Improved Diagnostic Accuracy of Thyroid Fine-Needle Aspiration Cytology with Artificial Intelligence Technology.

Background: Artificial intelligence (AI) is increasingly being applied in pathology and cytology, showing promising results. We collected a large dataset of whole slide images (WSIs) of thyroid fine-needle aspiration cytology (FNA), incorporating z-stacking, from institutions across the nation to develop an AI model. Methods: We conducted a multicenter retrospective diagnostic accuracy study using thyroid FNA dataset from the Open AI Dataset Project that consists of digitalized images samples collected from 3 university hospitals and 215 Korean institutions through extensive quality check during the case selection, scanning, labeling, and reviewing process. Multiple z-layer images were captured using three different scanners and image patches were extracted from WSIs and resized after focus fusion and color normalization. We pretested six AI models, determining Inception ResNet v2 as the best model using a subset of dataset, and subsequently tested the final model with total datasets. Additionally, we compared the performance of AI and cytopathologists using randomly selected 1031 image patches and reevaluated the cytopathologists' performance after reference to AI results. Results: A total of 10,332 image patches from 306 thyroid FNAs, comprising 78 malignant (papillary thyroid carcinoma) and 228 benign from 86 institutions were used for the AI training. Inception ResNet v2 achieved highest accuracy of 99.7%, 97.7%, and 94.9% for training, validation, and test dataset, respectively (sensitivity 99.9%, 99.6%, and 100% and specificity 99.6%, 96.4%, and 90.4% for training, validation, and test dataset, respectively). In the comparison between AI and human, AI model showed higher accuracy and specificity than the average expert cytopathologists beyond the two-standard deviation (accuracy 99.71% [95% confidence interval (CI), 99.38-100.00%] vs. 88.91% [95% CI, 86.99-90.83%], sensitivity 99.81% [95% CI, 99.54-100.00%] vs. 87.26% [95% CI, 85.22-89.30%], and specificity 99.61% [95% CI, 99.23-99.99%] vs. 90.58% [95% CI, 88.80-92.36%]). Moreover, after referring to the AI results, the performance of all the experts (accuracy 96%, 95%, and 96%, respectively) and the diagnostic agreement (from 0.64 to 0.84) increased. Conclusions: These results suggest that the application of AI technology to thyroid FNA cytology may improve the diagnostic accuracy as well as intra- and inter-observer variability among pathologists. Further confirmatory research is needed.

A Nationwide Study on HER2-low Breast Cancer in South Korea: Its Incidence of 2022 Real World Data and the Importance of Immunohistochemical Staining Protocols.

Purpose: Notable effectiveness of trastuzumab deruxtecan (T-DXd) in patients with HER2-low advanced breast cancer (BC) has focused pathologists' attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. Materials and Methods: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. Results: Total 11,416 patients from twenty-five institutions included in this study. Of these patients, 40.7% (range: 6.0%-76.3%) were classified as HER2-zero, 41.7% (range: 10.5%-69.1%) as HER2-low, and 17.5% (range: 6.7%-34.0%) as HER2-positive. HER2-low tumors were associated with positive ER and PR statuses (p<0.001 and p<0.001, respectively). Antigen retrieval times (≥ 36 min vs. < 36 min) and antibody incubation times (≥ 12 min vs. < 12 min) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy (CNB) and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3259) of the patients. Conclusion: The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Deep Learning-Based Computational Cytopathologic Diagnosis of Metastatic Breast Carcinoma in Pleural Fluid.

A Pleural effusion cytology is vital for treating metastatic breast cancer; however, concerns have arisen regarding the low accuracy and inter-observer variability in cytologic diagnosis. Although artificial intelligence-based image analysis has shown promise in cytopathology research, its application in diagnosing breast cancer in pleural fluid remains unexplored. To overcome these limitations, we evaluate the diagnostic accuracy of an artificial intelligence-based model using a large collection of cytopathological slides, to detect the malignant pleural effusion cytology associated with breast cancer. This study includes a total of 569 cytological slides of malignant pleural effusion of metastatic breast cancer from various institutions. We extracted 34,221 augmented image patches from whole-slide images and trained and validated a deep convolutional neural network model (DCNN) (Inception-ResNet-V2) with the images. Using this model, we classified 845 randomly selected patches, which were reviewed by three pathologists to compare their accuracy. The DCNN model outperforms the pathologists by demonstrating higher accuracy, sensitivity, and specificity compared to the pathologists (81.1% vs. 68.7%, 95.0% vs. 72.5%, and 98.6% vs. 88.9%, respectively). The pathologists reviewed the discordant cases of DCNN. After re-examination, the average accuracy, sensitivity, and specificity of the pathologists improved to 87.9, 80.2, and 95.7%, respectively. This study shows that DCNN can accurately diagnose malignant pleural effusion cytology in breast cancer and has the potential to support pathologists.

Current state of cytopathology residency training: a Korean national survey of pathologists.

BACKGROUND: Although the Korean Society for Cytopathology has developed educational goals as guidelines for cytopathology education in Korea, there is still no systematic approach to cytopathology education status for pathology residents. Furthermore, satisfaction with cytopathology education and with the outcome of the current training/educational program has not been investigated in Korea. This study aimed to obtain comprehensive data on the current state of cytopathology education for residents and evaluate education outcomes. METHODS: An online survey was conducted in December 2020 for the board-certified pathologists and training residents registered as members of the Korean Society for Cytopathology. The questionnaire comprised questions that investigated the current status of cytopathology at each training institution, the degree of satisfaction with the work and education related to cytopathology, outcomes of cytopathology training, and educational accomplishments. RESULTS: Of the participants surveyed, 12.3% (132/1,075) completed the questionnaire, and 36.8% (32/87) of cytopathology residents participated. The mean overall satisfaction with cytopathology education was 3.1 points (on a 1- to 5-point scale, 5: very satisfied). The most frequent suggestion among the free description format responses was to expand educational opportunities, such as online education opportunities, outside of the individual institutions. CONCLUSIONS: Our results showed that cytopathology training in Korea needs further improvement. We expect that this study will inform systematic training of competent medical personnel armed with broad cytopathology knowledge and strong problem-solving abilities.

Fabrication of Piezo-Resistance Composites Containing Thermoplastic Polyurethane/Hybrid Filler Using 3D Printing.

In this study, 3D-printable flexible piezoresistive composites containing various amounts of cilia-like hybrid fillers were developed. In the hybrid fillers, micro-scale Cu particles with a 0D structure may allow them to easily disperse into the flexible TPU matrix. Furthermore, nanoscale multi-walled carbon nanotubes (MWCNTs) with a high aspect ratio, present on the surface of the Cu particles, form an electrical network when the polymer matrix is strained, thus providing good piezoresistive performance as well as good flowability of the composite materials. With an optimal hybrid filler content (17.5 vol.%), the 3D-printed piezoresistive composite exhibits a gauge factor of 6.04, strain range of over 20%, and durability of over 100 cycles. These results highlight the potential applications of piezoresistive pressure sensors for health monitoring, touch sensors, and electronic skin.

[Evaluation of Post-Neoadjuvant Chemotherapy Pathologic Complete Response and Residual Tumor Size of Breast Cancer: Analysis on Accuracy of MRI and Affecting Factors]. / ì‹ ë³´ê°•í™”í•™ìš”ë²• 후 ìœ ë°©ì•”ì˜ ë³‘ë¦¬í•™ì  ì™„ì „ 관해 예측 및 잔류 암 평가: ìœ ë°©ìžê¸°ê³µëª ì˜ìƒì˜ ì •í™•ë„ 및 영향인자 분석.

Purpose: To evaluate the accuracy of MRI in predicting the pathological complete response (pCR) and the residual tumor size of breast cancer after neoadjucant chemotherapy (NAC), and to determine the factors affecting the accuarcy. Materials and Methods: Eighty-eight breast cancer patients who underwent surgery after NAC at our center between 2010 and 2017 were included in this study. pCR was defined as the absence of invasive cancer on pathological evaluation. The maximum diameter of the residual tumor on post-NAC MRI was compared with the tumor size of the surgical specimen measured pathologically. Statistical analysis was performed to elucidate the factors affecting pCR and the residual tumor size-discrepancy between the MRI and the pathological measurements. Results: The pCR rate was 10%. The diagnostic accuracy of MRI and the area under the curve for predicting pCR were 90.91% and 0.8017, respectively. The residual tumor sizes obtained using MRI and pathological measurements showed a strong correlation (r = 0.9, p < 0.001), especially in patients with a single mass lesion (p = 0.047). The size discrepancy between MRI and the pathological measurements was significantly greater in patients with the luminal type (p = 0.023) and multifocal tumors/non-mass enhancement on pre-NAC MRI (p = 0.047). Conclusion: MRI is an accurate tool for evaluating pCR and residual tumor size in breast cancer patients who receive NAC. Tumor subtype and initial MRI features affect the accuracy of MRI.

Recent Developments towards Commercialization of Metal Matrix Composites.

Metal matrix composites (MMCs) are promising alternatives to metallic alloys. Their high strength-to-weight ratios; high temperature stabilities; and unique thermal, electrical, and chemical properties make them suitable for automotive, aerospace, defense, electrical, electronic, energy, biomedical, and other applications. The wide range of potential combinations of materials allows the properties of MMCs to be tailored by manipulating the morphology, size, orientation, and fraction of reinforcement, offering further opportunities for a variety of applications in daily life. This Special Issue, "Metal Matrix Composites", addresses advances in the material science, processing, material modeling and characterization, performance, and testing of metal matrix composites.

Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites-Part 2: Effect of Nitrogen Flow Rates and Processing Temperatures.

The nitridation-induced self-formed aluminum matrix composite (NISFAC) process is based on the nitridation reaction, which can be significantly influenced by the characteristics of the starting materials (e.g., the chemical composition of the aluminum powder and the type, size, and volume fraction of the ceramic reinforcement) and the processing variables (e.g., process temperature and time, and flow rate of nitrogen gas). Since these variables do not independently affect the nitridation behavior, a systematic study is necessary to examine the combined effect of these variables upon nitridation. In this second part of our two-part report, we examine the effect of nitrogen flow rates and processing temperatures upon the degree of nitridation which, in turn, determines the amount of exothermic reaction and the amount of molten Al in the nitridation-induced self-formed aluminum matrix composite (NISFAC) process. When either the nitrogen flow rate or the set temperature was too low, high-quality composites were not obtained because the level of nitridation was insufficient to fill the powder voids with molten Al. Hence, since the filling of the voids in the powder bed by molten Al is essential to the NISFAC process, the conditions should be optimized by manipulating the nitrogen flow rate and processing temperature.

Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites-Part 1: Effect of Reinforcement Volume Fraction, Size, and Processing Temperatures.

This paper investigates the effect of the size and volume fraction of SiC, along with that of the processing temperature, upon the nitridation behavior of aluminum powder during the nitridation-induced self-formed aluminum composite (NISFAC) process. In this new composite manufacturing process, aluminum powder and ceramic reinforcement mixtures are heated in nitrogen gas, thus allowing the exothermic nitridation reaction to partially melt the aluminum powder in order to assist the composite densification and improve the wetting between the aluminum and the ceramic. The formation of a sufficient amount of molten aluminum is key to producing sound, pore-free aluminum matrix composites (AMCs); hence, the degree of nitridation is a key factor. It was demonstrated that the degree of nitridation increases with decreasing SiC particle size and increasing SiC volume fraction, thus suggesting that the SiC surface may act as an effective pathway for nitrogen gas diffusion. Furthermore, it was found that effective nitridation occurs only at an optimal processing temperature. When the degree of nitridation is insufficient, molten Al is unable to fill the voids in the powder bed, leading to the formation of low-quality composites with high porosities. However, excessive nitridation is found to rapidly consume the nitrogen gas, leading to a rapid drop in the pressure in the crucible and exposing the remaining aluminum powder in the upper part of the powder bed. The nitridation behavior is not affected by these variables acting independently; therefore, a systematic study is needed in order to examine the concerted effect of these variables so as to determine the optimal conditions to produce AMCs with desirable properties for target applications.

Expression patterns of programmed death-1 and programmed death-1 ligand-1 on T cells in gastric cancer.

The aim of the present study was to evaluate programmed death-1 (PD-1) and programmed death-1 ligand-1 (PD-L1) expression in gastric carcinoma and to assess their effect on survival rate. A total of 170 surgically resected specimens were obtained from patients diagnosed with gastric carcinoma at St. Vincents Hospital, The Catholic University of Korea. Paraffin tissue sections from tissue microarray blocks were subjected to immunohistochemical analysis of PD-1 and PD-L1. In addition, PD-1 expression on CD4+ and CD8+ T cells isolated from peripheral blood mononuclear cells and gastric cancer tissues was evaluated by multicolor flow cytometry. PD-1 and PD-L1 were expressed in 30.0 and 60.5% of the gastric cancer tissues, respectively. The expression of PD-L1 was higher in patients with advanced T (P=0.035) and Tumor, Node and Metastasis stage (P=0.05). The patients with positive PD-L1 expression had shorter disease-free survival time than those without PD-L1 expression (P=0.005). Additionally, PD-L1 expression was significantly associated with poor prognosis (P=0.015). PD-1 and PD-L1 expression levels were significantly higher on CD8+ T cells than on CD4+ T cells (P<0.001). The data of the present study suggested that PD-L1 expression may be an independent indicator of poor prognosis in patients with gastric cancer. Furthermore, PD-L1 expression may play a role in immune evasion of gastric cancer.

High expression level of SOX2 is significantly associated with shorter survival in patients with thymic epithelial tumors.

OBJECTIVES: Thymic epithelial tumors (TET) are heterogenous tumors which are composed of thymoma (TM) and thymic carcinoma (TC). We attempted to determine differences in gene expression between TM and TC, and to determine the effect of such genes on the prognosis of patients with TET. MATERIALS AND METHODS: Gene expression profiles of SOX2, OCT-4, IGF-1, IGF-1R and IR mRNA transcripts in tumor tissues of TM and TC were determined using real-time PCR (RT-PCR). We constructed tissue microarray with 140 paraffin-embedded tumor tissues and performed immunohistochemistry (IHC) for IGF-1R-related signaling molecules, including SOX2, IGF-1, IGF-1R and pAKT. RESULTS: SOX2 mRNA expression was notably higher (216-fold) in TCs than in TMs. However, there was no significant difference in expression of IGF-1, IGF-1R, OCT-4 or IR between the two tumor types. In IHC results, SOX2 (HR: 7.57, P = 0.001) and IGF-1 (HR: 9.43, P = 0.001) expression levels in TC were significantly higher than those in TM. There was a significant correlation in expression of SOX2 with IGF-1 (P = 0.021) and pAKT (P = 0.026). In univariate analysis, clinical TNM stage, WHO classification, serum LDH, expression of SOX2, IGF-1R, IGF-1 and pAKT, were significantly correlated with overall survival (OS). Multivariate analysis using a forward-selection procedure revealed that clinical N stage (HR: 4.08, P < 0.001), M stage (HR: 3.37, P = 0.001) and SOX2 expression (HR: 4.53, P = 0.010) were significantly associated with OS. CONCLUSIONS: SOX2 is expressed significantly higher in TC than in TM. SOX2 expression is also closely related to IGF-1 and pAKT expression. The higher expression of SOX2 is significantly associated with shorter survival in patients with TET.

Aluminum Matrix Composites Manufactured using Nitridation-Induced Self-Forming Process.

Conventional manufacturing processes for aluminum matrix composites (AMCs) involve complex procedures that require unique equipment and skills at each stage. This increases the process costs and limits the scope of potential applications. In this study, a simple and facile route for AMC manufacturing is developed, a mixture of Al powder and the ceramic reinforcement is simply heated under nitrogen atmosphere to produce the composite. During heating under nitrogen atmosphere, the surface modification of both Al and the reinforcement is induced by nitridation. When the oxide layer covering Al powder surface is transformed to nitrides, temperature in the local region increases rapidly, resulting in a partial melt of Al powder. The molten Al infiltrates into the empty space among Al powder and reinforcement, thereby enabling consolidation of powders without external forces. It is possible to fabricate AMCs with various types, sizes, volume fractions, and morphologies of the reinforcement. Furthermore, the manufacturing temperature can be lowered below the melting point of Al (or the solidus temperature for alloys) because of the exothermic nature of the nitridation, which prevents formation of un-wanted reactants. The relative simplicity of this process will not only provide sufficient price competitiveness for the final products but also contribute to the expansion of the application scope of AMCs.

Loss of Human Leukocyte Antigen Class I Expression Is Associated with Poor Prognosis in Patients with Advanced Breast Cancer.

BACKGROUND: Human leukocyte antigen class I (HLA-I) molecules play important roles in regulating immune responses. Loss or reduction of HLA-I expression has been shown to be associated with prognosis in several cancers. Regulatory T-cells (Tregs) also play critical functions in immune response regulation. Evaluation of HLA-I expression status by the EMR8-5 antibody and its clinical impact in breast cancer have not been well studied, and its relationship with Tregs remains unclear. METHODS: We evaluated HLA-I expression and Treg infiltration by immunohistochemistry in 465 surgically resected breast cancer samples. We examined the correlation between HLA-I expression and Treg infiltration and clinicopathologic characteristics and survival analyses were performed. RESULTS: Total loss of HLA-I expression was found in 84 breast cancer samples (18.1%). Univariate survival analysis revealed that loss of HLA-I expression was significantly associated with worse disease-specific survival (DSS) (p = .029). HLA-I was not an independent prognostic factor in the entire patient group, but it was an adverse independent prognostic factor for DSS in patients with advanced disease (stage II-IV) (p = .031). Treg numbers were significantly higher in the intratumoral stroma of HLA-I-positive tumors than in HLA-I-negative tumors (median 6.3 cells/high power field vs 2.1 cells/high power field, p < .001). However, Tregs were not an independent prognostic factor in our cohort. CONCLUSIONS: Our findings suggest that the loss of HLA-I expression is associated with poor prognosis in breast cancer patients, highlighting the role of HLA-I alterations in immune evasion mechanisms of breast cancer. HLA-I could be a promising marker that enables the application of more effective and precise immunotherapies for patients with advanced breast cancer.

Prognostic value of systemic inflammatory markers and development of a nomogram in breast cancer.

Systemic inflammatory markers derived from peripheral blood cell, such as the neutrophil-lymphocyte ratio (NLR), derived neutrophil-lymphocyte ratio (dNLR), platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR), have been demonstrated as prognostic markers in several types of malignancy. Here, we investigated and compared the association between systemic inflammatory markers and survival and developed a prognostic nomogram in breast cancer patients. We reviewed the clinical and pathological records of 661 patients diagnosed with invasive breast carcinoma between 1993 and 2011. The NLR, dNLR, PLR and LMR in the immediate preoperative period were assessed. We analyzed the relationship between these inflammatory markers and clinicopathologic variables, disease-specific survival (DSS), and disease-free survival (DFS) in patients. A nomogram was developed to predict 3- and 5-year DSS for breast cancer. In the univariate analysis, high NLR, dNLR, PLR and low LMR were all significantly associated with poor DSS and DFS. In the multivariate analysis, only the PLR (HR 3.226, 95% CI 1.768-5.885 for DSS and HR 1.824, 95% CI 1.824-6.321 for DFS) was still identified as an independent predictor of outcomes. A subgroup analysis revealed that the PLR was the sole independent marker predicting poor DSS in patients with lymph node metastasis (HR 2.294, 95% CI 1.102-4.777) and with luminal subtype (HR 4.039, 95% CI 1.905-8.562). The proposed nomogram, which includes the PLR, shows good accuracy in predicting DSS with a concordance index of 0.82. PLR is an indicator of systemic inflammation as a part of the host immune response. As an independent prognostic factor, an elevated preoperative PLR is superior to the NLR, dNLR, and LMR in predicting clinical outcomes in patients with breast cancer. Moreover, the nomogram incorporating the PLR could accurately predict individualized survival probability in breast cancer.

Use of the Ion AmpliSeq Cancer Hotspot Panel in clinical molecular pathology laboratories for analysis of solid tumours: With emphasis on validation with relevant single molecular pathology tests and the Oncomine Focus Assay.

Targeted application of next-generation sequencing (NGS) technology allows detection of specific mutations that can provide treatment opportunities for cancer patients. We evaluated the applicability of the Ion AmpliSeq Cancer Hotspot Panel V2 (CHV2) using formalin-fixed, paraffin-embedded (FFPE) tissue of clinical specimens. Thirty-five FFPE tumour samples with known mutational status were collected from four different hospitals and sequenced with CHV2 using an Ion Chef System and Ion S5 XL system. Out of 35 cases, seven were sequenced with Oncomine focus Assay Panel for comparison. For the limit of detection test, we used an FFPE reference standard, a cell line that included an engineered 50% EGFR T790 M in an RKO cell line background. Coverage analysis results including number of mapped reads, on target percent, mean depth, and uniformity were not different according to hospitals. Sensitivity for mutation detection down to 3% was demonstrated. NGS results showed 100% concordance with the results from single molecular pathology tests Assay in 30 cases with 24 known positive mutations and 14 known negative mutations, and another NGS panel of the Oncomine focus in seven cases. The CHV2 NGS test for solid tumours using Ion chef system and S5 XL system in clinical molecular pathology laboratories for analysis of solid tumours could be routinely used and could replace some single molecular pathology tests after a stringent and thorough validation process.

Application of adipocyte-related antibodies in undifferentiated sarcomas to identify dedifferentiated liposarcomas based on histological and clinical analysis.

BACKGROUND: Due to morphologic similarities between undifferentiated sarcoma (US) and dedifferentiated liposarcoma (DDLPS), some portions of US could be identified as DDLPS. In this study, we applied adipocyte-related antibodies in order to discriminate possible cases of DDLPS from US. MATERIALS AND METHODS: A total of 46 cases, previously diagnosed as US, were examined. Immunohistochemistry for MDM2, CDK4, calreticulin, FABP4, and stathmin were performed. Histological findings were reviewed and clinical data was analyzed retrospectively. RESULTS: MDM2, CDK4, calreticulin, FABP4, and stathmin were positive in 17 (37.0%), 14 (30.4%), 3 (6.5%), 1 (2.2%), and 12 (26.1%) of the total 46 cases, respectively. MDM2/CDK4 positive cases showed more frequent positivity for calreticulin/FABP4/stathmin. Survival analysis, based on staining pattern, revealed a significantly better survival in the group where either MDM2 and CDK4 were positive and at least one of calreticulin, FABP4, or stathmin staining were positive. CONCLUSIONS: We conclude that when either MDM2-positive or CDK4-positive cases show any other positive results for calreticulin, FABP4, or stathmin, they have a significantly better survival and the possibility of DDLPS should be considered. Additional use of calreticulin, FABP4, or stathmin immunohistochemistry helps us to narrow the pool for further studies such as molecular analysis for a definite diagnosis.

Control of terahertz nonlinear transmission with electrically gated graphene metadevices.

Graphene, which is a two-dimensional crystal of carbon atoms arranged in a hexagonal lattice, has attracted a great amount of attention due to its outstanding mechanical, thermal and electronic properties. Moreover, graphene shows an exceptionally strong tunable light-matter interaction that depends on the Fermi level - a function of chemical doping and external gate voltage - and the electromagnetic resonance provided by intentionally engineered structures. In the optical regime, the nonlinearities of graphene originated from the Pauli blocking have already been exploited for mode-locking device applications in ultrafast laser technology, whereas nonlinearities in the terahertz regime, which arise from a reduction in conductivity due to carrier heating, have only recently been confirmed experimentally. Here, we investigated two key factors for controlling nonlinear interactions of graphene with an intense terahertz field. The induced transparencies of graphene can be controlled effectively by engineering meta-atoms and/or changing the number of charge carriers through electrical gating. Additionally, nonlinear phase changes of the transmitted terahertz field can be observed by introducing the resonances of the meta-atoms.

Florid cystic endosalpingiosis associated with a retroperitoneal leiomyoma mimicking malignancy: a case report.

Florid cystic endosalpingiosis (FCE) is a rare type of endosalpingiosis that presents as a mass-like lesion. Here we report an unusual case of FCE associated with a retroperitoneal leiomyoma. A 46-year old female presented with a palpable abdominal mass. A pelvic CT revealed a 23.5×16.3×9.4 cm sized multilocular cystic and solid mass in the retroperitoneum. Surgical excision of the mass was performed. Microscopically, the cystic spaces were lined by a single layer of ciliated tubal epithelium. The solid areas consisted of thick bundles of spindle cells. There were no cytologic atypia, mitosis or necrosis. The spindle cells were positive for actin and desmin, and were negative for c-kit, CD34, S100 and HMB-45, confirming the diagnosis of FCE associated with retroperitoneal leiomyoma.