Diagnostic Adjunct Research Articles

Mechanically Disaggregated Unfixed Trephine Biopsies Can be Used for Diagnostic Immunophenotyping in Acute Leukaemia

An adequate bone marrow sample is essential for a rapid diagnosis of acute leukaemia by multicolour flow cytometry enabling the assignment of lineage and choice of therapy.Diagnosis is sometimes delayed due to difficulties in of obtaining a bone marrow aspirate due to a ‘dry tap’.In this study we evaluated immunophenotyping of mechanically disaggregated unfixed bone marrow trephine biopsies from 62 paediatric and adult patients at diagnosis (mostly acute leukemia). We compared the results to immunophenotyping of blood and aspirate samples and the trephine biopsy histology.In 26 of 62 cases no disease was present in the blood and the aspirate was a ‘dry tap’. In 24 of 26 cases a diagnosis was reached by immunophenotyping from the disaggregated bone marrow biopsy. Results were concordant with histopathology in all 24 cases (22 acute lymphoblastic leukemia(ALL) cases, 2 acute myeloid leukemia (AML) cases). In 2 cases insufficient cells were obtained from the disaggregated biopsy to reach a diagnosis.In 36 of 62 cases immunophenotyping was performed on disaggregated unfixed bone marrow trephine biopsies and compared to immunophenotyping on blood and/or aspirate as well as histology. The immunophenotyping findings were concordant in 33 cases between the (21 ALL, 6 AML, 3 myelodysplastic syndromes|(MDS), 3 other haematological malignancies). In 3 cases insufficient cells could be obtained from the disaggregated biopsy. In one of these the histology from the bone marrow biopsy showed cortical bone only, while the other two showed AML and MDS.In conclusion these data confirm earlier reports that immunophenotyping of mechanically disaggregated unfixed trephines is a useful diagnostic adjunct particularly where a dry tap has occurred. DisclosuresNo relevant conflicts of interest to declare.

Identification of Molecular Alterations Challenging Initial Pathologic Classification in Cases of Clinician-Initiated Next-Generation Sequencing Testing.

Large gene panel next-generation sequencing (NGS) is a powerful tool capable of generating predictive data on cancer prognosis and response to specific therapeutic interventions. The utility of large panel NGS data on tumor classification, however, may be underappreciated because of a workflow that often circumvents the surgical pathologist. We sought to describe cases in which NGS data lead to an unanticipated change in tumor classification and to discuss current workflow practices of NGS testing that limit its use as a diagnostic adjunct. We performed a retrospective review to identify cases in which NGS testing uncovered data that led to a revision of the initial pathologic diagnosis that an outside or in-house pathologist had made. Nine cases are presented in which NGS data provided insights that led to a revision of the original pathologic diagnosis. Distinctive molecular signatures, mutational signatures, fusions, or identification of viral sequencing provided the critical evidence on which these tumors were reclassified. The current workflow of NGS testing should always include the surgical pathologist as an active partner to ensure that the molecular results are fully reflected in the final diagnosis. In some instances, active participation by the surgical pathologist may require amendment of previously issued pathology reports.

Diagnostic Performance of Conebeam CT Pixel Values in Active Fenestral Otosclerosis.

Quantitative bone densitometry on multidetector CT of the temporal bone is a diagnostic adjunct for otosclerosis in its active (spongiotic) phase, but translating this technique to conebeam CT is limited by the technical variability of conebeam CT pixel values. The purpose of this study was to evaluate the performance of internally calibrated conebeam CT pixel value measurements that can enable the determination of active fenestral otosclerosis (otospongiosis). This study included 37 ears in 22 patients with a clinical diagnosis of otospongiosis in those ears and 35 ears in 22 control patients without the diagnosis. Temporal bone conebeam CT was performed. ROIs were set anterior to the oval window, in the lateral semicircular canal bone island, and in a nearby aerated space. Mean conebeam CT pixel values in these regions determined the relative attenuation ratio of the area anterior to the oval window normalized to normal otic capsule bone and air. The relative attenuation ratio for cases of otospongiosis was significantly lower than that for controls (P < .001). Based on receiver operating characteristic analysis, the optimal cutoff relative attenuation ratio was 0.876, which had an accuracy of 97.2% for the diagnosis of otospongiosis. Internally calibrated pixel value ratios in temporal bone conebeam CT can feasibly help diagnose active/spongiotic-phase fenestral otosclerosis in an objective manner.

Evaluating Lumbar Intervertebral Disc Degeneration on a Compositional Level Using Chemical Exchange Saturation Transfer: Preliminary Results in Patients with Adolescent Idiopathic Scoliosis.

Lumbar intervertebral disc (IVD) degeneration is characterized by structural and compositional changes. This study aimed to assess the glycosaminoglycan (GAG) content of IVDs of patients with adolescent idiopathic scoliosis (AIS) and healthy controls using GAG chemical exchange saturation transfer (gagCEST) imaging. Ten AIS patients (mean age 18.3 ± 8.2 years) and 16 healthy controls (mean age 25.5 ± 1.7 years) were included. Clinical standard morphologic MR images (T1w-, T2w-, and STIR-sequences), to rule out further spinal disorders and assess IVD degeneration using the Pfirrmann score, and compositional gagCEST sequences were acquired on a 3T MRI. In AIS patients, the most distal scoliotic curve was determined on whole-spine conventional radiographs and morphological MRI and IVDs were divided as to whether they were affected by scoliotic deformity, i.e., proximal (affected, aIVDs) or distal (unaffected, uaIVDs) to the stable vertebra of the most distal scoliotic curve. Linear mixed models were used to compare mean gagCEST-values. Over all segments, AIS-patients’ IVDs exhibited significantly lower gagCEST-values than the controls: 2.76 [2.32, 3.20]% (AIS), 3.51 [3.16, 3.86]% (Control); p = 0.005. Meanwhile, no significant differences were found for gagCEST values comparing aIVDs with uaIVDs. In conclusion, as a powerful diagnostic adjunct, gagCEST imaging may be prospectively applied to detect early compositional degenerative changes in patients suffering from AIS.

A large retroperitoneal lipoblastoma as an incidental finding: a case report

BackgroundLipoblastoma is a rare benign mesenchymal neoplasm of infancy that most commonly occurs on the extremities and trunk but can arise at variable sites of the body. Retroperitoneal lipoblastomas are particularly rare but can grow to enormous size, and preoperative diagnosis is difficult with diverse, mostly malignant differential diagnoses that would lead to aggressive therapy. Since lipoblastoma is a benign tumor that has an excellent prognosis after resection, correct diagnosis is crucial.Case presentationA case of a large retroperitoneal tumor of a 24-month old infant that was clinically suspicious of a malignant tumor is presented. Due to proximity to the right kidney, clinically most probably a nephroblastoma or clear cell sarcoma of the kidney was suspected. Radiological findings were ambiguous. Therefore, the mass was biopsied, and histology revealed an adipocytic lesion. Although mostly composed of mature adipocytes, in view of the age of the patient, the differential diagnosis of a (maturing) lipoblastoma was raised, which was supported by molecular analysis demonstrating a HAS2-PLAG1 fusion. The tumor was completely resected, and further histopathological workup led to the final diagnosis of a 13 cm large retroperitoneal maturing lipoblastoma. The child recovered promptly from surgery and showed no evidence of recurrence so far.ConclusionAlthough rare, lipoblastoma should be included in the differential diagnoses of retroperitoneal tumors in infants and children, and molecular diagnostic approaches could be a helpful diagnostic adjunct in challenging cases.

Evaluation of Immunohistochemical Markers, CK17 and SOX2, as Adjuncts to p53 for the Diagnosis of Differentiated Vulvar Intraepithelial Neoplasia (dVIN).

Histological diagnosis of differentiated vulvar intraepithelial neoplasia (dVIN), the precursor of human papillomavirus (HPV)-independent vulvar squamous cell carcinoma (VSCC), can be challenging, as features of dVIN may mimic those of non-dysplastic dermatoses. To aid the diagnosis, p53-immunohistochemistry (IHC) is commonly used, and mutant expression patterns are used to support a histological diagnosis of dVIN. However, a proportion of dVIN can show wild-type p53-expression, which is characteristic of non-dysplastic dermatoses. Furthermore, recent research has identified a novel precursor of HPV-independent VSCC—the p53-wild-type differentiated exophytic vulvar intraepithelial lesion (de-VIL). Currently, there are no established diagnostic IHC-markers for p53-wild-type dVIN or de-VIL. We evaluated IHC-markers, cytokeratin 17 (CK17), and SRY-box 2 (SOX2), as diagnostic adjuncts for dVIN. For this, IHC-expression of CK17, SOX2, and p53 was studied in dVIN (n = 56), de-VIL (n = 8), and non-dysplastic vulvar tissues (n = 46). For CK17 and SOX2, the percentage of cells showing expression, and the intensity and distribution of expression were recorded. We also performed next generation targeted sequencing (NGTS) on a subset of dVIN (n = 8) and de-VIL (n = 8). With p53-IHC, 74% of dVIN showed mutant patterns and 26% showed wild-type expression. Median percentage of cells expressing CK17 or SOX2 was significantly higher in dVIN (p53-mutant or p53-wild-type) and de-VIL than in non-dysplastic tissues (p < 0.01). Diffuse, moderate-to-strong, full epithelial expression of CK17 or SOX2 was highly specific for dVIN and de-VIL. With NGTS, TP53 mutations were detected in both dVIN and de-VIL. We infer that immunohistochemical markers CK17 and SOX2, when used along with p53, may help support the histological diagnosis of dVIN.

Non-invasive Urinary Biomarkers in Moyamoya Disease.

Introduction: A major difficulty in treating moyamoya disease is the lack of effective methods to detect novel or progressive disease prior to the onset of disabling stroke. More importantly, a tool to better stratify operative candidates and quantify response to therapy could substantively complement existing methods. Here, we present proof-of-principle data supporting the use of urinary biomarkers as diagnostic adjuncts in pediatric moyamoya patients.Methods: Urine and cerebrospinal fluid specimens were collected from pediatric patients with moyamoya disease and a cohort of age and sex-matched control patients. Clinical and radiographic data were paired with measurements of a previously validated panel of angiogenic proteins quantified by ELISA. Results were compared to age and sex-matched controls and subjected to statistical analyses.Results: Evaluation of a specific panel of urinary and cerebrospinal fluid biomarkers by ELISA demonstrated significant elevations of angiogenic proteins in samples from moyamoya patients compared to matched controls. ROC curves for individual urinary biomarkers, including MMP-2, MMP-9, MMP-9/NGAL, and VEGF, showed excellent discrimination. The optimal urinary biomarker was MMP-2, providing a sensitivity of 88%, specificity of 100%, and overall accuracy of 91%. Biomarker levels changed in response to therapy and correlated with radiographic evidence of revascularization.Conclusions: We report, for the first time, identification of a panel of urinary biomarkers that predicts the presence of moyamoya disease. These biomarkers correlate with presence of disease and can be tracked from the central nervous system to urine. These data support the hypothesis that urinary proteins are useful predictors of the presence of moyamoya disease and may provide a basis for a novel, non-invasive method to identify new disease and monitor known patients following treatment.

Diagnostic efficacy of neutrophil to lymphocyte ratio (NLR) in oral potentially malignant disorders and oral cancer.

Inflammation is considered to be the seventh hallmark of cancer and plays a pivotal role in all stages of tumor development. Systemic inflammatory responses in particular neutrophil to lymphocyte ratio (NLR) have garnered immense attention of current researchers and its role is well proven in various solid malignancies. Its prognostic role in oral cancer have been extensively studied. However, its diagnostic role is yet to be explored. The current study aims to investigate diagnostic utility of NLR in oral potentially malignant disorders and oral cancer, when compared to normal subjects. A total of 150 subjects were involved in the study, a total of 2.5 ml of blood was drawn from the median cubital vein of the patient in an EDTA vial and hematological parameters were assessed using Erba-Transasia B7256 Autoanalyzer and reassessed manually by two experts. The NLR values were recorded and tabulated as Mean ± S.D. and comparisons were analyzed using Kruskal Wallis and Mann Whitney post hoc U test. ROC curve analysis was performed to estimate cut-off values. The NLR values when compared between the 3 groups were statistically significant (P < 0.001). The cut off value between disease and normal subject was 2.33, while the cut-off value between potentially malignant and malignant condition is 3.20. NLR can be a valuable diagnostic adjunct in oral cancer and potentially malignant disorders of oral cavity.

Localization of Brachial Plexopathies Using a Novel Diagnostic Program.

Background: Assessing the extent and specific location of brachial plexus injuries can be difficult given the variety of mechanisms of injury and anatomic complexity of the plexus. We developed a program to accurately assess the location of a patient's neurologic injury based on electromyographic data. Purpose: We sought to test our hypothesis that the location of traumatic brachial plexopathies could be accurately assessed with a novel program that processed electromyogram (EMG) and mechanism of injury data. Methods: This retrospective diagnostic cohort study was carried out with a novel diagnostic algorithm developed with the Python programming language. The program accepts user input of muscles demonstrating decreased motor unit recruitment, positive sharp waves, or fibrillation potentials. The testing data set was derived from a registry of brachial plexus injuries treated at our center. The primary outcome was the percent concordance of the algorithm's diagnosis with the surgical diagnosis. Results: Ninety-five cases met the inclusion criteria. Median time from injury onset to EMG examination was 4 months; median time from EMG examination to surgery was 1.2 months. The program diagnosis matched the surgical diagnosis in 92 out of 95 (97%) of cases, including cases with multilevel injuries and additional peripheral nerve injuries. Conclusion: This program accurately localized brachial plexopathies in nearly all cases, including those involving polytrauma or complex patterns of injury. This algorithm may be valuable as an aid to complete electrodiagnostic examinations, a diagnostic adjunct when planning treatment of severe plexus palsies, or an educational tool.

Role of inflammation in benign gynecologic disorders: from pathogenesis to novel therapies†.

Emerging evidence supports the notion that inflammation fosters the development of common benign gynecologic disorders, including uterine leiomyoma, endometriosis, and adenomyosis. Numerous cytokines, chemokines, and growth and transcription factors have indisputable roles in the establishment and maintenance of benign gynecologic disorders by initiating complex cascades that promote proliferation, angiogenesis, and lesion progression. The interaction between inflammation and benign gynecologic disorders is orchestrated by a plethora of factors, including sex steroids, genetics, epigenetics, extracellular matrix, stem cells, cardiometabolic risk factors, diet, vitamin D, and the immune system. The role of inflammation in these disorders is not limited to local pathobiology but also extends to involve clinical sequelae that range from those confined to the reproductive tract, such as infertility and gynecologic malignancies, to systemic complications such as cardiovascular disease. Enhanced understanding of the intricate mechanisms of this association will introduce us to unvisited pathophysiological perspectives and guide future diagnostic and therapeutic implications aimed at reducing the burden of these disorders. Utilization of inflammatory markers, microRNA, and molecular imaging as diagnostic adjuncts may be valuable, noninvasive techniques for prompt detection of benign gynecologic disorders. Further, use of novel as well as previously established therapeutics, such as immunomodulators, hormonal treatments, cardiometabolic medications, and cyclooxygenase-2 and NF-κB inhibitors, can target inflammatory pathways involved in their pathogenesis. In this comprehensive review, we aim to dissect the existing literature on the role of inflammation in benign gynecologic disorders, including the proposed underlying mechanisms and complex interactions, its contribution to clinical sequelae, and the clinical implications this role entails.

Blood-Based Detection of BRAF V600E in Gliomas and Brain Tumor Metastasis.

Simple SummaryThe BRAF V600E mutation has been identified as a key driver in brain tumors and brain tumor metastasis. The ability to detect this mutation in a minimally invasive plasma assay offers advantages over traditional tissue-based biopsy for the disease diagnosis and monitoring. The aim of this study was to develop an assay for the detection of BRAF V600E in the plasma of patients with brain tumors and brain tumor metastasis. We demonstrate BRAF V600E detection using a novel plasma-based ddPCR assay. We detect the mutation in circulating nucleic acids in 4/5 patients with mutant gliomas and metastatic melanoma. We also show correlation between plasma BRAF V600E and clinical status. This proof of principle study is important in the context of application of liquid biopsy in plasma to the neuro-oncologic field. The assay may be useful as a diagnostic adjunct, prognostication tool, and method for monitoring of disease and treatment response.Liquid biopsy provides a minimally invasive platform for the detection of tumor-derived information, including hotspot mutations, such as BRAF V600E. In this study, we provide evidence of the technical development of a ddPCR assay for the detection of BRAF V600E mutations in the plasma of patients with glioma or brain metastasis. In a small patient cohort (n = 9, n = 5 BRAF V600E, n = 4 BRAF WT, n = 4 healthy control), we were able to detect the BRAF V600E mutation in the plasma of 4/5 patients with BRAF V600E-tissue confirmed mutant tumors, and none of the BRAF WT tumors. We also provide evidence in two metastatic patients with longitudinal monitoring, where the plasma-based BRAF V600E mutation correlated with clinical disease status. This proof of principle study demonstrates the potential of this assay to serve as an adjunctive tool for the detection, monitoring, and molecular characterization of BRAF mutant gliomas and brain metastasis.

Introduction of nucleic acid amplification technology for blood screening in Hungary

Background &amp; AimsWith this study, we intended to report our experiences about introducing nucleic acid testing for blood donation screening for human immunodeficiency virus, hepatitis B and C in Hungary. This study summarizes the experiences of nucleic acid amplification technology (NAT) screening of the first 16 months.MethodsThe study was conducted from 5 June 2018 to 30 September 2019 in two phases. During the first 7 months of the study, the NAT tests were performed in parallel with serology. The yields of the methods were compared. After the initial seven months, only seronegative samples were tested by NAT. NAT tests were performed in minipools of 96.ResultsIn this 16‐month period, nearly 400 000 donations were screened by NAT. During the first phase, almost 150 000 samples were tested in parallel by serology and NAT screening. NAT screening during Phase I failed to identify 4 HCV‐ and 1 HBV‐reactive donations. In the second phase, about 245 000 seronegative samples were screened, with only one HBV reactive yield.ConclusionsNucleic acid amplification technology testing proven to be an optimal diagnostic adjunct to serological screening, since it can help to identify early window period infections and occult hepatitis B infections. According to our experience however, the used pooling strategy represents a dilution rate of nucleic acid targets, which makes identifying these types of infections difficult. According to our cost–benefit analysis, reducing the pool size to 60 would result in a 60% sensitivity increase, at the expense of increasing the daily costs by 25%.

Molecular Lymph Node Staging with One-Step Nucleic Acid Amplification and its Prognostic Value for Patients with Colon Cancer: The First Follow-up Study

BackgroundMolecular lymph node workup with one-step nucleic acid amplification (OSNA) is a validated diagnostic adjunct in breast cancer and also appealing for colon cancer (CC) staging. This study, for the first time, evaluates the prognostic value of OSNA in CC.Patients and methodsThe retrospective study includes patients with stage I-III CC from three centres. Lymph nodes were investigated with haematoxylin and eosin (H&E) and with OSNA, applying a 250 copies/μL threshold of CK19 mRNA. Diagnostic value of H&E and OSNA was assessed by survival analysis, sensitivity, specificity and time-dependent receiver operating characteristic curves.ResultsEighty-seven patients were included [mean follow-up 53.4 months (± 24.9)]. Disease recurrence occurred in 16.1% after 19.8 months (± 12.3). Staging with H&E independently predicted worse cancer-specific survival in multivariate analysis (HR = 10.77, 95% CI 1.07–108.7, p = 0.019) but not OSNA (HR = 3.08, 95% CI 0.26–36.07, p = 0.197). With cancer-specific death or recurrence as gold standard, H&E sensitivity was 46.7% (95% CI 21.3–73.4%) and specificity 84.7% (95% CI 74.3–92.1%). OSNA sensitivity and specificity were 60.0% (95% CI 32.3–83.7%) and 75.0% (95% CI 63.4–84.5%), respectively.ConclusionsIn patients with CC, OSNA does not add relevant prognostic value to conventional H&E contrasting findings in other cancers. Further studies should assess lower thresholds for OSNA (< 250 copies/μL).

Intranasal ketorolac, diagnosis, and desensitization for aspirin-exacerbated respiratory disease

BackgroundIntranasal ketorolac has been proposed as a diagnostic test for aspirin-exacerbated respiratory disease (AERD) and a faster, safer, and reliable addition to facilitating aspirin (ASA) desensitization. ObjectiveWe conducted the first prospective study to dissect the impact of intranasal ketorolac incorporation during ASA desensitization vs standard oral protocols in concert with evaluating its diagnostic use for AERD. MethodsPatients with AERD were enrolled in a prospective open-label observational study between November 2006 and August 2013. Participants selected either one of the following desensitization protocols: intranasal ketorolac 1 day before oral ASA (group 1, combined) or ketorolac challenge with greater than 2 weeks elapsing until oral ASA (group 2, washout). All patients were on a leukotriene-modifying drug (montelukast) for at least 1 week before the challenge. ResultsA total of 20 patients were enrolled: 13 in group 1 and 7 in group 2. No significant differences were seen for baseline symptom scores or forced expiratory volume in 1 second. Group 1 exhibited significant increases for the threshold dose of ASA (P = .009), the likelihood of having silent ASA desensitization (P = .01), and decreased reaction severity to oral ASA (P = .04). There were no significant differences in reaction forced expiratory volume in 1 second, the incidence of extrapulmonary symptoms, limited nasoocular reactions, rescue treatment requirements, or time to symptom resolution. There was 100% concordance between reactions to intranasal ketorolac and oral ASA for group 2, supporting its use as a diagnostic test for AERD. ConclusionIntranasal ketorolac is a useful diagnostic test and adjunct within the combined ketorolac/ASA protocol to achieve effective, efficient, and perhaps safer desensitization to ASA for patients with AERD.

Efficacy of oral brush cytology cell block immunocytochemistry in the diagnosis of oral leukoplakia and oral squamous cell carcinoma

This study assessed the efficacy of using oral liquid-based brush cytology and cell block immunocytochemistry in the diagnosis of oral leukoplakia as minimally invasive diagnostic adjuncts. Seventy-two patients diagnosed clinically with either oral leukoplakia (OLK) or oral squamous cell carcinoma were included. Oral brush samples using Orcellex® brushes were obtained from all participants directly before undergoing surgical biopsy. Cell blocks were prepared for all samples and assessed for cytomorphology and immunocytochemistry of DNA mismatch repair proteins (MSH-6, MSH-2, MLH-1 and PMS-2). A combined index score of immunocytochemistry expression and cytology grading was compared against the gold standard (histopathological diagnosis). A significant association was observed between the cytological assessments of oral liquid-based brush cytology samples and the histopathological diagnosis (P<.005). In addition, there was a significant inverse correlation between the grade of oral epithelial dysplasia and the cumulative score of the studied DNA mismatch repair proteins (P<.005). Grading criteria for both oral liquid-based brush cytology and immunocytochemistry cumulative index scores are proposed based on the analysis of receiver operating characteristic curve coordinates. The diagnostic accuracy of this approach was outstanding in terms of discrimination between the presence or absence of oral epithelial dysplasia (0.961) and squamous cell carcinoma (0.977) separately. Oral liquid-based brush cytology cell block immunocytochemistry provides a reliable strategy to investigate oral mucosal epithelial disorders. This approach presents a minimally invasive, highly accurate and non-technically demanding method for the surveillance of oral potentially malignant disorders and squamous cell carcinoma.

Orofacial Tuberculosis: An Uncommon Manifestation of A Common Disease- A Narrative Review

Tuberculosis is chronic multisystemic disease caused mostly by Mycobacterium tuberculosis. The diseasehas its mention in the Vedas and Chakra and Sushruta described the features in the early 600 B.C. TB hasa known site predilection for lungs, although, extra pulmonary cases have also been reported. The oraltuberculous lesions are a rare occurrence with atypical signs and symptoms, thus deferring an accuratediagnosis and treatment. A plethora of standard and contemporary diagnostic adjuncts facilitate the rapid andprecise diagnosis. Anti-tubercular regimen forms the mainstay of treatment, although several recent drugsare also in clinical trial phase.This article aims to highlight the etio-pathogenesis, clinical and oral features of tuberculosis, diagnostictools, and management protocol for tuberculosis. There is also a brief mention on the various policiesconsidered by World health Organization (WHO) to combat this dreaded disorder.

Can Hounsfield Unit Density Accurately Predict Recurrent Cholestatoma in Previously Operated Ears?

The objective of the study was to determine whether Hounsfield Unit density would differentiate between cholesteatoma and other causes of opacification, such as granulation tissue in previously operated ears. Temporal bone computer tomography (CT) scans of 47 patients, who had revision mastoid surgeries, were evaluated retrospectively. A circular 5 mm2 region of interest (ROI) was placed at aditus ad antrum to measure Hounsfield Unit (HU) density. There was no statistically significant difference between cholesteatoma and non-cholesteatoma groups in terms of HU densities. Intraclass correlation coefficient test showed an intraclass correlation of 0.41 between measurements done by radiologists and otorhinolaryngologists, which showed poor reliability. Contrary to previous studies in unoperated ears, in operated ears HU density at aditus level cannot be a reliable diagnostic adjunct. Moreover, when it is considered that interrater reliability was poor between radiologists' and otolaryngologists' measurements, a need for further studies arise to solidify findings in this study. Key Words: Cholesteatoma diagnostic imaging, Middle ear surgery, Revision mastoidectomy.

Diagnostic Utility of C4d by Direct Immunofluorescence in Bullous Pemphigoid.

Bullous pemphigoid (BP) is an autoimmune blistering disease that commonly affects elderly patients. Direct immunofluorescence (DIF) for immunoglobulin G (IgG) and C3c on frozen skin biopsies is the gold standard for the diagnosis of BP. In a minority of cases, IgG and/or C3c are found negative, and in these situations, there is a need for a more stable diagnostic marker of BP. C4d is biologically inactive, but has a long half-life, rendering it a long-lived marker for antibody-mediated complement activation. Previous studies already demonstrated that C4d was diagnostically useful in formalin-fixed paraffin-embedded skin biopsies of patients with BP. We hypothesized that C4d detected by DIF could also be a promising diagnostic marker for BP, particularly in IgG and/or C3c DIF-negative cases. In this single-center retrospective study, 69 cases of BP were analyzed for linear deposition of C4d; of the 69 cases, n = 26 were IgG+/C3c-, n = 10 IgG+/C3c+, and n = 33 IgG-/C3c-. Results were compared with n = 39 negative controls. Seven of the 26 (27%) IgG+/C3c- and 3 of the 33 (9%) IgG-/C3c- BP cases were positive for C4d. All 10 IgG+/C3c+ cases were also C4d positive. In the negative control group, 2 of the 39 (5%) were found positive for C4d. In conclusion, the current study shows that C4d is a more sensitive but not a 100% specific marker of BP. We conclude that C4d by DIF could be an interesting diagnostic adjunct for BP, particularly in IgG-/C3c- double negative cases.

SAT B2 a novel diagnostic adjunct in a rare presentation of extra skeletal osteosarcoma of scrotum

SATB2 is a nuclear protein that plays a critical role in osteoblast lineage commitment. Diagnosing extra skeletal osteosarcomas at rare sites can be quite challenging as it might mimic hyalinized stroma. The utility of SATB2 expression in osteosarcomas and other bone and soft tissue tumours is an useful adjunct to histopathology in diagnosing these rare lesions. A 69 year old male, presented with scrotal swelling since 8 months. He underwent left sided orchidectomy because of the clinical suspicion of malignancy. Macroscopy revealed a solid mass in the para testicular tissue with no involvement of the testicular tissue. Cut surface is whitish, firm and homogenous. Microscopy showed malignant soft tissue tumor with areas showing osteoid differentiation and SAT B2 helped in confirmation of diagnosis by highlighting the osteoblastic nature of cells. Hence a diagnosis of Primary extra skeletal paratesticular osteosarcomas was made.

The Many Uses of p53 Immunohistochemistry in Gynecological Pathology: Proceedings of the ISGyP Companion Society Session at the 2020 USCAP Annual9 Meeting.

Ancillary immunohistochemistry (IHC) has become a reliable adjunct for subclassification of gynecological neoplasms. An important recent development was optimization and validation of p53 IHC, where 3 abnormal IHC patterns (nuclear overexpression, complete absence, cytoplasmic) were shown to predict underlying TP53 mutations with high accuracy in ovarian carcinomas. p53 IHC now helps in distinguishing high-grade serous from low-grade serous carcinomas. Thereafter, the new interpretation of p53 IHC was quickly adapted for other purposes and similar accuracies were shown in endometrial carcinomas, vulvar squamous cell carcinomas, and ovarian mucinous tumors. However, it required further refinement of the p53 IHC interpretation criteria for each tumor site. A proportion of endometrial endometrioid carcinomas shows an ultramutated or hypermutated genotype due to underlying POLE mutations or mismatch repair deficiency sometimes causing subclonal TP53 mutations, and their distribution can be visualized by p53 IHC. Squamous cell carcinomas and ovarian mucinous tumors show a phenomenon called terminal differentiation where basal cells demonstrate an abnormal pattern of p53 IHC but apical cells do not despite an underlying TP53 mutation. High-grade progression of adult granulosa cell tumors due to a subclonal TP53 mutation has been recently described. Another use of p53 IHC is triaging gynecological sarcomas for molecular testing based on the assumption that TP53-mutated gynecological sarcomas do not harbor cancer driving translocations. Therefore, familiarity with interpretation of p53 IHC is becoming increasingly important for the practicing gynecological pathologist. Furthermore, local optimization of the p53 IHC assay using validated protocols including appropriate low expressing control tissues (eg, tonsil) is vital in order to achieve high diagnostic accuracy, especially for abnormal staining patterns such as complete absence or cytoplasmic, and interlaboratory concordance. p53 IHC is a reliable diagnostic adjunct for histotyping and molecular subtyping of ovarian and endometrial carcinomas, and it paves the way for large-scale studies to validate the prognostic value of p53 IHC in several gynecological tumor types. The technical advances, validated interpretation criteria, and its growing versatility in identifying high-risk neoplasms paired with its widespread availability in pathology departments make p53 IHC perhaps the single most useful IHC stain in gynecological pathology.