Computer-assisted assessment of the Human Epidermal Growth Factor Receptor 2 immunohistochemical assay in imaged histologic sections using a membrane isolation algorithm and quantitative analysis of positive controls

<p>Abstract</p> <p>Background</p> <p>Breast cancers that overexpress the human epidermal growth factor receptor 2 (HER2) are eligible for effective biologically targeted therapies, such as trastuzumab. However, accurately determining HER2 overexpression, especially in immunohistochemically equivocal cases, remains a challenge. Manual analysis of HER2 expression is dependent on the assessment of membrane staining as well as comparisons with positive controls. In spite of the strides that have been made to standardize the assessment process, intra- and inter-observer discrepancies in scoring is not uncommon. In this manuscript we describe a pathologist assisted, computer-based continuous scoring approach for increasing the precision and reproducibility of assessing imaged breast tissue specimens.</p> <p>Methods</p> <p>Computer-assisted analysis on HER2 IHC is compared with manual scoring and fluorescence in situ hybridization results on a test set of 99 digitally imaged breast cancer cases enriched with equivocally scored (2+) cases. Image features are generated based on the staining profile of the positive control tissue and pixels delineated by a newly developed Membrane Isolation Algorithm. Evaluation of results was performed using Receiver Operator Characteristic (ROC) analysis.</p> <p>Results</p> <p>A computer-aided diagnostic approach has been developed using a membrane isolation algorithm and quantitative use of positive immunostaining controls. By incorporating internal positive controls into feature analysis a greater Area Under the Curve (AUC) in ROC analysis was achieved than feature analysis without positive controls. Evaluation of HER2 immunostaining that utilized membrane pixels, controls, and percent area stained showed significantly greater AUC than manual scoring, and significantly less false positive rate when used to evaluate immunohistochemically equivocal cases.</p> <p>Conclusion</p> <p>It has been shown that by incorporating both a membrane isolation algorithm and analysis of known positive controls a computer-assisted diagnostic algorithm was developed that can reproducibly score HER2 status in IHC stained clinical breast cancer specimens. For equivocal scoring cases, this approach performed better than standard manual evaluation as assessed by ROC analysis in our test samples. Finally, there exists potential for utilizing image-analysis techniques for improving HER2 scoring at the immunohistochemically equivocal range.</p

Encephalitis associated with a monoclonal protein band present in blood, urine and cerebrospinal fluid

Introduction: Monoclonal protein bands are present mainly in blood and secondary in urine representing specific antibody produced in excess by abnormal lymphocytes or plasma cells.We describe a case of a patient with acute encephalitis associated with an unexpected finding of a monoclonal protein band present in blood, urine and in cerebrospinal fluid (CSF). Case presentation: This 50-year-old woman with no significant past medical history, with the exception of unintentional weight loss exceeding 5 kg over the last 3 months, presented to the emergency department with seizures and altered mental status, after 3 days of vomiting and headaches. Magnetic Resonance Imaging showed lesions suspicious for infectious encephalitis/meningitis and for ischemia possibly related to central nervous system (CNS) autoimmune vasculopathy/vasculitis. The patient died the following day after losing brainstem reflexes. Testing for the previously mentioned etiologies returned negative with the exception of high protein concentration and increased immunoglobulin gamma (IgG) concentration in the CSF. Protein electrophoresis, ordered in error, showed a well-defined IgG with lambda light chain monoclonal protein band running in similar positions in serum, urine and in CSF. Due to SARS-CoV-2 PCR positivity no autopsy was performed. Conclusion: The presence of this monoclonal protein band produced in the CNS suggests the diagnosis of CNS myeloma. The accelerated course in this case could be the result of the CNS myeloma or lymphoma responding to SARS-CoV-2 infection. Testing for monoclonal protein bands in CSF, in patients with pertinent clinical presentation would boost the awareness of this these diseases improving patient care