[PD-L1 : a natural immunosuppressor related to carcinogenesis. A pathologist's point of view]. / Le PD-L1 : un immunosuppresseur naturel impliqué dans la carcinogenèse Le point de vue du pathologiste.

The goal of this article is to emphasize the role of anatomopathology for the intratumoral detection of the immune checkpoint PD-L1. This molecule is one of the main targets in the anti-cancer immunotherapy. The binding of PD-L1 to its receptor PD-1 results in the inactivation of the cytotoxic T-cells, thus providing a mechanism of keeping immune reactions under control. This process can be circumvented by tumour cells to evade immune system. By blocking PD-1/PD-L1 binding, it is possible to reactivate T-cells targeting tumour neo-antigens. This article focuses on how PD-L1 works, on its implication in neoplastic processes, on the general principles of its therapeutic blockade, on the biomarkers underlying the treatment efficacy and on the practical implications of these biomarkers, especially in the anatomopathological practice.

Le but de cet article est de démontrer le rôle de l'anatomie pathologique dans la détection intra-tumorale du checkpoint immunitaire PD-L1. Ce dernier est l'une des principales cibles de l'immunothérapie à visée oncologique. La liaison du ligand PD-L1 à son récepteur PD-1 permet d'inhiber l'action des lymphocytes T cytotoxiques et, ainsi, de garder sous contrôle les réactions immunitaires. Ce processus peut être détourné par les cellules tumorales pour échapper à l'immunosurveillance. En bloquant le couple PD-L1/PD-1, il est possible de réactiver les lymphocytes T dirigés contre les néo-antigènes tumoraux. Nous nous concentrons, dans cet article, sur le mode de fonctionnement général de PD-L1, sur son implication dans les processus néoplasiques, sur le principe de son blocage thérapeutique, sur les biomarqueurs de l'efficacité du traitement et sur l'utilisation pratique de ces biomarqueurs, particulièrement dans la pratique anatomo-pathologique.

[Lung lesions in severe COVID-19 : anatomoclinical confrontation]. / Lésions pulmonaires dans la COVID-19 sévère : confrontation anatomoclinique.

We report the fatal outcome of two patients infected by SARS-CoV-2 and exhibiting severe lung lesions at the thoracic imaging and autopsic examination. We also describe the biosecurity measures to adopt when performing autopsies during the Covid-19 pandemia.

Nous rapportons l'évolution fatale de deux patients infectés par le SARS-CoV-2 et porteurs de lésions pulmonaires sévères à l'imagerie thoracique et à l'examen autopsique. Nous décrivons également les mesures de biosécurité à adopter pour la réalisation des autopsies au cours de la pandémie de la Covid-19.

First report of probe based confocal laser endomicroscopy during medical thoracoscopy.

Probe based confocal laser endomicroscopy (pCLE) is a new optical endoscopic technique, generating fluorescent light emission from the tissue of interest and allowing in vivo live imaging at a cellular level ("optical biopsies"). To the best of our knowledge, this article is the first to present pCLE images during medical thoracoscopy. We present here 3 different patients referred for various health problems. A precise description of pleural cavity pCLE images after intravenous fluorescein injection (a fluorophore) together with corresponding macroscopical and histological studies is performed. This led to the diagnosis of normal pleura in one case, carcinomatous pleuritis in another case and a malignant mesothelioma in the third case. We believe that optical biopsies could help clinicians to make an early diagnosis, thereby allowing rapid therapeutic intervention (talc pleurodesis for example). Furthermore, it could help to guide biopsies when affected zones are not obvious to macroscopic examination. In a near future, new fluorophores could be developed to stain some pathophysiological processes, therapeutic targets, or enzymes activities bringing new insights in endoscopic pleural disease work-up.

[Breast cancer: the interest of pathological classification]. / Cancer du sein: importance de la nomenclature anatomo-pathologique.

The breast pathology includes a large array of entities for which macroscopic and microscopic analysis remains fundamental. Tissue and cell morphology allows in most cases the distinction between benign or malignant tumours and therefore provides the clinicians with essential information for the therapeutic strategy. In the Pathology laboratory, immunohistochemistry and molecular biology have improved the specificity of the diagnosis and have introduced new prognostic and predictive markers for tumour management. The last edition of the WHO classification, released in 2003, distinguishes 21 varieties of invasive carcinoma and 2 categories of intraepithelial neoplasia based on the morphology and immunohistochemical profile. Other diseases can affect the breast, although much less frequently, such as Paget's disease of the nipple, phyllode tumours, sarcomas, lymphomas... These diseases will not be reviewed here.

[Neuroendocrine tumors of the appendix]. / Tumeurs neuroendocrines appendiculaires: à propos d'un cas, de l'histologie à la thérapeutique.

An 19-year-old woman was admitted for acute appendicitis. The histological study of the appendix revealed a tubular variant of endocrine carcinoma of the appendix. Neuroendocrine tumors ("NETs") of the appendix are rare tumors which are usually detected incidentally, affecting 0.3% to 0.9% of appendectomies. Depending on their size, but also on some other factors, including histologic type, these tumors will require specific treatment; sometimes appendectomy will not be sufficient.

Torsion of the gallbladder: two case reports.

Torsion of the gallbladder is a rare disease. It is simply defined as a rotation of the gallbladder on its mesentery along the axis of the cystic duct and cystic artery. The aetiology is unknown. However, several factors are postulated as playing causative roles. The disease symptoms mimic acute cholecystisis. The current value of radiological imaging is limited, but clinically, volvulus of the gallbladder is an acute surgical situation. It may be treated and diagnosed by a laparoscopic approach.

Adrenal ganglioneuroma. A neoplasia to exclude in patients with adrenal incidentaloma.

OBJECTIVE: To determinate the MRI and CT scanning appearance of adrenal ganglioneuroma and correlate the imaging with histological features. SUMMARY BACKGROUND DATA: In the last 10 years, eight patients with a pathologically proven adrenal ganglioneuroma were operated on in our department of endocrine surgery. To our knowledge, these patients represent one the largest reported cohorts of adrenal ganglioneuroma treated in a single institution. METHODS: All these eight patients had a comprehensive hormonal work up and underwent CT and/or MRI. Biological data, radiological features and histological findings were thoroughly reviewed in order to further characterize these tumours. RESULTS: The most relevant characteristics of adrenal GN resected in our patients were: No hormonal hypersecretion, Presence of calcifications; no vessel involvement; and a non-enhanced attenuation of less than 40 HU on CT, A low non-enhanced T1W signal, a slightly high and heterogeneous T2W signal, a late and gradual enhancement on dynamic MRI, especially if associated with a whorled pattern. CONCLUSIONS: Even if many aggressive tumours, mainly adrenal carcinoma, may share some of these radiological features, the presence of all or most of them must made the clinician evoke the diagnosis of GN.

[Clinical case of the month. Constipation and abdominal mass syndrome in a 51-year-old patient]. / Le cas clinique du mois. Constipation et syndrome de masse abdominale chez une patiente de 51 ans.

A 51-year old patient consults for abdominal swelling and persistent constipation. Clinical exploration shows the presence of a left iliac fossa tumor corresponding to a papillary serous adenocarcinoma of the fallopian tube after macroscopic and microscopic examination. The diagnostic and therapeutic problems caused by this rare gynecologic tumor are discussed.