number of colours and dermoscopic structures, and preferentially expressed antigen in melanoma (PRAME) immunostaining were more common in LNMs but did not reach statistical significance. Four of seven LNMs and nine of 11 LNMNs lacked the BRAF V600E mutation. Regarding aCGH, no LNMN or SSMN cases had ≥3 copy number variations (CNVs), in contrast to 50% of LNM cases. Importantly, LNM and LNMN could be distinguished by differential mRNA expression of nine genes. Our study demonstrates that there is a spectrum of LNMTs and that the clinicopathological diagnosis of LNM, for which we support the term 'late-onset nested naevoid melanomas', can be significantly strengthened by the presence of lentiginous pattern, nest bridging, gene CNV and differential mRNA expression.