Histological Classification Criteria Research Articles

A dense connection encoding–decoding convolutional neural network structure for semantic segmentation of thymoma

Accurately positioning and segmenting thymoma from computed tomography (CT) images is of great importance for an image-driven thymoma analysis. In clinical practice, the diagnosis and segmentation of thymomas for radiologists are time-consuming and inefficient tasks. Thus, it is necessary to develop a method to accurately and efficiently realize automatic segmentation of thymoma. Here, a dense skip connection encoding–decoding model (DSC-Net), which is a deep convolutional neural network, was proposed to perform automatic segmentation of thymoma with the ability to fuse feature maps under receptive fields of different scales. An image preprocessing method was also proposed to provide much more texture information and enhance the contrast between thymoma and its surrounding tissues. A total of 310 subjects who underwent contrast-enhanced CT scanning were included in this ethically-approved retrospective study. All of the CT slices were manually labeled by four experienced radiologists, and 80% of images were included in the training set and the rest were included in the testing set. The performance of segmentation was evaluated by calculating the accuracy, intersection over union (IoU), and Boundary F1 contour matching score (BFScore) between the predicted segmentation and the manual labels. For segmentation of thymoma in the testing set, the accuracy, IoU and BFScore were 92.96%, 87.86% and 0.9087 respectively. Compared to the U-Net method, the DSC-Net model improved IoU by 3.94%. In addition, the efficacy and robustness of DSC-Net in segmentation of different patients and different types of thymoma classified by the WHO histological classification criteria were verified. The proposed preprocessing method and DSC-Net demonstrated improved performance in segmentation of thymomas, suggesting the ability to provide consistent delineation and assist radiologists in their clinical applications.

Odontogenic tumors and odontogenic cysts: a clinical and pathological analysis of 4 181 cases

Objective: To investigate the incidence and constituent ratio of odontogenic tumors or odontogenic cysts in School and Hospital of Stomatology, Jilin University and to provide the reference for the clinical treatment. Methods: According to the WHO 2017 histological classification criteria, the pathological data of 4181 patients diagnosed as odontogenic tumors or odontogenic cysts in the Department of Pathology, Jilin University Stomatological Hospital from January 1961 to December 2017 were collected. Statistical analysis of the pathological types, gender, age and location of various tumors and cysts was conducted. Results: Of 4 181 cases, 1 055 were tumors and 3 126 were cysts. Among odontogenic tumors, benign tumors accounted for 96.11% (1 014/1 055), and malignant tumors accounted for 3.89% (41/1 055). The most common pathological type of odontogenic tumors was ameloblastoma [53.27% (562/1 055)], followed by cemento-ossifying fibroma [21.23% (224/1 055)] and odontoma [12.99% (137/1 055)]. The male-female ratio was 1∶1.04. The high-risk ages were 10-39. Maxilla-mandible ratio was 1∶2.85.As for cysts, radicular cysts [50.45% (1 577/3 126)] was the most common pathological type, followed by odontogenic keratocyst [25.59% (800/3 126)] and dentigerous cysts [21.56% (674/3 126)]. The male-female ratio was 1.37∶1. The high-risk ages were 20-49. Maxilla-mandible ratio was 1.37∶1. Conclusions: There was no gender preference for odontogenic tumors in Jilin Province area in the 57 years. The majority tumors occurred in the radicular. The most common pathological type was ameloblastoma. As for odontogenic cysts, males showed a higher incidence and the majority cysts occurred in the maxilla. The most common pathological type was radicular cysts.

Influence of examiners' experience on the reproducibility of different gold standard techniques and histological criteria for validation of the diagnosis of occlusal caries lesions.

The aims of this study were to evaluate the influence (1) of the examiner experience and (2) three histological classification criteria on the reproducibility of two gold standard techniques (non-dye or dye) for validation of the diagnosis of occlusal caries. This study comprised a sample of 210 digital images of 105 permanent teeth (105 rhodamine B dyed and 105 dye-free hemisections) and six examiners. Images were evaluated on a laptop computer and categorised according to three different histological classification criteria (proposed by Ekstrand, Lussi or Downer) and repeated in order to allow reproducibility calculation. For data analysis, the six participants were divided into two groups: G1: examiners with previous experience in histological evaluation and G2: examiners with no experience in histological evaluation. Statistical significance was set at 0.05. Results: The mean intra-examiner reproducibility values in G1 were higher than G2 in all variables. Intra-examiner reproducibility was lower for the dye-free technique in both groups. The mean values of inter-examiner reproducibility in G1 ranged from 0.60 to 0.68, and in G2 values ranged from 0.34 to 0.69. Conclusion: It can be concluded that: (1) the examiners' experience seems to influence the reproducibility of the two gold standard techniques studied and reproducibility tends to be lower when the dye-free technique is used, and (2) the histological classification criterion does not appear to influence the reproducibility for validation of the diagnosis of occlusal caries.

Inter-observer variability of the histological classification of lupus glomerulonephritis in children

Background The gold standard for the classification of lupus nephritis (LN) is based on renal histology but variation in interpretation exists. The aim of this multicentric international study was to assess the inter-observer variability of the 2003 International Society Nephrology/Royal Pathology Society (ISN/RPS) LN histological classification criteria in children. Methods Expert histopathologists from a reference centre (USA) and three tertiary paediatric centres (UK) independently scored digitalized histology slides from percutaneous kidney biopsies of 55 children with LN. Histological ISN/RPS Class and additional features [LN-activity (scored 0–24), LN-chronicity (0–12), and tubulo-interstitial activity (TIA: 0–21)] were scored. Statistical analysis (Kappa score and intra-class correlation, ICC) quantified the level of agreement, interpreted as: 0.01–0.20 slight; 0.21–0.40 fair; 0.41–0.60 moderate; 0.61–0.80 good; 0.81–1.00 excellent agreement. Results In the cohort (73% females), the mean ± standard error (SE) age at the time of biopsy was 15.5 ± 0.39 years. Based on the reference centre, 42% (23/55) had ISN/RPS class IV with a LN-activity score of 4.23 ± 0.50, LN-chronicity 1.81 ± 0.18, and TIA 4.45 ± 0.35. There were between 4–54 (mean 16.7) glomeruli per biopsy. Pathologists had only fair agreement for LN ISN/RPS assignment (kappa 0.26 ± 0.12). LN-chronicity and TIA scoring were also only fair (ICC 0.36 ± 0.09 and 0.22 ± 0.09 respectively). Conversely, there was good agreement for scoring LN-activity features (ICC 0.69 ± 0.06). When the biopsy findings were categorized into proliferative and non-proliferative disease, poor agreement remained (kappa 0.24 ± 0.11). Conclusion Despite unified criteria for the interpretation of histological features of LN, marked reporting variation remains and this may influence treatment decisions. Adding activity features to the biopsy report improves inter-observer agreement. Supplementary measures of predicting the extent of LN, such as the use of non-invasive urine biomarkers, are required.

Inter-observer variability of the histological classification of lupus glomerulonephritis in children.

The gold standard for the classification of lupus nephritis is renal histology but reporting variation exists. The aim of this study was to assess the inter-observer variability of the 2003 International Society of Nephrology/Royal Pathology Society (ISN/RPS) lupus nephritis histological classification criteria in children. Histopathologists from a reference centre and three tertiary paediatric centres independently reviewed digitalized renal histology slides from 55 children with lupus nephritis. Histological ISN/RPS Class was assigned and features scored; lupus nephritis-activity [scored 0-24], lupus nephritis-chronicity [0-12] and tubulointerstitial activity [0-21]. In the cohort (73% females), the age at the time of biopsy was 15.5 ± 0.39 (mean ± standard error) years. Based on the reference centre, 42% (23/55) had ISN/RPS Class IV with lupus nephritis-activity score 4.23 ± 0.50, lupus nephritis-chronicity 1.81 ± 0.18 and tubulointerstitial activity 4.45 ± 0.35. There were 4-54 (mean 16.7) glomeruli per biopsy. Pathologists had fair agreement for ISN/RPS assignment (kappa; 0.26 ± 0.12), lupus nephritis-chronicity (intra-class correlation 0.36 ± 0.09) and tubulointerstitial activity (0.22 ± 0.09) scores. There was good agreement for lupus nephritis-activity scores (intra-class correlation 0.69 ± 0.06). When categorized into proliferative and non-proliferative disease, poor agreement among sites remained (kappa 0.24 ± 0.11). Despite unified criteria for the interpretation of histological features of lupus nephritis, marked reporting variation remains in clinical practice. As proliferative lupus nephritis is managed more intensively, this may influence renal outcomes.

1536P - Multicenter Institutional Experience of Surgically Resected Thymic Epithelial Tumors (TETS): an Observational Report on Behalf of F.O.N.I.C.A.P. (Forza Operativa Nazionale Interdisciplinare Contro Il Cancro Del Polmone)

ABSTRACT Purpose thymic epithelial tumors (TETs) are a rare neoplasms. Due to their rarity, large-scale prospective trials are lacking. The present retrospective multicenter analysis aimed to evaluate clinical outcome and clinical-pathological features of TETs after complete surgical resection and adjuvant treatments (Adj) such as chemotherapy (CHT) or radiotherapy (RT). Patients and methods Patients who underwent a complete surgical resections for TETs between 2000 and 2007 were reviewed. WHO histological classification criteria and Masaoka staging system were used. Adj were: anthracycline- and platin-based CHT, RT on irradiation fields covering the primary tumor bed. Overall survival (OS) was calculated from the date of diagnosis until patient death or last follow-up visit. Disease free-survival (DFS) was defined as the interval between surgery and date of first documentation of recurrence. OS, DFS and 95% Confidence Interval (95% CI) were estimated by Kaplan-Meier method. Results 62 patients were analyzed: 30 patients (48%) male and 32 (52%) female. Median age was 60 years (range: 33 - 86). At the beginning of their cancer history 20 (32%) patients had myasthenia. Clinical staging showed: 31 (50%) stage I disease, 19 (30%) stage II, 5 (8%) stage III, 2 (4%) stage IVa, 5 (8%) stage IVb. Histologies were: 11 (19%) A tumor type, 18 (29%) AB type, 7 (12%) B1 type, 11 (17%) B2 type, 11 (17%) B3 type and 3 (6%) C type. Pathological staging were: 30 (48%) stage I, 22 (35%) stage II, 3 (6%) stage III, 2 (3%) stage IVa, 5 (8%) stage IVb. 3 (5%) patients received Adj-CHT and 16 (26%) Adj-RT. Median follow-up was 71 months (range 1-145), DFS and OS are the following: % DFS (95% CI) % OS (95% CI) Events 48 mo 60 o0 72 mo Events 48 mo 60 mo 72 mo 9 89 (80-97) 89 (80-97) 86 (76-96) 7 97 (92-100) 95 (88-100) 92 (85-100) mo, months. Conclusions TETs are rare and indolent tumors. Surgery offers good results which can be further improved by Adj such as CHT and/or RT. Supported by GIPO. Disclosure All authors have declared no conflicts of interest.

Incidence patterns for primary malignant spinal cord gliomas: a Surveillance, Epidemiology, and End Results study.

Primary malignant spinal glioma represents a significant clinical challenge due to the devastating effect on clinical outcomes in the majority of cases. As they are infrequently encountered in any one center, there has been limited population-based data analysis on the incidence patterns of these aggressive tumors. The objective of this study was to use publically available Surveillance, Epidemiology and End Results (SEER) program data to examine the overall incidence and incidence patterns over time with regard to age at diagnosis, sex, race, primary site of tumor, and histological subtype in patients in whom primary malignant spinal cord gliomas were diagnosed between 1973 and 2006. The study population of interest was limited to primary, malignant, pathologically confirmed spinal cord gliomas based on data drawn from the SEER 9 standard registries for patients diagnosed between 1973 and 2006. Variables of interest included age at diagnosis, sex, race, primary site of tumor, and histological subtype of tumor. The SEER*Stat 6.5.2 program was used to calculate frequencies, age-adjusted incidence rates with 95% CIs, and annual percentage change (APC) statistics with a 2-sided p value. In addition, linear correlation coefficients (R(2)) were calculated for the time association stratified by variables of interest. The overall age-adjusted incidence rate for primary malignant spinal gliomas was 0.12 per 100,000, which increased significantly over the study period (APC = 1.74; p = 0.0004; R(2) = 0.36). The incidence was highest in patients diagnosed at ages 35-49 (0.17 per 100,000), males (0.14 per 100,000), whites (0.13 per 100,000), and those with ependymomas (0.07 per 100,000). Over the study period, the incidence of ependymomas increased significantly (APC = 3.17; p < 0.0001; R(2) = 0.58) as did the incidence of these tumors in whites (APC = 2.13; p = 0.0001) and for both males (APC = 1.90, p value < 0.0001) and females (APC = 1.60, p < 0.0001). The authors found no significant changes in the incidence over time by age of diagnosis. This study demonstrates an increasing overall incidence of primary, malignant spinal cord glioma over the past 3 decades. Notably, for ependymoma the incidence has increased, whereas the incidence of most other glioma subtypes remained stable. This may be due to improved diagnostic and surgical techniques, changes in histological classification criteria, and changes in neuropathology diagnostic criteria. Although primary, malignant spinal cord gliomas are rare, an improved understanding of the incidence will assist investigators and clinicians in planning potential studies and preparing for allocation of resources to care for these challenging patients.

Correlation of Nuclear Morphometric Features with Animal and Human World Health Organization International Histological Classifications of Canine Spontaneous Seminomas

The aim of this study was to correlate nuclear morphometric features with animal and human World Health Organization International Histological Classifications in canine seminomas. Twenty-three canine seminomas were classified, according to Animal World Health Organization International Histological Classification as intratubular, intratubular with signs of invasion, or diffuse and according to Human World Health Organization International Histological Classification criteria as spermatocytic and typical. The morphonuclear characteristics of tumors were quantitatively evaluated by means of digital cell image analyses of hematoxylin and eosin-stained nuclei. In particular, the mean nuclear area, mean nuclear perimeter, mean nuclear form factor, and their respective standard deviations were calculated. The relationship between the different variables and the tumor histologic types was assessed. On the basis of animal and human classification systems, statistically significant differences were observed only between intratubular seminomas with signs of invasion and the other two types and between spermatocytic and typical seminomas, respectively. In humans, it is well known that typical seminomas are more common and aggressive than spermatocytic ones. In our study, the canine seminomas classified as typical showed significantly larger and more variable nuclear area and perimeter than spermatocytic seminomas. These results support the opinion that most canine seminomas correspond to human spermatocytic seminomas and could explain the benign behavior of canine seminomas, which derive from a more differentiated type of germ cell.

Molecular pathogenesis of astrocytic tumours

Our current knowledge of the molecular pathogenesis of the diffuse adult astrocytic tumours is vast if compared to 20 years ago, yet we are far from understanding the details of this process at the molecular level and using such an understanding to logically and specifically treat patients' tumours. In other astrocytic tumours we have little or no knowledge of the molecular processes. This article will attempt to summarise the histological classification criteria and genetic data for all the astrocytic tumours. The current World Health Organisation classification lists six entities, some with subgroups. Common problems associated with the diagnosis of these tumours are outlined. While the molecular findings are not as yet used clinically, we are approaching a time when the histological investigation will have to be supplemented with molecular data to ensure the best choice of treatment for the patient and as an accurate indicator of prognosis.

A reassessment of histologic classification and an immunohistochemical study of 88 retinoblastomas. A special reference to the advent of bipolar-like cells.

Despite perpetual efforts of investigators, the histogenesis of retinoblastoma is still in dispute and histologic classification satisfactorily predictive of prognosis does not seem to be in use. The authors studied 88 cases of retinoblastoma clinicopathologically and immunohistochemically, paying special attention to the presence of a "bipolar-like cell" element that would be used as one of the criteria for the diagnosis of differentiated retinoblastoma. Twelve cases of retinoblastoma with the bipolar-like cell element in the absence of rosettes and 41 cases of the tumor with rosettes were classified as differentiated retinoblastomas. The other 35 cases without rosettes or bipolar-like cells were classified as undifferentiated tumors. Tumor cells forming rosettes usually had positive results for synaptophysin and neuron-specific enolase (NSE) and negative results for glial fibrillary acidic protein (GFAP) and S-100 protein; however, undifferentiated cells had negative results for these four antibodies. The bipolar-like cells had positive results for synaptophysin and NSE but negative results for GFAP and S-100 protein. Twelve tumors with bipolar-like cells that lacked rosettes showed no optic nerve invasion, and the patients had a significantly better prognosis (100% 5-year survival rate) than 35 patients with undifferentiated tumors (71% 5-year survival rate) (P < 0.01). The findings support a neuronal origin of the tumor and indicate that, not only the rosettes symbolizing the photoreceptor differentiation, but also other neuronal elements, such as bipolar-like cells, can be used as criteria for histologic classification of retinoblastoma.

Trends in the incidence of endometrioid and clear cell cancers of the ovary in the United States.

An increase in reported incidence of endometrioid and clear cell cancers of the ovary occurred in the United States during the 1970s, while no change occurred in the overall incidence of ovarian cancer. The authors can not rule out that this was due to a shift in the criteria for histologic classification or improved coding, although these seem unlikely to account entirely for the change. In the four areas where the trend for endometrioid and clear cell cancers of the ovary was examined, the per cent increases in their occurrence were correlated with the per cent increases in the occurrence of carcinoma of the uterine corpus. The concomitant trends and the biologic similarities between these histologic types of ovarian cancer and the uterine cancers suggest that common etiologic factors may be involved. The role of postmenopausal estrogen use in the etiology of ovarian cancer must be clarified by further epidemiologic studies, but such studies should take tumor histology into consideration.