Discrepant Cases Research Articles

Retrospective Study on Accuracy of Intraoperative Frozen Section Biopsy in Spinal Tumors

Histologic types and grades are critical in the diagnosis and treatment of spinal tumors. Intraoperative frozen section is a fast and easy method in confirming pathologic diagnosis during the operation. This study was undertaken to reveal the accuracy of intraoperative frozen section biopsy in order to make proper treatment plans. This retrospective study concerned patients who underwent spinal tumor surgeries from 1 January, 2012 to 31 December, 2016. Frozen section biopsy and permanent biopsy were compared, and cases that had differences were counted. Thirty-seven cases out of 324 patients had discrepancies (11.4%). In discrepant cases 11 cases were ependymoma (29.7%) and 6 cases were schwannoma (16.2%). Among 34 patients who were finally diagnosed with an ependymoma, 11 cases had discrepancies, which was the highest mismatch rate among tumor final pathologic types. By frozen biopsy, astrocytoma (n= 5) and ependymoma (n= 5) turned out to be the most discrepant pathologic types and 16 frozen section biopsy cases were "null." Frozen biopsy astrocytoma (n= 5) mostly turned out to be ependymoma in 4 cases. Pathologic findings from frozen biopsy for spinal cord tumors could not be corresponded to final diagnosis, especially when the results of frozen biopsy were ependymoma or astrocytoma. Therefore careful decision making for treatment plans is required.

A comparison between phase diagram modelling of metamafic rocks and experimental and independent thermobarometric data

The use of equilibrium phase diagrams such as pseudosections has become widespread in recent years, but few studies tested the phase relations predicted by these models. This work aims at comparing predicted phase relations with mineral assemblages observed in experimental products and in natural samples, in this latter case using as reference metamorphic conditions pressures and temperatures determined for metapelites metamorphosed under the same conditions as the mafic rocks. Pseudosections were calculated with THERMOCALC for six mafic bulk-rock compositions, in the range 425–700 °C and 2–8 kbar. The resulting diagrams can be divided into two groups: one in which a classic sequence of mineral assemblages occur and another where quartz is unstable and diopside is stable throughout. The results compare well to the independent data in three of the six studied cases. The main inconsistencies found in the pseudosections are underestimation of the stability field of garnet and overestimation of the stability fields of diopside and hornblende, which is at odds not only with data specific to the rocks studied here, but with the literature on metamafic rocks in general. In the case of garnet, the most likely case of discrepancy is the absence of Mn in the activity-composition models available. On the other hand, the issue with diopside and hornblende is much harder to evaluate, as it may be related to any of the activity-composition models, or to relationships between two or more of them. Nonetheless, we can affirm that the overestimation of the diopside stability field is related to SiO2 content, although there are other factors that influence it.

Distinctions of the results of automated analysis and microscopic blood investigation (examples of clinical cases).

There are cases of discrepancies between the results of a microscopic examination of blood cells by morphological physicians with data obtained using an automatic analyzer in patients with a hematologic profile. It is shown that in some cases the analyzer does not determine changes in the morphology of erythrocytes, allows errors in calculating the leukoformula, differentiation of cells according to the degree of maturity, and evaluation of the number of platelets. The complementary importance of methods of light microscopy and automated blood analysis in patients with suspected pathology of the blood system is underlined.

SAT-612 An Anti-Idiotype Antibody to T3 Measurements: A Misleading Cause of Inappropriate TSH Secretion

Background: Measurements of thyrotropin (TSH), total and free thyroxine (TT4,FT4), triiodothyronine (TT3,FT3) are widely used diagnostic methods for thyroid function evaluation. However, some serum samples demonstrate a nonspecific binding with assay reagents that can interfere with the measurement of these hormones. Several steps can be taken to identify results that may reflect the presence of interfering factors including: 1) discrepancies between current values and previous results using the same methods; 2) clues from the clinical setting; 3) the pattern of discrepant and non-discrepant thyroid profile results (1,2) Clinical case: A 67-year-old woman admitted with generalized muscle weakness for one week. On physical examination she had left facial palsy (LMN), dysarthria, motor power grade 1 in her lower extremities and grade 3 in her upper extremities, her deep tendon reflex was diminished and her peripheral sensation was decreased as glove and stocking pattern. She was also experiencing normal anal sphincter tone and perianal sensation. She was diagnosed with hypertension and she was prescribed atenolol for treatment. She was clinically euthyroid. Provisional clinical diagnosis was Guillain-Barre syndrome. Because her laboratory profile showed hyponatremia, the following thyroid function tests were ordered: TSH 7.090 mIU/L (0.27-4.20 normal range [NR]); FT3 13.33 pg/ml (2.00-4.40 NR); FT4 1.37 ng/dl (0.93-1.70 NR) tested by one-step electrochemiluminescent immunoassay (ECLIA,Roche platform,Cobas®);anti-thyroid peroxidase antibody (16.25 IU/ml, normal); anti-thyroglobulin antibody (<10 IU/ml); serum morning cortisol concentration, normal. The thyroid profile was repeated on new samples from the same patient 3 and 7 days later. The results confirmed mildly elevated TSH with high FT3 concentration but normal FT4. Then, the thyroid profile also was processed in a different laboratory using a different technique (Abbott® platform). Using this platform, the FT3, FT4 and TSH were all within reference ranges. To confirm that the sample contained an interfering, an aliquot also was sent to Roche for further analysis. The results showed that the patient had antibodies to anti-idiotype of both the T3 and FT3 assays. Conclusion To avoid misdiagnosis or inappropriate treatment decisions, when there are discrepancies between the clinical setting and the thyroid function tests, the clinician should always consider that there is a substance interfering with the assay.

Detection of breast cancer lymph node metastases in frozen sections with a point-of-care low-cost microscope scanner

BackgroundDetection of lymph node metastases is essential in breast cancer diagnostics and staging, affecting treatment and prognosis. Intraoperative microscopy analysis of sentinel lymph node frozen sections is standard for detection of axillary metastases but requires access to a pathologist for sample analysis. Remote analysis of digitized samples is an alternative solution but is limited by the requirement for high-end slide scanning equipment.ObjectiveTo determine whether the image quality achievable with a low-cost, miniature digital microscope scanner is sufficient for detection of metastases in breast cancer lymph node frozen sections.MethodsLymph node frozen sections from 79 breast cancer patients were digitized using a prototype miniature microscope scanner and a high-end slide scanner. Images were independently reviewed by two pathologists and results compared between devices with conventional light microscopy analysis as ground truth.ResultsDetection of metastases in the images acquired with the miniature scanner yielded an overall sensitivity of 91% and specificity of 99% and showed strong agreement when compared to light microscopy (k = 0.91). Strong agreement was also observed when results were compared to results from the high-end slide scanner (k = 0.94). A majority of discrepant cases were micrometastases and sections of which no anticytokeratin staining was available.ConclusionAccuracy of detection of metastatic cells in breast cancer sentinel lymph node frozen sections by visual analysis of samples digitized using low-cost, point-of-care microscopy is comparable to analysis of digital samples scanned using a high-end, whole slide scanner. This technique could potentially provide a workflow for digital diagnostics in resource-limited settings, facilitate sample analysis at the point-of-care and reduce the need for trained experts on-site during surgical procedures.

Gaia Data Release 2 distances and peculiar velocities for Galactic black hole transients

We report on a first census of Galactic black hole X-ray binary (BHXRB) properties with the second data release (DR2) of {\em Gaia}, focusing on dynamically confirmed and strong candidate black hole transients. DR2 provides five-parameter astrometric solutions including position, parallax and proper motion for 11 of a sample of 24 systems. Distance estimates are tested with parallax inversion as well as Bayesian inference. We derive an empirically motivated characteristic scale length of $L$=2.17$\pm$0.12 kpc for this BHXRB population to infer distances based upon an exponentially decreasing space density prior. Geometric DR2 parallaxes provide new, independent distance estimates, but the faintness of this population in quiescence results in relatively large fractional distance uncertainties. Despite this, DR2 estimates generally agree with literature distances. The most discrepant case is BW Cir, for which detailed studies of the donor star have suggested a distant location at >~25 kpc. A large DR2 measured parallax and relatively high proper motion instead prefer significantly smaller distances, suggesting that the source may instead be amongst the nearest of XRBs. However, both distances create problems for interpretation of the source, and follow-up data are required to resolve its true nature. DR2 also provides a first distance estimate to one source, MAXI J1820+070, and novel proper motion estimates for 7 sources. Peculiar velocities relative to Galactic rotation exceed $\sim$ 50 km s$^{-1}$ for the bulk of the sample, with a median system kinetic energy of peculiar motion of $\sim$ 5 $\times$ 10$^{47}$ erg. BW Cir could be a new high-velocity BHXRB if its astrometry is confirmed. A putative anti-correlation between peculiar velocity and black hole mass is found, as expected in mass-dependent BH kick formation channels, but this trend remains weak in the DR2 data.

Next-Generation Sequencing (NGS) Methods Show Superior or Equivalent Performance to Non-NGS Methods on BRAF, EGFR, and KRAS Proficiency Testing Samples.

There has been a rapid expansion of next-generation sequencing (NGS)-based assays for the detection of somatic variants in solid tumors. However, limited data are available regarding the comparative performance of NGS and non-NGS assays using standardized samples across a large number of laboratories. To compare the performance of NGS and non-NGS assays using well-characterized proficiency testing samples provided by the College of American Pathologists (CAP) Molecular Oncology Committee. A secondary goal was to compare the use of preanalytic and postanalytic practices. A total of 17 343 responses were obtained from participants in the BRAF, EGFR, KRAS, and the Multigene Tumor Panel surveys across 84 different proficiency testing samples interrogating 16 variants and 3 wild-type sequences. Performance and preanalytic/postanalytic practices were analyzed by method. While both NGS and non-NGS achieved an acceptable response rate of greater than 95%, the overall performance of NGS methods was significantly better than that of non-NGS methods for the identification of variants in BRAF (overall 97.8% versus 95.6% acceptable responses, P = .001) and EGFR (overall 98.5% versus 97.3%, P = .01) and was similar for KRAS (overall 98.8% and 97.6%, P = .10). There were specific variant differences, but in all discrepant cases, NGS methods outperformed non-NGS methods. NGS laboratories also more consistently used preanalytic and postanalytic practices suggested by the CAP checklist requirements than non-NGS laboratories. The overall analytic performance of both methods was excellent. For specific BRAF and EGFR variants, NGS outperformed non-NGS methods and NGS laboratories report superior adherence to suggested laboratory practices.

Acute necrotising pancreatitis - causes of deaths: single-centre retrospective study

Relevance. There is a discussion about the prevalence of early or late mortality and the main causes of death in different phases of acute pancreatitis. Analysis of mortality is important for the determination of ways to improve the results of treatment of pancreatic necrosis.&#x0D; Aim of the research is analysis of the structure, timing characteristics and causes of deaths in pancreatic necrosis, the effect of the configuration of parapancreatitis and surgical tactics on the outcome of the disease.&#x0D; Materials and methods. Retrospective single-center study of lethal outcomes in acute pancreatitis was performed, the structure of mortality, cases of discrepancies in diagnoses, the timing of the onset and causes of deaths of patients were studied. The lethal outcomes were compared in the operated patients, the frequency of the mesentery root involvement, the indications and the timing of the interventions were assessed.&#x0D; Results. The ratio of early and late mortality was 45,2% to 54,8%, respectively. The main causes of early mortality – endotoxin shock and multi-organ failure, late one – infectious complications. In 9,6% of the patients, the diagnosis was made only with an autopsy. The prognostic value of the SOFA and SAPS II scales is characterized as low. The tactics of surgical treatment has changed in favour of minimally invasive surgery. The average conversion time for ineffective percutaneous procedures was 21,4 days. The involvement of mesentery in parapancreatitis was often accompanied by a breakthrough of the abscess into the abdominal cavity.&#x0D; Conclusion. The surgical component of the reduction in mortality is the rejection of unreasonable surgical interventions, the earlier conversion to "traditional" operations in case of ineffective minimally invasive treatment and the allocation of "central" localization of parapancreatitis as a serious prognostic factor of the course of severe pancreatitis.

Abstract GS3-07: Clinical utility of circulating tumor cell count as a tool to chose between first line hormone therapy and chemotherapy for ER+ HER2- metastatic breast cancer: Results of the phase III STIC CTC trial

Abstract Background: In ER+ HER2- metastatic breast cancer (MBC) patients, the clinical choice between 1st line hormone therapy (HT, the recommended option) or chemotherapy (CT) is based on the absence of “visceral crisis” or adverse prognostic factors, with no proven/objective criteria. In that context, STIC CTC (NCT01710605) was set up as a strategy trial to test whether circulating tumor cells (CTC) count could help customize the choice between 1st line HT or CT. Methods: For this multicenter phase 3 non-inferiority trial, the main inclusion criteria were: ER+ HER2- MBC with no prior therapy, PS≤2, no contra-indication to HT or CT and informed consent. The a priori treatment choice (HT or CT) and CTC count (CellSearch®) were obtained in all patients prior to randomization. Patients were randomized 1:1 between clinically-driven choice (CTC count not disclosed, HT or CT administered as decided a priori), or a CTC-driven choice (HT if &amp;lt;5 CTC/7.5ml, CT if ≥5 CTC/7.5ml). The primary objective was treatment efficacy (PFS hazard ratio), non-inferiority being established if the upper bound of the PFS HR 2-sided 90%CI is ≤1.25; secondary objectives included subgroup analyses (CTC status, patient characteristics) and OS. Results: 761 MBC patients were randomized between 02/2012 and 08/2016. Baseline characteristics: 7.8% of patients had a PS=2, 24.1% had a de novo metastatic disease; 63.3% received prior adjuvant HT and 49.9% prior adjuvant CT; 31.3% had ≥3 metastatic sites. A priori treatments (HT or CT) and CTC count (&amp;lt; or ≥5 CTC/7.5ml) were well balanced between the two arms. After randomization, in the clinically-driven arm, N=267 (72.4%) patients received HT and N=102 (27.6%) CT (as decided a priori). In the CTC-driven arm: (1) the a priori choice of HT was confirmed by a low CTC count in N=181 (67.5%) of patients, while N=87 (32.5%) were switched to CT due to a high CTC count; (2) the a priori choice of CT was confirmed by high CTC count in only N=48 (48%) patients, while N=52 (52%) were switched to HT. The primary endpoint was met, PFS being not inferior in the CTC-driven arm (HR=0.98, 90%CI=[0.84–1.13]). Analyses focusing on discordant subgroups showed that for patients with a priori choice of HT but with high CTC count (leading to a switch to CT in the CTC-arm), PFS was significantly longer in the CTC-driven arm than in the standard arm (HR=0.67, 95%CI=[0.49–0.92]; p=0.01), with a non-significant trend toward longer OS (HR=0.68, 95%CI=[0.44–1.07]; p=0.09). Inversely, for patients with a priori choice of CT but with low CTC count (i.e. de-escalation to HT in the CTC arm), PFS was not statistically different between the two arms. Conclusion: This trial demonstrates the clinical utility of CTC count as an objective decision tool when considering 1st line therapy in ER+ HER2- MBC. In most patients, CTC count did confirm the a priori clinical choice; however, trial results show that in discrepant cases, CTC count may be trusted for either escalating (i.e. considering CT in patients if high CTC count) or de-escalating (i.e. considering HT in patients if low CTC count) 1st line therapy. Funding: French National Cancer Institute; Menarini Silicon Biosystems. Citation Format: Bidard F-C, Jacot W, Dureau S, Brain E, Bachelot T, Bourgeois H, Goncalves A, Ladoire S, Naman H, Dalenc F, Gligorov J, Espie M, Levy C, Ferrero J-M, Loirat D, Cottu P, Dieras V, Simondi C, Berger F, Alix-Panabieres C, Pierga J-Y. Clinical utility of circulating tumor cell count as a tool to chose between first line hormone therapy and chemotherapy for ER+ HER2- metastatic breast cancer: Results of the phase III STIC CTC trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS3-07.

The FDA-Approved Breast Cancer HER2 Evaluation Kit (HercepTest; Dako) May Miss Some HER2-Positive Breast Cancers.

Accurate evaluation of human epidermal growth factor receptor 2 (HER2) in breast cancer is critical. HER2 fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) tests were performed on 52 cases using a US Food and Drug Administration (FDA)-approved kit (HercepTest, FDA kit) and a laboratory-developed test (LDT) with the HercepTest antibody and a Leica Bond automated stainer. By FISH, 22 were HER2 positive, 29 were negative, and one was equivocal. Of the 22 HER2 FISH-positive cases, five were negative by the FDA kit and none by LDT. The five discrepant cases were retested using the same FDA kit in another Clinical Laboratory Improvement Amendments-certified laboratory, and all five cases were still negative. None of the 29 HER2 FISH-negative cases were positive by the FDA kit or LDT. The overall IHC-FISH concordance rate was 90.4% for the FDA kit and 100% for the LDT. The FDA kit may miss some HER2-positive cases. The LDT has a higher sensitivity and a higher concordance rate with FISH results.

Intraoperative Frozen Cytology of Central Nervous System Neoplasms: An Ancillary Tool for Frozen Diagnosis.

BackgroundPathologic diagnosis of central nervous system (CNS) neoplasms is made by comparing light microscopic, immunohistochemical, and molecular cytogenetic findings with clinicoradiologic observations. Intraoperative frozen cytology smears can improve the diagnostic accuracy for CNS neoplasms. Here, we evaluate the diagnostic value of cytology in frozen diagnoses of CNS neoplasms.MethodsCases were selected from patients undergoing both frozen cytology and frozen sections. Diagnostic accuracy was evaluated.ResultsFour hundred and fifty-four cases were included in this retrospective single-center review study covering a span of 10 years. Five discrepant cases (1.1%) were found after excluding 53 deferred cases (31 cases of tentative diagnosis, 22 cases of inadequate frozen sampling). A total of 346 cases of complete concordance and 50 cases of partial concordance were classified as not discordant cases in the present study. Diagnostic accuracy of intraoperative frozen diagnosis was 87.2%, and the accuracy was 98.8% after excluding deferred cases. Discrepancies between frozen and permanent diagnoses (n = 5, 1.1%) were found in cases of nonrepresentative sampling (n = 2) and misinterpretation (n = 3). High concordance was observed more frequently in meningeal tumors (97/98, 99%), metastatic brain tumors (51/52, 98.1%), pituitary adenomas (86/89, 96.6%), schwannomas (45/47, 95.8%), high-grade astrocytic tumors (47/58, 81%), low grade astrocytic tumors (10/13, 76.9%), non-neoplastic lesions (23/36, 63.9%), in decreasing frequency.ConclusionsUsing intraoperative cytology and frozen sections of CNS tumors is a highly accurate diagnostic ancillary method, providing subtyping of CNS neoplasms, especially in frequently encountered entities.

Fine needle aspiration cytology of minor salivary gland tumors: A retrospective 5-year study of 42 cases in a tertiary care hospital.

Minor salivary gland tumors (MSGTs) are less common than major salivary glands and involve only 15-20% of all salivary gland tumors. Most of the cases originate at intra- and peri-oral region. Minor salivary gland lesion cytology has been studied rarely in India. This present study was performed to evaluate the role of fine needle aspiration cytology (FNAC) in diagnosis of MSGTs and to explore the cases of cytohistological discrepancies in the study. This retrospective study was conducted over a 5-year period on 42 cases of MSGTs. In all the cases, cytology was correlated with histology and cytohistological discrepancies were searched. Sensitivity, specificity, and diagnostic efficacy were calculated using histopathology as gold standard. We diagnosed 27 malignant (64.28%) and 15 benign (35.71%) MSGTs in cytological evaluation. We found two false negative and one false positive case in cytology. Sensitivity, specificity, and diagnostic accuracy of the study were 92.59%, 93.33%, and 92.85%, respectively. FNAC is a minimally invasive and cost-effective procedure with high accuracy (92.85%) in the assessment of MSGTs and helps in the management of benign and malignant tumors.

Quality of diagnosing acute poisoning by ambulance paramedics

Aim. The assessment of quality of diagnosing acute poisoning by ambulance paramedics.&#x0D; Methods. Retrospective analysis of the rate of diagnostic discrepancies and undifferentiated diagnoses in 1 242 patients delivered by ambulance paramedics of Kazan to the hospital with the diagnosis of acute poisoning.&#x0D; Results. Referral diagnosis of acute poisoning among patients delivered by ambulance paramedics to the diagnostic department of the hospital was not confirmed in 792 cases, among which in 683 cases admission was not needed due to the absence of indications. Among refusals of hospitalization the majority of patients (70.8 %) were in the state of intoxication of various etiologies and healthy patients. In 8.5 % of cases of diagnostic discrepancies of acute poisoning paramedics delivered to the hospital patients with severe urgent somatic pathology - urosurgical, neurological, surgical, therapeutic, etc. The rate of diagnostic discrepancies in the group of alcohol, drug, undefined substances and mushroom intoxication was higher - 71.5 %, than in the group of medication and carbon monoxide intoxication - 39.7 %. In poisoning with impaired consciousness a direct dependence of the rate of diagnostic discrepancies on the rate of impaired consciousness was observed. The rate of undifferentiated diagnoses in the first group of poisoning was also higher - 82.3 %, than in the second group - 45. 8%, but no dependence on the impairment of consciousness was observed among patients.&#x0D; Conclusion. High rate of diagnostic discrepancies (63.8 %) and undifferentiated diagnoses (71.1 %) are the consequence of lack of competence in medical toxicology among ambulance paramedics. In 98.2 % of cases, the probable etiological diagnosis of the disease, suspected as acute poisoning, in the study group of patients could be diagnosed using diagnostic methods available for paramedics.

MSIpred: a python package for tumor microsatellite instability classification from tumor mutation annotation data using a support vector machine

Microsatellite instability (MSI) is characterized by high degree of polymorphism in microsatellite lengths due to deficiency in mismatch repair (MMR) system. MSI is associated with several tumor types and its status can be considered as an important indicator for patient prognosis. Conventional clinical diagnosis of MSI examines PCR products of a panel of microsatellite markers using electrophoresis (MSI-PCR), which is laborious, costly, and time consuming. We developed MSIpred, a python package for automatic MSI classification using a machine learning technology – support vector machine (SVM). MSIpred computes 22 features characterizing tumor somatic mutational load from mutation data in mutation annotation format (MAF) generated from paired tumor-normal exome sequencing data, subsequently using these features to predict tumor MSI status with a SVM classifier trained by MAF data of 1074 tumors belonging to four types. Evaluation of MSIpred on an independent testing set, MAF data of another 358 tumors, achieved overall accuracy of ≥98% and area under receiver operating characteristic (ROC) curve of 0.967. Further analysis on discrepant cases revealed that discrepancies were partially due to misclassification of MSI-PCR. Additional testing of MSIpred on non-TCGA data also validated its good classification performance. These results indicated that MSIpred is a robust pan-tumor MSI classification tool and can serve as a complementary diagnostic to MSI-PCR in MSI diagnosis.

Comparative Analysis between RQ-PCR, Digital-Droplet-PCR and Next-Generation-Sequencing (NGS) of Immunoglobulin/T-Cell Receptor Gene Rearrangements to Monitor Minimal Residual Disease in Adult Acute Lymphoblastic Leukemia Patients

▪Background. Minimal residual disease (MRD) is the strongest prognostic factor in both children and adults with acute lymphoblastic leukemia (ALL). Currently, it is most widely monitored by molecular methods based on real-time-quantitative-PCR (RQ-PCR). Digital-droplet-PCR (ddPCR) and next-generation-sequencing (NGS) represent advanced tools that have the potential to overcome some limitations of standard approaches and potentially provide additional benefits. We analyzed adult ALL follow-up (FU) samples by RQ-PCR, ddPCR and NGS in order to better define the discriminating power of these novel methods.Patients and Methods. Thirty adult ALL patients enrolled in the GIMEMA LAL 1913 protocol and their 83 FU bone marrow (BM) samples were studied. All patients received homogeneous induction/early consolidation chemotherapy, with concurrent MRD analysis at four time-points, to optimize risk classification and support risk/MRD-oriented therapy. RQ-PCR analyses followed the EuroMRD Consortium guidelines (van der Velden, 2007), ddPCR was performed as published (Della Starza, 2016; Cavalli, 2017) and NGS, as previously described (Faham, 2012; Kotrova M, 2017).Results. By MRD RQ-PCR analysis, 19/83 samples were positive and quantifiable (Q), 9/83 were positive not-quantifiable (PNQ) and 55/83 were negative (NEG). By MRD ddPCR analysis, 27/83 samples were Q, 1/83 sample was PNQ and 55/83 proved NEG. Comparing the results of the two methods, we observed that MRD detection was concordantly positive or negative in 81% (67/83) of FU samples, while 19% (16/83) samples were classified as discordant. Most of the discordances occurred in samples with low levels of disease, i.e. PNQ or NEG: 9/83 were RQ-PCR PNQ, 4 of which were Q by ddPCR and 5 were ddPCR NEG. In the remaining 7 discordant FU samples, 5 were RQ-PCR NEG/ddPCR Q, 1 sample was RQ-PCR Q /ddPCR NEG and 1 sample was RQ-PCR NEG/ddPCR PNQ. The use of ddPCR significantly reduced the proportion of PNQ samples if compared to RQ-PCR - 1/83 (3%) vs 9/83 (15%) - respectively (p=0.0179), increasing the proportion of Q samples: 27/83 (33%) vs 19/83 (23%). It is worth noting that ddPCR also quantified the levels of disease in 9% (5/55) of samples, that were RQ-PCR NEG (Table 1).MRD analysis was also performed by NGS in 41 samples from 15 patients: 18/41 samples proved Q and 23/41 were NEG. Comparing the MRD detection obtained by both ddPCR and NGS, we observed a concordant result in 98% (40/41) of samples; only 1 sample was ddPCR NEG and NGS Q with a MRD level of 1x10-5. The concordance between RQ-PCR and NGS was 78% (32/41 samples). Moreover, among these 41 samples 9 (from 7 patients) were discordant between RQ-PCR and ddPCR in the first comparative analysis: in 4 RQ-PCR-NEG FU samples, 3 were Q by both ddPCR and NGS, 1 was ddPCR NEG and NGS Q, with a MRD level of 10- 5; 1 subsequent relapse was observed; 4 FU samples that were RQ-PCR-PNQ/ddPCR-Q, were Q also by NGS; 1 subsequent relapse was observed. Finally, 1 RQ-PCR-PNQ sample was negative by both ddPCR and NGS, and no recurrence has so far been observed. Moreover, in the cohort of samples analyzed only by RQ-PCR and ddPCR, in 1 RQ-PCR NEG/ddPCR Q sample a relapse was observed, while the only case that was RQ-PCR Q/ddPCR NEG has so far not relapsed. Notably, 2 of the 3 relapses were documented in patients who were, at decisional treatment TPs, RQ-PCR PNQ or NEG and ddPCR/NGS Q.Conclusions. When MRD levels are very low, it can be difficult to dissect if the not-quantifiable signal observed by PCR is due to few residual leukemic cells or to a non-specific amplification of normal DNA. The superior sensitivity and accuracy of ddPCR and NGS could be instrumental to univocally define these samples, which presently represent a problematic gray area in the clinical practice of MRD-driven protocols and might be associated with clinical relapse: indeed, among 83 FU samples analyzed we observed 3 relapses, whose FU samples were classified as PNQ or NEG by RQ-PCR, but proved Q by ddPCR and/or NGS. At variance, no relapses were recorded in patients whose FU samples were defined RQ-PCR-PNQ, but proved ddPCR/NGS NEG. Moreover, in 2/3 relapsed cases the change of MRD status (PNQ or NEG vs Q) could have led to a switch in risk classification and therefore in a treatment change. Further studies with a larger number of discrepant cases and a longer FU time will allow to conclusively define the clinical application and implication of these new methods. [Display omitted] DisclosuresChiaretti:Shire: Consultancy; Pfuzer: Consultancy; Amgen: Consultancy; Incyte: Consultancy. Foà:NOVARTIS: Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau; CELTRION: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; INCYTE: Other: ADVISORY BOARD; AMGEN: Other: ADVISORY BOARD; GILEAD: Speakers Bureau.

Rare cases of laboratory tests discrepancies in diagnostics of pediatric Burkitt lymphoma/leukemia

Introduction. The main features of bone marrow blasts cells in Burkitt lymphoma/leukemia (BL) are L3 morphology, mature immunophenotype of blasts with surface IgM expression, and presence of typical MYC gene rearrangements.The aim of the study was to show discrepancy examples in laboratory signs of BL.Patients and methods. 10 patients (8 boys and 2 girls) aged 1 to 18 years were included in the present study. The inclusion criterion was the identification of discrepancies between flow cytometric, morphological and cytogenetic data.Results. In 2 cases there were no rearrangements of the MYC gene. In 2 patients, the L2 morphological variant went against the presence of typical MYC gene rearrangements. In one case, undifferentiated blasts cells were described by morphology together with presence of surface IgM, and atypical genetics. In 8 patients, there was no expression of surface IgM. Of these, patients with absence of cytomorphological data cytometric and genetic data were controversial.Сonclusion. The cases presented in this study and the cases described in the literature demonstrate the importance of an attentive and comprehensive approach in evaluating the results of laboratory tests in the diagnosis of BL.

MA26.06 Crizotinib-Treated ALK Immunopositive Metastasized NSCLC is Associated with an Unfavorable Prognosis when FISH Negative

Background Metastasized NSCLC with an ALK fusion are sensitive to a range of tyrosine kinase inhibitors. ALK-positive NSCLC has been identified in the pivotal phase III trial with fluorescence in situ hybridization (ALK FISH+). These tumors are also expressing the fusion product (ALK immunohistochemistry (IHC)+). However, discrepant cases occur, including ALK IHC+ FISH-. The aim of this study was to collect ALK IHC+ cases and compare within this group response to crizotinib treatment of ALK FISH+ cases with ALK FISH- cases. Method A prospective multicenter investigator initiated research study was started in Europe. Stage IV ALK IHC+ NSCLC cases treated with crizotinib were collected centrally. Slides were validated centrally for ALK IHC (with 5A4 ETOP and D5F3 Ventana protocol) and ALK FISH (Vysis probes). Result The study started April 1, 2014 and closed in November 2017. Fifteen centers participated. Registration of 3523 ALK IHC tests revealed prevalence of 2.6% ALK IHC+ cases. Local ALK FISH analysis resulted in 46 concordant (ALK IHC+/FISH+) and 18 discordant (ALK IHC+/FISH-) cases. Central validation revealed 37 concordant and 6 discordant cases, 5 of which had follow-up. Validation was hampered by limited amount of tissue in biopsy samples. The time to treatment failure did not differ for concordant nor discordant cases, and neither for local nor validated ALK testing (HR=0.78; 95% CI= 0.27-2.3; p=0.64) and (HR=2.2; 95% CI= 0.72-6.5; p=0.16), respectively). However, overall survival was significantly better for concordant cases than discordant cases after central validation (HR=4.5; 95% CI= 1.2-15.9; p=0.010), but not according to local testing (HR=1.7; 95% CI= 0.45-6.2; p=0.44). Conclusion ALK IHC+ FISH- NSCLC cases are an infrequent finding. We recommend such cases to be validated carefully because our data indicate that ALK IHC+ FISH- cases have a worse survival when treated by crizotinib compared to ALK IHC+ FISH+ cases. This study was funded by an independent research grant by Pfizer.

The prognostic value of androgen receptors in breast cancer subtypes.

Androgen receptor (AR) expression is frequent in breast cancer and has been associated with good prognosis in several studies. The present study investigates AR-expression in relation to molecular subtypes, clinicopathological features and prognosis in 1297 primary tumours and 336 paired axillary lymph node metastases (LNM) from two cohorts of Norwegian patients. Immunohistochemistry for AR was performed on tumours previously reclassified into molecular subtypes using immunohistochemistry and in situ hybridisation. Associations between AR-expression and clinical features were studied using Chi-square tests. Cumulative incidence of breast cancer death and Cox regression analyses were used to assess prognosis. AR-positivity was found in 78.0% of all cases, 84.9% of luminal and 45.1% of non-luminal tumours. The highest proportion of AR-positivity was found in Luminal B tumours, and the lowest in the Basal phenotype. Discordance in AR-status between primary tumours and lymph node metastases was observed in 21.4% of cases. A switch from AR- primary tumour to AR+ lymph node metastasis was seen in 60/72 discrepant cases. AR-expression in primary tumours was an independent and favourable prognostic marker (HR 0.70, 95% CI 0.55-0.90), particularly in the Luminal A subtype, and in grade 3 tumours. AR is an independent predictor of good prognosis in BC, particularly in grade 3 and Luminal A tumours. Discordant AR-expression between primary tumour and LNM was observed in 21.4% of cases and most often there was a switch from AR- primary tumour to AR+ axillary LNM.

Linking HIV and Viral Hepatitis Surveillance Data: Evaluating a Standard, Deterministic Matching Algorithm Using Data From 6 US Health Jurisdictions.

Accurate interpretations and comparisons of record linkage results across jurisdictions require valid and reliable matching methods. We compared existing matching methods used by 6 US state and local health departments (Houston, Texas; Louisiana; Michigan; New York, New York; North Dakota; and Wisconsin) to link human immunodeficiency virus and viral hepatitis surveillance data with a 14-key automated, hierarchical deterministic matching method. Applicable years of study varied by disease and jurisdiction, ranging from 1979 to 2016. We calculated percentage agreement and Cohen's κ coefficient to compare the matching methods used within each jurisdiction. We calculated sensitivity, specificity, and positive predictive value for each matching method, as compared with a new standard that included manual review of discrepant cases. Agreement between the existing matching method and the deterministic matching method was 99.6% or higher in all jurisdictions; Cohen's κ values ranged from 0.87 to 0.98. The sensitivity of the deterministic matching method ranged from 97.4% to 100% in the 6 jurisdictions; specificity ranged from 99.7% to 100%; and positive predictive value ranged from 97.4% to 100%. Although no gold standard exists, prior assessments of existing methods and review of discrepant classifications suggest good accuracy and reliability of our deterministic matching method, with the advantage that our method reduces the need for manual review and allows for standard comparisons across jurisdictions when linking human immunodeficiency virus and viral hepatitis data.

Outcomes of Physeal-Sparing ACL Reconstruction with Iliotibial Band Autograft in Skeletally Immature Prepubescent Children.

Anterior cruciate ligament (ACL) tears are occurring in youth athletes with increasing frequency. Many ACL reconstruction procedures designed to allow for continued growth in patients with open physes have been described, but large series with mid- to long-term outcomes data are lacking. The purpose of the current study was to assess the clinical outcomes of a large cohort of prepubescent children who underwent a physeal-sparing, combined intra- and extra-articular ACL reconstruction with iliotibial (IT) band autograft over a 23-year period. Included in our analysis were 237 patients (240 knees) who underwent ACL reconstruction using IT band autograft at Tanner stage 1 or 2 (mean age of 11.2 ± 1.7 years). Physical examination data were analyzed for 225 of the 240 knees (mean follow-up, 25.8 months), and 137 (57%) of the knees had corresponding patient-reported clinical outcomes (patient-reported graft rupture and Pediatric International Knee Documentation Committee [Pedi-IKDC], Tegner activity scale, and Lysholm scores; mean follow-up, 6.2 years). Rates of growth arrest, IT band graft-harvest morbidity, and return to sports were analyzed. Physical examination revealed that 96.8% of the knees were grade A on the Lachman test and 98.8% were grade A on the pivot-shift test. Graft rupture occurred in 9 (6.6%) of 137 knees, at an average of 33.5 months (range, 8.2 months to 8.0 years) postoperatively. For patients who did not sustain a graft rupture, the mean Pedi-IKDC score was 93.3 ± 11.0, the mean Lysholm score was 93.4 ± 9.9, and the mean score on the Tegner activity scale was 7.8 (mode, 7). While lateral thigh asymmetry at the IT band harvest site was noted by 48% of the subjects, only 1.6% reported associated pain. No cases of limb-length discrepancy or angular deformity were observed. This procedure was associated with excellent functional outcomes, minimal risk of growth disturbance, and a low graft-rupture rate in skeletally immature prepubescent children. These results appear durable at mid- to long-term follow-up, at an average of >6 years postoperatively. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.