DNA methylation patterns at and beyond the histological margin of early-stage invasive lung adenocarcinoma radiologically manifested as pure ground-glass opacity.

BACKGROUND: Early-stage lung cancers radiologically manifested as ground-glass opacities (GGOs) have been increasingly identified, among which pure GGO (pGGO) has a good prognosis after local resection. However, the optimal surgical margin is still under debate. Precancerous lesions exist in tumor-adjacent tissues beyond the histological margin. However, potential precancerous epigenetic variation patterns beyond the histological margin of pGGO are yet to be discovered and described. RESULTS: A genome-wide high-resolution DNA methylation analysis was performed on samples collected from 15 pGGO at tumor core (TC), tumor edge (TE), para-tumor tissues at the 5 mm, 10 mm, 15 mm, 20 mm beyond the tumor, and peripheral normal (PN) tissue. TC and TE were tested with the same genetic alterations, which were also observed in histologically normal tissue at 5 mm in two patients with lower mutation allele frequency. According to the difference of methylation profiles between PN samples, 2284 methylation haplotype blocks (MHBs), 1657 differentially methylated CpG sites (DMCs), and 713 differentially methylated regions (DMRs) were identified using reduced representation bisulfite sequencing (RRBS). Two different patterns of methylation markers were observed: Steep (S) markers sharply changed at 5 mm beyond the histological margin, and Gradual (G) markers changed gradually from TC to PN. S markers composed 86.2% of the tumor-related methylation markers, and G markers composed the other 13.8%. S-marker-associated genes enriched in GO terms that were related to the hallmarks of cancer, and G-markers-associated genes enriched in pathways of stem cell pluripotency and transcriptional misregulation in cancer. Significant difference in DNA methylation score was observed between peripheral normal tissue and tumor-adjacent tissues 5 mm further from the histological margin (p < 0.001 in MHB markers). DNA methylation score at and beyond 10 mm from histological margin is not significantly different from peripheral normal tissues (p > 0.05 in all markers). CONCLUSIONS: According to the methylation pattern observed in our study, it was implied that methylation alterations were not significantly different between tissues at or beyond P10 and distal normal tissues. This finding explained for the excellent prognosis from radical resections with surgical margins of more than 15 mm. The inclusion of epigenetic characteristics into surgical margin analysis may yield a more sensitive and accurate assessment of remnant cancerous and precancerous cells in the surgical margins.

Development and prognostic relevance of a histologic grading and staging system for alcohol-related liver disease.

BACKGROUND & AIMS: The SALVE Histopathology Group (SHG) developed and validated a grading and staging system for the clinical and full histological spectrum of alcohol-related liver disease (ALD) and evaluated its prognostic utility in a multinational cohort of 445 patients. METHODS: SALVE grade was described by semiquantitative scores for steatosis, activity (hepatocellular injury and lobular neutrophils) and cholestasis. The histological diagnosis of steatohepatitis due to ALD (histological ASH, hASH) was based on the presence of hepatocellular ballooning and lobular neutrophils. Fibrosis staging was adapted from the Clinical Research Network staging system for non-alcoholic fatty liver disease and the Laennec staging system and reflects the pattern and extent of ALD fibrosis. There are 7 SALVE fibrosis stages (SFS) ranging from no fibrosis to severe cirrhosis. RESULTS: Interobserver κ-value for each grading and staging parameter was >0.6. In the whole study cohort, long-term outcome was associated with activity grade and cholestasis, as well as cirrhosis with very broad septa (severe cirrhosis) (p <0.001 for all parameters). In decompensated ALD, adverse short-term outcome was associated with activity grade, hASH and cholestasis (p = 0.038, 0.012 and 0.001, respectively), whereas in compensated ALD, hASH and severe fibrosis/cirrhosis were associated with decompensation-free survival (p = 0.011 and 0.001, respectively). On multivariable analysis, severe cirrhosis emerged as an independent histological predictor of long-term survival in the whole study cohort. Severe cirrhosis and hASH were identified as independent predictors of short-term survival in decompensated ALD, and also as independent predictors of decompensation-free survival in compensated ALD. CONCLUSION: The SALVE grading and staging system is a reproducible and prognostically relevant method for the histological assessment of disease activity and fibrosis in ALD. LAY SUMMARY: Patients with alcohol-related liver disease (ALD) may undergo liver biopsy to assess disease severity. We developed a system to classify ALD under the microscope by grading ALD activity and staging the extent of liver scarring. We validated the prognostic performance of this system in 445 patients from 4 European centers.

Histological analyses of trucut liver biopsies from patients with noncirrhotic portal fibrosis and extra-hepatic portal vein obstruction.

BACKGROUND: Both noncirrhotic portal fibrosis (NCPF) and extrahepatic portal venous obstruction (EHPVO) are important causes of noncirrhotic portal hypertension (PH) in the Asian region. In this study, we analyzed the histopathological changes of liver needle-core biopsies from patients with NCPF and EHPVO. PATIENTS AND METHODS: The patients were diagnosed as per the Asia Pacific Association for the Study of Liver (APASL) criteria. Minimum adequacy criteria for liver core biopsies were defined, and finally, 69 liver biopsies from patients with NCPF and 100 liver biopsies from patients with EHPVO were analyzed. All histological parameters were predefined, and three experienced pathologists analyzed the biopsies after reaching consensus. Institute ethics committee clearance was taken. RESULTS: Although some histological features were overlapping, phlebosclerosis of intra-hepatic branches of the portal vein (PV), periportal aberrant vascular channels, remnant portal tracts, and hepatic fibrosis beyond the portal tracts without the formation of complete hepatic nodules (P < 0.001 for all) were common histological characteristics of NCPF on core-needle liver biopsies; while maintained lobular architecture, nonspecific dilatation of PV branches, absence of intra-hepatic PV phlebosclerosis, aberrant vascular channels, and significant fibrosis were characteristics of EHPVO. CONCLUSIONS: Despite the considerable histological overlap between NCPF and EHPVO, careful histological evaluation, supplemented by clinical features, radiological and biochemical findings can help in making a conclusive diagnosis. Patients with NCPF and EHPVO with clinical jaundice show transaminitis, high serum alkaline phosphatase level, more variceal bleed, and histological evidences of nodular regenerative hyperplasia.

Assessment of cardiac tumors by 18F-FDG PET/CT imaging: Histological correlation and clinical outcomes.

BACKGROUND: To evaluate the diagnostic value of 18F-FDG PET/CT in distinguishing benign versus malignant cardiac tumors as well as to assess its prognostic value. METHODS: We analyzed 38 patients with cardiac tumors who underwent 18F-FDG PET/CT and followed for median 8.5 ± 12.5 months. SUVmax and TBRmax (maximum tumor-to-background ratio) by receiver-operating characteristic (ROC) curve analysis were used to obtain threshold for the diagnosis of malignancy as defined by histology (n = 38). Survival was assessed and correlated with the dignity of the lesions and PET parameters. RESULTS: Optimal cut-off values indicating malignancy were as follows: SUVmax = 3.44, with 100% sensitivity and 92.9% specificity, and TBRmax = 1.55, with 95.8% sensitivity and 92.9% specificity. A significant difference of 18F-FDG uptake was observed between primary benign (n = 14, SUVmax = 2.35 ± 1.31, TBRmax = 1.05 ± 0.50) compared to primary malignant cardiac tumors (n = 11, SUVmax = 8.90 ± 4.23, TBRmax = 3.82 ± 1.44) as well as cardiac metastases and lymphoma (n = 13, SUVmax = 14.37 ± 8.05, TBRmax = 6.19 ±  3.38) (all P < .001). Survival rate was significantly lower in patients with malignant as compared to benign cardiac tumors (P < .05). Regression analysis revealed that the lesion dignity determined by the cut-off value of SUVmax was an independent predictor for death in patients with cardiac tumors (P < .05). CONCLUSION: 18F-FDG uptake in cardiac tumors can differentiate between benign and malignant cardiac tumors and predicts survival.

Reporting regression in primary cutaneous melanoma. Part 2: prognosis, evaluation and management.

The effect of histological regression on patient prognosis for primary cutaneous melanoma is controversial. Some authors hypothesize that regression indicates a robust systemic immune response and may decrease risk of metastasis. Others argue that histological regression calls into question a T0 diagnosis because there may have been an invasive component of the melanoma that is no longer visible but is still active. The literature to date does not suggest that histological regression is associated with increased risk of positive sentinel lymph node status, metastasis or increased risk of mortality. Thus, the presence of histological regression should not change patient staging, evaluation or management. The criteria used for reporting regression have varied dramatically across studies, and standardized reporting is needed to foster evidence-based practices in the future.

Impact of pre-analytical variables on deep learning accuracy in histopathology.

AIMS: Machine learning (ML) binary classification in diagnostic histopathology is an area of intense investigation. Several assumptions, including training image quality/format and the number of training images required, appear to be similar in many studies irrespective of the paucity of supporting evidence. We empirically compared training image file type, training set size, and two common convolutional neural networks (CNNs) using transfer learning (ResNet50 and SqueezeNet). METHODS AND RESULTS: Thirty haematoxylin and eosin (H&E)-stained slides with carcinoma or normal tissue from three tissue types (breast, colon, and prostate) were photographed, generating 3000 partially overlapping images (1000 per tissue type). These lossless Portable Networks Graphics (PNGs) images were converted to lossy Joint Photographic Experts Group (JPG) images. Tissue type-specific binary classification ML models were developed by the use of all PNG or JPG images, and repeated with a subset of 500, 200, 100, 50, 30 and 10 images. Eleven models were generated for each tissue type, at each quantity of training images, for each file type, and for each CNN, resulting in 924 models. Internal accuracies and generalisation accuracies were compared. There was no meaningful significant difference in accuracies between PNG and JPG models. Models trained with more images did not invariably perform better. ResNet50 typically outperformed SqueezeNet. Models were generalisable within a tissue type but not across tissue types. CONCLUSIONS: Lossy JPG images were not inferior to lossless PNG images in our models. Large numbers of unique H&E-stained slides were not required for training optimal ML models. This reinforces the need for an evidence-based approach to best practices for histopathological ML.

Carcinoma Seroso Papilar Peritoneal Primario: serie de casos Hospital Clínico Universidad de Chile 2010-2015 / Primary Serous Papillary Carcinoma: Case Report, Hospital Clinico Universidad de Chile 2010-2015

Los cánceres peritoneales primarios son una patología de baja prevalencia, dentro de los cuales el carcinoma seroso papilar primario de peritoneo es el más frecuente con una incidencia de 6,78 casos por millón de habitantes. Predomina en el sexo femenino y su principal diagnóstico diferencial es el carcinoma papilar seroso de ovario avanzado, para lo cual la inmunohistoquímica, junto a sus clasificaciones clínicas y anatomopatológicas son la forma de diferenciar en base a la clasificación de la Organización Mundial de la salud para lesiones tumorales. Objetivo: Describir los resultados inmuno-histoquímicos de una serie de casos estudiados en el Hospital Clinico de la Universidad de Chile y compararlos con la literatura médica. Material y Método: Estudio retrospectivo, descriptivo en base a análisis de 12 biopsias entre Enero 2010 y Marzo 2015 clasificándolos según edad, sexo y registro de biopsia. Se realizó técnica histológica rutinaria además de las tinciones inmunohistoquímicas para WT1, citoqueratinas y otros reactivos de acuerdo a los diagnósticos diferenciales. Resultados: La distribución etaria fue de 47 a los 75 años, media de 60 años, el 100% de los casos de sexo femenino. Los reactivos de Inmunohistoquímica predominantes fueron WT1 (53,8%), Citoqueratina-7 (38,5%). Conclusiones: Este carcinoma es una entidad poco común en la clínica, con similitudes al carcinoma seroso ovárico. Existe consenso sobre el diagnóstico de esta patología, el cual se debe orientar, según los criterios de la Gynecologic Oncology Group. Ante la sospecha clínica, el patólogo puede realizar el estudio inmunohistoquímico dirigido y así tener un diagnóstico preciso para determinar la conducta terapéutica del cirujano.

The primary peritoneal cancer is a low prevalence disease, within which primary papillary serous carcinoma of the peritoneum is the most frequent with an incidence of 6.78 cases per million inhabitants. Predominates in females and its main differential diagnosis is advanced ovarian papillary serous carcinoma, for which immunohistochemistry and clinical and pathological classifications are the way to differentiate base on the World Health Organization classification for tumor lesions. Objective: Describe the immunohistochemical results of a series of cases studied in Universidad de Chile Clinical Hospital and to compare them with the literature. Material and Methods: Descriptive retrospective study based on analysis of biopsies from 12 cases between January 2010 and March 2015 classifying them according to age, sex and biopsy register. Routine histological technique was performed in addition to the immunohistochemical staining for WT1, cytokeratin and other reagents according to the differential diagnoses. Results: The age distribution was 47 to 75 years, mean 60 years, 100% of cases female. Immunohistochemical reagents were predominant WT1 (53.8%) and cytokeratin-7 (38.5%). Conclusion: This carcinoma is a rare entity in routine clinical practice, with similarities to ovarian serous carcinoma.There is consensus on the diagnosis of this condition, which must be oriented according to the criteria of the Gynecologic Oncology Group. Clinical suspicion can lead the pathologist to perform immunohistochemical study and thus have an accurate diagnosis to determine the therapeutic approach of the surgeon.

Tests of association under misclassification: application to histological sampling in oncology.

Subjects in tumour studies are often misclassified with respect to histologic features that are not routinely recorded in diagnostic reports and that display heterogeneity within tumours. Pathologic analysis of the tumours may miss the feature of interest if the pathologist was not alerted to detail the microscopic feature of interest or if it is not present in the selected specimens. In this setting, only the subjects for whom the outcome is not found are potentially misclassified. Analyses of associations between the observed, potentially misclassified, outcome and a second outcome are invalid if the probability of misclassification depends on the second outcome. Three natural tests of association based on the observed data depend on different numbers of nuisance parameters. Most promising is a test based on the ratio of proportions of the observed feature. We illustrate this test using a study of the association of imaging parameters with genetic features in subjects with oligodendroglioma, a common brain tumour. In this study, calcification, a feature related to the imaging parameters, was potentially misclassified as not present.

Cytologic-histologic correlation of nongynecologic cytopathology cases: separation of determinate from indeterminate cytologic diagnoses for analysis and monitoring of laboratory performance.

Much of the literature on the quality-assurance aspect of cytologic-histologic correlation (CHC) has focused on gynecologic cytology. For nongynecologic cytopathology, the process is complicated by the use of determinate (positive for malignant cells, negative for malignant cells) and indeterminate (atypical, suspicious, or follicular lesion) diagnostic categories. Here, we illustrate our routine methodology for analyzing CHC data on nongynecologic cytopathology cases by separating determinate from indeterminate cases. A focused list of determinate and indeterminate cytopathology cases with surgical pathology correlation is generated each week. The determinate cases are ascertained as true positive (TP), true negative (TN), false positive (FP), or false negative (TN). The discrepant cases (FP and FN) are investigated to determine the cause (sampling, interpretation, or screening). For indeterminate cases, the surgical pathology outcome (benign, malignant) and suitability of the cytopathology category utilized are reviewed. For the focused period of 4 mo, sensitivity was 70% and specificity was 100%. The most common reason for false-negative diagnoses was a sampling problem in the cytologic specimen; there were no false-positive diagnoses. Malignant outcomes for follicular lesion, atypical, and suspicious diagnoses were 29%, 40%, and 76%, respectively. Data derived from regularly performed CHC are useful in reviewing the diagnostic performance of the laboratory.