No abstract

Single EBUS-TBNA passes yield DNA of high quantity and quality with high accuracy for molecular profiling, irrespective of tumor cell content.

Malignant pleural effusion (MPE) may be diagnosed by cytologic evaluation of pleural fluid, though false negative results can occur. Pleural effusions may provide a source of tumour material for genotyping in lung cancer patients. Detection of MPE may be improved through use of highly sensitive molecular techniques. We identified five patients with non-small cell lung cancer (NSCLC) with initial pleural fluid samples that were non-malignant on cytology, but were subsequently clinically confirmed to have MPE. Tumour mutation status was confirmed via routine testing of diagnostic clinical specimens. Cytologically negative pleural fluid cell-block specimens were analysed by amplicon-based parallel sequencing (APS) for somatic mutations commonly detected in NSCLC, and selected cases by improved and complete enrichment CO-amplification at lower denaturation temperature PCR (ICECOLD PCR) for known mutations. Mutations were detected in three out of three (sensitivity 100%) cytologically non-malignant pleural fluids from patients with a known mutation: two patients with known Kirsten rat sarcoma (KRAS) mutation demonstrated the same KRAS mutation in their pleural fluids by APS, both at approximately 2% mutant allele frequency. In one patient with a known KRAS mutation, ICECOLD PCR detected the same KRAS variant at 0.7% frequency. No mutations were detected in patients with wild-type findings from reference samples (specificity 100%). Sensitive DNA sequencing methods can detect cancerdriver mutations in cytologically non-malignant pleural fluid specimens from NSCLC patients with MPE. Our findings demonstrate the feasibility of sensitive molecular diagnostic techniques for improvement of diagnostic assessment of pleural effusions in patients with lung cancer.

Objectives To investigate the utility of Magnetic Resonance Imaging (MRI) for prostate cancer diagnosis in the Australian setting. Patients and methods All consecutive men who underwent a prostate biopsy (transperineal or transrectal) at Royal Melbourne Hospital between July 2017 to June 2019 were included, totalling 332 patients. Data were retrospectively collected from patient records. For each individual patient, the risk of prostate cancer diagnosis at biopsy based on clinical findings was determined using the European Randomized study of Screening for Prostate Cancer (ERSPC) risk calculator, with and without incorporation of MRI findings. Results MRI has good diagnostic accuracy for clinically significant prostate cancer. A PI‐RADS 2 or lower finding has a negative predictive value of 96% for clinically significant cancer, and a PI‐RADS 3, 4 or 5 MRI scan has a sensitivity of 93%. However, MRI has a false negative rate of 6.5% overall for clinically significant prostate cancers. Pre‐ biopsy MRI may reduce the number of unnecessary biopsies, as up to 50.0% of negative or ISUP1 biopsies have MRI PI‐RADS 2 or lower. Incorporation of MRI findings into the ERSPC calculator improved predictive performance for all prostate cancer diagnoses (AUC 0.77 vs 0.71, P = .04), but not for clinically significant cancer (AUC 0.89 vs 0.87, P = .37). Conclusion MRI has good sensitivity and negative predictive value for clinically significant prostate cancers. It is useful as a pre‐biopsy tool and can be used to significantly reduce the number of unnecessary prostate biopsies. However, MRI does not significantly improve risk predictions for clinically significant cancers when incorporated into the ERSPC risk calculator.

No abstract

Activating mutations in and genes in patients with colorectal cancer (CRC) are associated with a lack of response to treatment with anti-epidermal growth factor receptor (EGFR) therapies. Mutations in these genes are thought to be mutually exclusive, however reports have described CRCs with two activating rat sarcoma (RAS) mutations. This has fuelled discussion about whether these mutations are the result of intratumorous heterogeneity, or if they are co-occurring in the same cancer cell clone. We present a case of a colorectal tumour with three RAS mutations detected during routine diagnostic testing. Further detailed analysis with laser capture microdissection and next generation sequencing excluded the possibility of all three mutations being present in the same clone, presenting the highest resolution evidence of intratumorous heterogeneity of RAS mutations to date.

Neurocysticercosis (NCC) is a disease caused by infection of the central nervous system with the larval stage of the tapeworm Taenia solium. This disease is endemic in many parts of the world, including Africa, Asia, and Latin America, where animal husbandry practices are common such that pigs reared for human consumption ingest feces from humans infected with T. solium. Neurocysticercosis is rarely acquired in economically affluent regions, including North America, Central Europe, Japan, and Australasia, and in countries where pork consumption is discouraged by religious or social practices. In these countries, NCC is usually diagnosed in immigrants or returning travelers who have spent time in endemic regions. Here, we report a case of NCC in a 25-year-old woman presenting with worsening visual symptoms in association with headache, diagnosed previously as a migraine with visual aura. This person had always lived in Australia and had never traveled overseas to a country endemic for T. solium. The unusual features of the clinical presentation and epidemiology are highlighted to raise physicians' awareness that attention needs to be paid to the risk of autochthonous infection occurring in non-endemic countries.

Case presentation: A 64-year-old man presented with a one week history of firm right parotid swelling. Computed tomography (CT) and magnetic resonance imaging (MRI) confirmed a right parotid mass with possible infiltration into preauricular soft tissue and the zygomatic arch. The patient proceeded to a radical right parotidectomy with segmental resection of temporal bone. Histology revealed an infiltrative tumour arising from the parotid comprising cystic spaces and cribriform glands lined predominantly by oncocytes with few mucocytes. Tumour cells showed diffuse staining with p63 and mucocytes stained with PAS and Alcian blue. A diagnosis of oncocytic variant of mucoepidermoid carcinoma (MEC) was made. Discussion: Oncocytic mucoepidermoid carcinoma (OMEC) is a rare variant of MEC composed chiefly of oncocytic cells. Recognition of this variant is important due to the histologic overlap with other oncocytic salivary gland tumours including benign entities, thus correct diagnosis is essential for appropriate treatment. The presence of typical MEC features such as mucocytes along with diffuse staining of p63 and detection of MAML2 rearrangements helps distinguish OMEC from its mimics. While few cases have been described, OMEC appears to have a favourable prognosis with a low local recurrence rate and minimal propensity for metastasis.