Annotation protocol and crowdsourcing multiple instance learning classification of skin histological images: The CR-AI4SkIN dataset.

Digital Pathology (DP) has experienced a significant growth in recent years and has become an essential tool for diagnosing and prognosis of tumors. The availability of Whole Slide Images (WSIs) and the implementation of Deep Learning (DL) algorithms have paved the way for the appearance of Artificial Intelligence (AI) systems that support the diagnosis process. These systems require extensive and varied data for their training to be successful. However, creating labeled datasets in histopathology is laborious and time-consuming. We have developed a crowdsourcing-multiple instance labeling/learning protocol that is applied to the creation and use of the CR-AI4SkIN dataset.2 CR-AI4SkIN contains 271 WSIs of 7 Cutaneous Spindle Cell (CSC) neoplasms with expert and non-expert labels at region and WSI levels. It is the first dataset of these types of neoplasms made available. The regions selected by the experts are used to learn an automatic extractor of Regions of Interest (ROIs) from WSIs. To produce the embedding of each WSI, the representations of patches within the ROIs are obtained using a contrastive learning method, and then combined. Finally, they are fed to a Gaussian process-based crowdsourcing classifier, which utilizes the noisy non-expert WSI labels. We validate our crowdsourcing-multiple instance learning method in the CR-AI4SkIN dataset, addressing a binary classification problem (malign vs. benign). The proposed method obtains an F1 score of 0.7911 on the test set, outperforming three widely used aggregation methods for crowdsourcing tasks. Furthermore, our crowdsourcing method also outperforms the supervised model with expert labels on the test set (F1-score = 0.6035). The promising results support the proposed crowdsourcing multiple instance learning annotation protocol. It also validates the automatic extraction of interest regions and the use of contrastive embedding and Gaussian process classification to perform crowdsourcing classification tasks.

ProGleason-GAN: Conditional progressive growing GAN for prostatic cancer Gleason grade patch synthesis.

BACKGROUND AND OBJECTIVE: Prostate cancer is one of the most common diseases affecting men. The main diagnostic and prognostic reference tool is the Gleason scoring system. An expert pathologist assigns a Gleason grade to a sample of prostate tissue. As this process is very time-consuming, some artificial intelligence applications were developed to automatize it. The training process is often confronted with insufficient and unbalanced databases which affect the generalisability of the models. Therefore, the aim of this work is to develop a generative deep learning model capable of synthesising patches of any selected Gleason grade to perform data augmentation on unbalanced data and test the improvement of classification models. METHODOLOGY: The methodology proposed in this work consists of a conditional Progressive Growing GAN (ProGleason-GAN) capable of synthesising prostate histopathological tissue patches by selecting the desired Gleason Grade cancer pattern in the synthetic sample. The conditional Gleason Grade information is introduced into the model through the embedding layers, so there is no need to add a term to the Wasserstein loss function. We used minibatch standard deviation and pixel normalisation to improve the performance and stability of the training process. RESULTS: The reality assessment of the synthetic samples was performed with the Frechet Inception Distance (FID). We obtained an FID metric of 88.85 for non-cancerous patterns, 81.86 for GG3, 49.32 for GG4 and 108.69 for GG5 after post-processing stain normalisation. In addition, a group of expert pathologists was selected to perform an external validation of the proposed framework. Finally, the application of our proposed framework improved the classification results in SICAPv2 dataset, proving its effectiveness as a data augmentation method. CONCLUSIONS: ProGleason-GAN approach combined with a stain normalisation post-processing provides state-of-the-art results regarding Frechet's Inception Distance. This model can synthesise samples of non-cancerous patterns, GG3, GG4 or GG5. The inclusion of conditional information about the Gleason grade during the training process allows the model to select the cancerous pattern in a synthetic sample. The proposed framework can be used as a data augmentation method.

Corticotroph cell hyperplasia as a rare cause of ACTH-dependent Cushing syndrome.

OBJECTIVE: Our aim was to characterise a cohort of patients with Cushing's disease (CD) who did not present pituitary adenoma in magnetic resonance imaging (MRI), needing a catheterisation of the inferior petrosal sinus (CIPS), and to study the pathological findings of the pituitary gland in these subjects after transsphenoidal surgery in order to establish the aetiology of CD. Furthermore, we evaluated possible differences in the features of the diagnosis between hyperplasia and adenoma. SUBJECTS AND METHODS: We included 16 subjects. 17 CIPS were done. Hormonal parameters were measured using standard methods. A microscopic histochemical study following standard procedures and immunohistochemical analysis was performed. The diagnostic criteria for adenoma and hyperplasia were based on the WHO classification. RESULTS: One patient was excluded for presenting an ACTH-producing bronchial neuroendocrine tumour. The 15 subjects with CD have a positive CIPS test indicating hypophyseal ACTH production. After transsphenoidal surgery, 12 patients showed a microadenoma and three (20%) a corticotroph cell hyperplasia. We found four recurrences after the transsphenoidal surgery (26%), with a mean time for recurrence of 105 months. We found that recurrence was more frequent in subjects with hyperplasia, and in those subjects with lower right/left ACTH ratio. CONCLUSION: Our study, which was focused on patients with CD with no pituitary adenoma detected by MRI and a positive CRH test after CIPS, has found that 20% showed corticotroph cell hyperplasia as the cause of CD. Right/left ACTH ratio after CIPS was useful to differentiate adenoma from hyperplasia. This finding may have important prognostic and treatment implications. More studies are necessary to confirm our result.

Renal Histologic Findings in Necropsies of Type 2 Diabetes Mellitus Patients.

Background: Very few studies have analyzed early histologic lesions of diabetic nephropathy (DN) in patients without signs of clinical involvement (microalbuminuria). In this study, we analyzed renal histologic lesions in necropsies of diabetic patients with or without previous signs of DN. Methods: Histological material was analyzed from 21 autopsies of type 2 diabetes mellitus (T2DM) patients (9 with albuminuria and 12 without albuminuria) and 4 controls. Histologic lesions were evaluated according to the Tervaert classification. Results: Kidneys of diabetic patients presented significantly higher scores in most histologic indices analyzed (glomerular basal membrane thickening, mild and severe mesangial expansion, nodular sclerosis, interstitial fibrosis, and tubular atrophy) than in nondiabetic controls (p < 0.01 in all cases). In contrast, no significant differences were detected between histologic scores when comparing the 21 diabetic patients with and without albuminuria. A significant percentage of cases without albuminuria showed moderate to severe histologic lesions, particularly severe mesangial expansion and severe glomerular vascular lesions. No significant differences were found in age, blood pressure, diabetes vintage, BMI, HbA1c, cholesterol, triglycerides, or treatments between the two (albuminuric vs. nonalbuminuric) T2DM patient groups. Conclusions: Our data suggest that histologic lesions of DN are present in the early stages of the disease, even without albuminuria presence. More precise and earlier metabolic control is recommended in T2DM, and monitoring of risk factors can play a role in DN development.

[Undergraduate Pathology: Video tutorials including digital pathology make teaching more practical and the subject more attractive]. / Anatomía Patológica para el estudiante de Medicina: videotutoriales con integración de Patología digital como una valiosa herramienta para hacer la asignatura más práctica y atractiva.

INTRODUCTION AND OBJECTIVES: Although pathology is one of the cornerstone subjects of the medical curriculum, for many students it can prove too theoretical and remote from clinical relevance. We present the results of a new distance learning project designed to make the teaching of pathology more practical and render the subject more attractive to the medical student. MATERIALS AND METHODS: We developed a teaching programme which included digital pathology images and video tutorials of clinical cases; the students were required to arrive at a final diagnosis. An explanatory video of how biopsies are processed was also included. Twitter was used for rapid interaction with the students. A questionnaire was then completed by the participants evaluating the various aspects of the project. RESULTS: All the students reached a correct diagnosis for the clinical cases. 89% of the participants were extremely satisfied with the project. The majority agreed that the different activities were interesting and useful for improving their understanding of pathology and thus recommended that they should be continued. CONCLUSIONS: Our results support the inclusion of digital pathology into the curriculum together with video tutorials to enhance undergraduate pathology teaching. In the future, such distance learning could prove a useful resource in combination with conventional face-to-face lectures and tutorials.

Anatomía Patológica para el estudiante de Medicina: videotutoriales con integración de Patología digital como una valiosa herramienta para hacer la asignatura más práctica y atractiva / Undergraduate Pathology: Video tutorials including digital pathology make teaching more practical and the subject more attractive

Introducción y objetivo: La asignatura de Anatomía Patológica es fundamental en la formación del estudiante de Medicina. Sin embargo, para muchos estudiantes la asignatura presenta un excesivo contenido teórico, poco trasladable a la práctica clínica. Presentamos los resultados de un proyecto de innovación docente dirigido a facilitar la transmisión del conocimiento a distancia y hacer de la Anatomía Patológica una asignatura más práctica y atractiva para el estudiante de Medicina. Materiales y métodos: Elaboramos material didáctico integrando imágenes de enfermedad digital con videotutoriales para la exposición de casos clínicos donde los alumnos debían llegar al diagnóstico final. Creamos un vídeo explicativo donde exponemos como se procesan las biopsias y utilizamos redes sociales (Twitter) para mantener una comunicación más fluida con los estudiantes. Finalmente, valoramos la percepción del estudiante sobre las actividades realizadas a través de una encuesta. Resultados: Al final de la actividad todos los alumnos resolvieron los casos clínicos y llegaron al diagnóstico correcto de manera exitosa. El 89% de los alumnos mostró un alto nivel de satisfacción con la actividad. Para la mayoría de los participantes la actividad resultó interesante y didáctica, mejorando su experiencia de aprendizaje, por lo que recomendaban mantenerla en el futuro. Conclusiones: Nuestros resultados soportan la integración de la enfermedad digital en combinación con video tutoriales como una herramienta exitosa en el aprendizaje de la Anatomía Patológica. Este modelo podría mantenerse en el futuro como un recurso útil en combinación con el aprendizaje presencial.(AU)

Introduction and objectives: Although pathology is one of the cornerstone subjects of the medical curriculum, for many students it can prove too theoretical and remote from clinical relevance. We present the results of a new distance learning project designed to make the teaching of pathology more practical and render the subject more attractive to the medical student. Materials and methods: We developed a teaching programme which included digital pathology images and video tutorials of clinical cases; the students were required to arrive at a final diagnosis. An explanatory video of how biopsies are processed was also included. Twitter was used for rapid interaction with the students. A questionnaire was then completed by the participants evaluating the various aspects of the project. Results: All the students reached a correct diagnosis for the clinical cases. 89% of the participants were extremely satisfied with the project. The majority agreed that the different activities were interesting and useful for improving their understanding of pathology and thus recommended that they should be continued.Conclusions: Our results support the inclusion of digital pathology into the curriculum together with video tutorials to enhance undergraduate pathology teaching. In the future, such distance learning could prove a useful resource in combination with conventional face-to-face lectures and tutorials.(AU)

IgA-Dominant Infection-Associated Glomerulonephritis Following SARS-CoV-2 Infection.

The renal involvement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported. The etiology of kidney injury appears to be tubular, mainly due to the expression of angiotensin-converting enzyme 2, the key joint receptor for SARS-CoV-2; however, cases with glomerular implication have also been documented. The multifactorial origin of this renal involvement could include virus-mediated injury, cytokine storm, angiotensin II pathway activation, complement dysregulation, hyper-coagulation, and microangiopathy. We present the renal histological findings from a patient who developed acute kidney injury and de novo nephrotic syndrome, highly suggestive of acute IgA-dominant infection-associated glomerulonephritis (IgA-DIAGN) after SARS-CoV-2 infection, as evidenced by the presence of this virus detected in the renal tissue of the patient via immunohistochemistry assay. In summary, we document the first case of IgA-DIAGN associated to SARS-CoV-2. Thus, SARS-CoV-2 S may act as a super antigen driving the development of multisystem inflammatory syndrome as well as cytokine storm in patients affected by COVID-19, reaching the glomerulus and leading to the development of this novel IgA-DIAGN.

Primary cutaneous biphasic sarcomatoid basal cell carcinoma with myoepithelial carcinoma differentiation: A new variant.

Isolated cases of basal cell carcinoma (BCC) with partial myoepithelial component have been described. However, myoepithelial differentiation has not been described in sarcomatoid basal cell carcinomas, which usually show features resembling osteosarcoma, chondrosarcoma, or leiomyosarcoma. We report a case of an 87-year-old man with a forehead lesion that histologically showed a minor component of conventional nodular BCC in transition with a major biphasic sarcomatoid growth composed of invasive spindle-cell and epithelial-like components, the latter with a reticular pattern and scattered ductal structures. Both components showed cytological atypia and high mitotic rate (26/10HPF), with atypical mitotic figures. BER-EP4 immunostaining was exclusively found in the nodular BCC component whereas the sarcomatoid component revealed immunostaining for α-smooth muscle actin (SMA), muscle-specific actin (MSA), calponin, and p63 in both epithelial-like and spindle-cell populations. Focal immunoreactivity was observed in the epithelial component for S100 and glial fibrillary acidic protein (GFAP). Furthermore, EWSR1-PBX1 gene fusion was also detected. This is to our knowledge, the first fully documented case of biphasic sarcomatoid BCC with myoepithelial carcinoma differentiation.

Downregulation of intratumoral expression of miR-205, miR-200c and miR-125b in primary human cutaneous melanomas predicts shorter survival.

While only 15-25 percent of melanoma patients develop distant metastasis and die, this disease is still responsible for the majority of skin cancer-related deaths. The availability of adjuvant therapies makes the selection of high-risk patients essential. We evaluated the intratumoral expression of ten miRNAs in primary melanomas in relation to its ability to predict melanoma survival. To this end, we correlated miRNA expression in 132 cryopreserved primary and metastatic tumors with clinicopathological factors and clinical outcome. We found sequential downregulation of intratumoral expression of miR-125b, miR-182, miR-200c and miR-205 over the full spectrum of melanoma progression. Moreover, downregulation of these miRNAs occurred in primary melanomas that further disseminated to distant sites. Furthermore, miR-125b, miR-200c and miR-205 correlated as independent factors with shorter survival. Our in vitro findings demonstrate that loss of miR-205 potentiates the invasive ability of melanoma cells. We conclude that the downregulation of miR-205 in primary melanomas is an intrinsic property that might contribute to distant metastasis. In particular, the interaction of melanoma cells with the extracellular matrix is one of the key mechanisms by which miR-205 influences melanoma metastasis. In conclusion, miR-125b, miR-200c and miR-205 are useful prognostic biomarkers at the time of diagnosis to select high-risk patients.

Bascule syndrome associated with syncopal episodes.

Bascule syndrome is a recently described benign vasomotor dermatosis characterized by Bier anemic spots, cyanosis, and urticaria-like eruption. We report a case of a 13-year-old girl with cutaneous lesions consistent with Bascule syndrome who had had three exercise-related syncopal episodes. It would be recommended to exclude orthostatic intolerance or postural orthostatic tachycardia syndrome when evaluating patients with Bascule syndrome.

Progastrin represses the alternative activation of human macrophages and modulates their influence on colon cancer epithelial cells.

Macrophage infiltration is a negative prognostic factor for most cancers but gastrointestinal tumors seem to be an exception. The effect of macrophages on cancer progression depends on their phenotype, which may vary between M1 (pro-inflammatory, defensive) to M2 (tolerogenic, pro-tumoral). Gastrointestinal cancers often become an ectopic source of gastrins and macrophages present receptors for these peptides. The aim of the present study is to analyze whether gastrins can affect the pattern of macrophage infiltration in colorectal tumors. We have evaluated the relationship between gastrin expression and the pattern of macrophage infiltration in samples from colorectal cancer and the influence of these peptides on the phenotype of macrophages differentiated from human peripheral monocytes in vitro. The total number of macrophages (CD68+ cells) was similar in tumoral and normal surrounding tissue, but the number of M2 macrophages (CD206+ cells) was significantly higher in the tumor. However, the number of these tumor-associated M2 macrophages correlated negatively with the immunoreactivity for gastrin peptides in tumor epithelial cells. Macrophages differentiated from human peripheral monocytes in the presence of progastrin showed lower levels of M2-markers (CD206, IL10) with normal amounts of M1-markers (CD86, IL12). Progastrin induced similar effects in mature macrophages treated with IL4 to obtain a M2-phenotype or with LPS plus IFNγ to generate M1-macrophages. Macrophages differentiated in the presence of progastrin presented a reduced expression of Wnt ligands and decreased the number and increased cell death of co-cultured colorectal cancer epithelial cells. Our results suggest that progastrin inhibits the acquisition of a M2-phenotype in human macrophages. This effect exerted on tumor associated macrophages may modulate cancer progression and should be taken into account when analyzing the therapeutic value of gastrin immunoneutralization.

Intracellular coexpression of CXC- and CC- chemokine receptors and their ligands in human melanoma cell lines and dynamic variations after xenotransplantation.

BACKGROUND: Chemokines have been implicated in tumor progression and metastasis. In melanoma, chemokine receptors have been implicated in organ selective metastasis by regulating processes such as chemoattraction, adhesion and survival. METHODS: In this study we have analyzed, using flow cytometry, the systems formed by the chemokine receptors CXCR3, CXCR4, CXCR7, CCR7 and CCR10 and their ligands in thirteen human melanoma cell lines (five established from primary tumors and eight established from metastasis from different tissues). WM-115 and WM-266.4 melanoma cell lines (obtained from a primary and a metastatic melanoma respectively) were xenografted in nude mice and the tumors and cell lines derived from them were also analyzed. RESULTS: Our results show that the melanoma cell lines do not express or express in a low degree the chemokine receptors on their cell surface. However, melanoma cell lines show intracellular expression of all the aforementioned receptors and most of their respective ligands. When analyzing the xenografts and the cell lines obtained from them we found variations in the intracellular expression of chemokines and chemokine receptors that differed between the primary and metastatic cell lines. However, as well as in the original cell lines, minute or no expression of the chemokine receptors was observed at the cell surface. CONCLUSIONS: Coexpression of chemokine receptors and their ligands was found in human melanoma cell lines. However, this expression is intracellular and receptors are not found at the cell membrane nor chemokines are secreted to the cell medium. The levels of expressed chemokine receptors and their ligands show dynamic variations after xenotransplantation that differ depending on the origin of the cell line (from primary tumor or from metastasis).

The density and type of MECA-79-positive high endothelial venules correlate with lymphocytic infiltration and tumour regression in primary cutaneous melanoma.

AIMS: Tumour-infiltrating lymphocytes have prognostic value in malignant melanoma. High endothelial venules (HEVs) are specialized vessels present in lymph nodes and tertiary lymphoid organs. CCL19, CCL21 and CCR7 regulate lymphocyte migration through HEVs. The aim of our study was to correlate HEV density in cutaneous primary and metastatic malignant melanomas with clinicopathological parameters, and with CCL19, CCL21 and CCR7 mRNA expression. METHODS AND RESULTS: High endothelial venule density was evaluated by immunohistochemistry with a specific antibody, MECA-79, and chemokine expression was evaluated by real-time PCR. MECA-79-positive vessels, covered by cuboidal (C-HEV) or flat (F-HEV) endothelium, were detected in 55% of melanomas. HEV density was higher in primary melanomas than in metastases. Positive correlations were found between C-HEV density and lymphocytic infiltration, and between F-HEV density and tumour regression. Cases in which the number of C-HEVs exceeded that of F-HEVs had higher levels of CCL19, CCL21, and CCR7. CONCLUSIONS: Our results support a predominant role for C-HEV in the recruitment of lymphocytes in cutaneous melanomas, mediated by CCL19 and CCL21, whereas the density of F-HEV strongly correlates with tumour regression, Therefore, cuboidal and flat HEVs may serve as indicators of the active and late quiescent phases, respectively, of tumour regression in cutaneous malignant melanoma.

Multiple lentigines confined to a resolving psoriatic plaque.

Development of nevus spilus-like lentigines in zones previously affected by plaques of psoriasis has been described. Most cases have appeared following phototherapy; then it has been suggested that the mechanism involved could be an abnormal reaction to UV light. However, cases of multiple lentigines arising within resolving psoriatic in patients who had not received phototherapy or photochemotherapy have been described as a result of possible post-inflammatory hyperpigmentation. We report the case of patient who developed nevus spilus-like lentigines following therapy with topical calcipotriol on psoriatic plaques. We consider that the mechanism of production of lentigines is an unusual form of postinflammatory hyperpigmentation.