Conventional G-banded karyotype is an essential tool for detecting chromosomal variants in patients undergoing fertility evaluation. In Australia, 15 cells are traditionally analysed or counted, to enhance detection of mosaic chromosomal variants. However, this protocol is not backed by clinical evidence. This study aims to assess the test performance of an abbreviated 5-cell karyotype analysis protocol in adult patients undergoing fertility evaluation.
A retrospective review of 53,293 blood karyotype tests, performed between 2019 and 2023, was conducted on a patient cohort primarily referred by reproductive endocrinology specialists. There were 513 variants reported in this cohort. Low level mosaic variants, where the variant was observed in less than 40% of cells, were reported in 13 cases, or one in 4,100 patients. Due to reduced sensitivity for low level mosaic variants, a 5-cell protocol is estimated to have a test sensitivity of 97.3% and a negative predictive value of 99.97%. A decision-making flowchart is proposed and we show that additional chromosome analysis and/or counts would be triggered in fewer than one in 10 cases using a 5-cell protocol, whilst remaining appropriate for detecting clinically significant mosaicism.
A 5-cell karyotype analysis protocol therefore maintains analytical and clinical validity in adult patients undergoing fertility-related blood karyotyping. Future research is recommended to validate these findings across laboratories and to explore their application to other clinical contexts.
Measurable residual disease (MRD) is useful for prognostication and for monitoring response to treatment in patients with acute leukaemia. MRD by multiparametric flow cytometry (MFC-MRD) utilises the leukaemia-associated immunophenotype (LAIP) and difference from normal (DfN) strategies to identify the leukaemic clone. Difficulties arise when the LAIP overlaps with normal regeneration, there is clonal evolution, or when the abnormal clone population is exceptionally small e.g., <0.01% of CD45+ cells. Such cases are reported as ‘indeterminate’; however, there is little international consensus on this reporting. The relationship between clinical outcomes and indeterminate MFC-MRD is unknown. Here we determine the rate of indeterminate MFC-MRD reporting, its relationship to concurrent molecular MRD results when available, and to clinical outcomes to 12 months. We performed an internal audit of all adult testing for MFC-MRD between January and December 2021. A total of 153 consecutive patients with a diagnosis of acute leukaemia were included. Successive MFC-MRD results and clinical outcomes were recorded over a 12-month period from time of inclusion into the study. In total, 460 MFC-MRD tests from 153 patients were reviewed and 73 (16%) MFC-MRD tests from 54 (35%) patients were reported as indeterminate. The majority (70%) were at low levels between 0.01–0.1% of CD45+ cells. Compared to patients with a negative result, acute myeloid leukaemia (AML) was more frequent in patients who had an indeterminate MFC-MRD (70% vs 36%), and B-cell acute lymphoblastic leukaemia was less common (20% vs 55%). In patients with indeterminate MFC-MRD results, one-third had received either chemotherapy or allogeneic haemopoietic stem cell transplant (aHSCT) within the preceding 3 months. Agreement between MFC and molecular MRD testing was low. Patients with indeterminate MFC-MRD had leukaemia relapse rates below patients with a positive MFC-MRD, but greater than those with negative MFC-MRD (positive 33% vs indeterminate 21% vs negative 8%, p = 0.038). Overall, these findings indicate that indeterminate MFC-MRD results are more common in adults with AML and also in those who have received chemotherapy or aHSCT within the previous 3 months. We report for the first time that indeterminate MFC-MRD is a finding of potential clinical significance, which associates with a numerically higher median relapse rate within 12 months when compared to a negative MFC-MRD result.
Hidrocystoma is thought to be a benign retention cyst of sweat ductal units. The lesion is usually located in the periorbital skin; however, lesions with similar histopathological features are rarely observed in extra-facial sites. Herein, we present four cases of hidrocystoma-like tumours in extra-facial skin sites that harboured a RET or ALK rearrangement. This study features a 67-year-old female with a 10 mm-sized digital tumour (Case 1), a 62-year-old male with an 8 mm-sized clavicular tumour (Case 2), a 61-year-old male with a 19 mm-sized digital tumour (Case 3), and an 11-year-old female with a 10 mm-size lower leg tumour (Case 4) as well as five control cases (Cases 5–9) of classical periorbital hidrocystoma. In Cases 1–4, multicystic tumours comprising a two-cell layer of inner cuboidal ductoglandular (p63− and SOX10+/−) and outer flat myoepithelial (p63+ and SOX10+) cells were observed. The inner ductoglandular tumour cells exhibited micropapillary projections and Roman bridging structures. No apparent atypical cells were observed. NCOA4::RET in Cases 1 and 3, CCDC6::RET in Case 2, and SLC12A2::ALK in Case 4 were revealed by next-generation sequencing or Sanger sequencing. In contrast, control cases of classical hidrocystoma (Cases 5–9) did not show intracystic proliferation, abundant cytoplasm, ALK immunoreactivity, or NCOA4::RET detection in the tumour cells. RET/ALK-rearranged hidrocystoma-like tumours are tumour entities that can be distinguished from classical hidrocystoma. This RET/ALK-rearranged neoplasm is benign and is frequently observed in the digits. Future studies will establish the concept, detailed clinicopathological characteristics, and genetic variations of hidrocystoma-like tumours.
The colon is the most common site for endometriosis outside the genital tract. It has a varied presentation and can mimic numerous other conditions, both clinically and pathologically. We investigated the clinicopathological features of a series of colorectal endometriosis with a particular emphasis on the features seen in cases with colonic mucosal involvement. A total of 114 consecutive cases of colorectal endometriosis were reviewed. Forty-eight percent did not have a prior diagnosis of endometriosis and in 34 patients (30%) the endometriosis was determined as the cause for the presentation. Mucosal involvement was present in 31 specimens. Features of chronic colitis were seen in the adjacent mucosa in 90% of cases whilst there were glandular changes mimicking adenocarcinoma in two cases (1.8%). Fifty percent of cases with mucosal involvement also showed glands with a hybrid intestinal-endometrial phenotype by morphology and/or by immunohistochemistry. Endometriosis is an important mimic of other conditions.
Infections caused by vancomycin-resistant enterococci (VRE) are common. Real-time PCR assays targeting vanA and vanB facilitate screening of patients in healthcare settings to limit the risk of dissemination, especially amongst those at high-risk of infection or with limited treatment options. Such assays are commonly performed as reflex testing procedures where they augment phenotypic techniques and shorten turnaround time to benefit timely clinical management. ‘Random access’ and ‘sample-to-result’ real-time PCR platforms are suited for this application as they are of low complexity and less technically demanding. Modelled on these attributes, we configured a real-time PCR assay (VRE BD) for detection of vanA/B in clinical isolates of enterococci, adapted for the BD Max System (Becton Dickinson). We applied an unconventional approach by testing suspensions of microorganisms in water to circumvent the traditional pre-analytical genomic extraction process. Our objective of this study was to assess the performance of this assay for detection of VRE in cultures by validating against a traditional real-time PCR assay based on the LightCycler 2.0 platform (Roche, VRE RO). A high level of analytical sensitivity and specificity (≥99.0%) for both genes was obtained when testing suspensions derived from blood agar. Results for suspensions obtained from chromID VRE (Edwards Group) showed a similar level of performance for vanA detection (100%), but not for the vanB target (≥90.9%) where a lesser number of isolates were available for testing. However, our results for VRE detection in isolates from these media were repeatable and reproducible, and equated to positive and negative predictive values of ≥95.2% and ≥97.8%, respectively. Furthermore, the VRE BD assay was also able to accurately detect VRE in clinical and spiked BacT/ALERT (bioMérieux) blood cultures. Thus, the technical simplicity, short turnaround time and robustness of this high performing assay for VRE is suitable for reflex testing. In addition, the format developed for the BD Max platform has potential application for reflex testing other molecular targets of clinical importance.