Assessment of the current and emerging criteria for the histopathological classification of lung neuroendocrine tumours in the lungNENomics project.

BACKGROUND: Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort presents a unique opportunity to assess the strengths and limitations of current World Health Organization (WHO) classification criteria and to evaluate the utility of emerging markers. PATIENTS AND METHODS: Patients were diagnosed based on the 2021 WHO criteria, with atypical carcinoids (ACs) defined by the presence of focal necrosis and/or 2-10 mitoses per 2 mm2. We investigated two markers of tumour proliferation: the Ki-67 index and phospho-histone H3 (PHH3) protein expression, quantified by pathologists and automatically via deep learning. Additionally, an unsupervised deep learning algorithm was trained to uncover previously unnoticed morphological features with diagnostic value. RESULTS: The accuracy in distinguishing typical from ACs is hampered by interobserver variability in mitotic counting and the limitations of morphological criteria in identifying aggressive cases. Our study reveals that different Ki-67 cut-offs can categorise LNETs similarly to current WHO criteria. Counting mitoses in PHH3+ areas does not improve diagnosis, while providing a similar prognostic value to the current criteria. With the advantage of being time efficient, automated assessment of these markers leads to similar conclusions. Lastly, state-of-the-art deep learning modelling does not uncover undisclosed morphological features with diagnostic value. CONCLUSIONS: This study suggests that the mitotic criteria can be complemented by manual or automated assessment of Ki-67 or PHH3 protein expression, but these markers do not significantly improve the prognostic value of the current classification, as the AC group remains highly unspecific for aggressive cases. Therefore, we may have exhausted the potential of morphological features in classifying and prognosticating LNETs. Our study suggests that it might be time to shift the research focus towards investigating molecular markers that could contribute to a more clinically relevant morpho-molecular classification.

Chemoradiotherapy efficacy is predicted by intra-tumour CD8+/FoxP3+ double positive T cell density in locally advanced N2 non-small-cell lung carcinoma.

BACKGROUND: Radiotherapy is a standard of care for locally advanced stage III N2 non-small-cell lung carcinoma (NSCLC) combined with surgery/chemotherapy. Radiotherapy is hypothesised to induce tumour immunogenic cell death, to release neoantigen resulting in intra-tumoural immune infiltration and abscopal effect. Conversely, it has not been demonstrated if immune cells are necessary to drive radiotherapy efficacy and predict patient's survival. PATIENTS AND METHODS: We retrospectively analysed tumour samples and clinical data from 113 patients, 89 resected (PORT) and 24 non-resected (DRC) N2-NSCLC treated with chemotherapy and radiotherapy (same radiotherapy department from 2002 to 2015). The immune environment was characterised with in situ multiplex staining (CD8, FoxP3, PD-L1 and cytokeratin) and correlated with clinical data and survival. RESULTS: High density of CD8+ T cells was associated with OS (p = 0.04, HR = 1.93 [0.99-3.78]) and DFS (p = 0.003, HR = 2.42 [1.31-4.47]) in the PORT. High density of CD8+/FoxP3+ double positive cells was associated with OS (p = 0.01, HR = 1.97 [1.11-3.48]) in the whole population, with OS (p = 0.05, HR = 1.92 [0.98-3.74]) and PFS (p = 0.03, HR = 1.83 [1.03-3.23]) in the PORT without reaching significance for the DRC. Intermediate PD-L1 expression in tumour cells (TPS = 1-49%) was associated with a higher survival in the PORT. CONCLUSIONS: Intra-tumoural CD8+ T cell and particularly CD8+/FoxP3+ double positive T cell densities predict survival in stage III N2-NSCLC suggesting the need for a pre-existing intra-tumour immunity to mediate the action of radiotherapy. Density of CD8+/FoxP3+ cells was the best predictor of patient's survival in multivariate analysis and could represent a biomarker of radiotherapy efficacy.

[Malignant pleural mesothelioma: The role of surgery]. / Mésothéliome pleural malin : place de la chirurgie.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare and highly aggressive disease, whose incidence is increasing. Asbestos is the primary causal agent. STATE OF KNOWLEDGE: Knowledge about MPM has evolved. Thoracoscopy is essential for diagnosis of MPM. It allows performing pleural biopsies, to study the extent of the disease and to relieve dyspnea. The pathological diagnosis is also better codified with immunohistochemistry and with analysis by expert of Mesopath group. Curative surgical treatments are pleurectomy decortication and extended pneumonectomy in combination with chemotherapy and/or radiotherapy. Those heavy treatments improve survival in highly selected patients. For the other patients, supportive measures will be considered to reduce pain and dyspnea. PROSPECT: Radical surgical treatment is only offered in therapeutic trials or multimodal treatment. Its place is not formally established. New therapies associated to surgical treatment are being studied. CONCLUSIONS: Surgical management of MPM has to be operated in specialized teams where the survival benefit and quality of life is discussed case by case.

Dedifferentiated primary mediastinal liposarcoma mimicking a thymic tumor.

Mediastinal tumors are heterogeneous and the diagnosis depends on their location in the mediastinum. The most frequent tumors are germinal tumor, lymphoma and thymoma. The clinical and radiological aspects are often not sufficient to orient the diagnosis and biopsy is necessary to confirmed it. Here, we present a rare case of an anterior mediastinal mass incidentally detected in a 63 years old man during assessment for asthma. The lesion was presumptively diagnosed as a thymic epithelial tumor based on location and radiological characteristics. Surgical biopsy revealed a primary dedifferentiated mediastinal liposarcoma with multiple lung metastases.

Late costal osteomyelitis with a cutaneous fistula after flame burns: a case report.

Chest wall defects are an unusual complication of burn injury, generally seen after high-voltage electrical burns. Here we report the case of a 57-year-old man who developed costal chondritis and osteomyelitis 23 months after flame injury, which covered 50% of the total body surface area. Management included the resection of two ribs and coverage with an omental flap, overlaid by a split-thickness skin graft during the same surgical procedure. Declaration of interest: The authors have no conflict of interest to declare.

Solitary fibrous tumor of the pleura: Can computed tomography features help predict malignancy? A series of 56 patients with histopathological correlates.

OBJECTIVE: To identify computed tomography (CT) predictors of malignancy, from a retrospective study of preoperative CT scans of patients with solitary fibrous tumors (SFT) of the pleura. PATIENTS AND METHODS: The CT scans of 56 patients with histopathologically confirmed SFT (33 women and 23 men; mean age, 60years) who underwent surgery between December 2004 and November 2012 were retrospectively analyzed by three radiologists working in consensus, blinded to the final histological diagnosis. RESULTS: SFT was asymptomatic and incidentally discovered in 22 patients (45.8%). Resection specimen analysis (R0 resection in all cases) revealed that 23 tumors (41%) were malignant. The CT features, which significantly differed between malignant and benign SFTs were tumor size (P=0.002) with a discriminative threshold value of 10cm, tumor heterogeneity before (P=0.02) and after (P=0.03) intravenous administration of iodinated contrast material, presence of intratumoral hydric attenuation areas (P=0.01), pleural effusion (P=0.01), measurable intratumoral vessels (P=0.02), hypervascularization with visible intratumoral vessels and/or marked enhancement (P=0.001). Presence of intratumoral calcifications (P=0.2) and maximum post-contrast enhancement value (P=0.6) were not significantly different between the two groups. CONCLUSION: A size greater than or equal to 10cm, hypervascularization, attenuation heterogeneity and association with pleural effusion are individual variables that suggest malignant SFT on CT.

Thoracic endometriosis syndrome: CT and MRI features.

Thoracic endometriosis is considered to be rare, but is the most frequent form of extra-abdominopelvic endometriosis. Thoracic endometriosis syndrome affects women of reproductive age. Diagnosis is mainly based on clinical findings, which can include catamenial pneumothorax and haemothorax, non-catamenial endometriosis-related pneumothorax, catamenial haemoptysis, lung nodules, and isolated catamenial chest pain. Symptoms are typically cyclical and recurrent, with a right-sided predominance. Computed tomography (CT) is the first-line imaging method, but is poorly specific; therefore, its main role is to rule out other pulmonary diseases. However, in women with a typical clinical history, some key CT findings may help to confirm this often under-diagnosed syndrome. MRI can also assist with the diagnosis, by showing signal changes typical of haemorrhage within diaphragmatic or pleural lesions.

High expression of DNA repair pathways is associated with metastasis in melanoma patients.

We have identified a gene-profile signature for human primary malignant melanoma associated with metastasis to distant sites and poor prognosis. We analyse the differential gene expression by looking at whole biological pathways rather than individual genes. Among the most significant pathways associated with progression to metastasis, we found the DNA replication (P=10(-14)) and the DNA repair pathways (P=10(-16)). We concentrated our analysis on DNA repair and found that 48 genes of this category, among a list of 234 genes, are associated with metastatic progression. These genes belong essentially to the pathways allowing recovery of stalled replication forks due to spontaneous blockage or induced DNA lesions. Because almost all these differentially expressed repair genes were overexpressed in primary tumors with bad prognosis, we speculate that primary melanoma cells that will metastasize try to replicate in a fast and error-free mode. In contrast to the progression from melanocytes to primary melanoma, genetic stability appears to be necessary for a melanoma cell to give rise to distant metastasis. This overexpression of repair genes explains nicely the extraordinary resistance of metastatic melanoma to chemo- and radio-therapy. Our results may open a new avenue for the discovery of drugs active on human metastatic melanoma.

[DNA typing: analysis of difficult cases]. / Les empreintes génétiques: des affaires d'interprétation difficile.

DNA fingerprinting is a tool to identify individual and allows to resolve many difficult cases. Their application fields are various: paternity or maternity testing, criminal affairs (crime, identity usurpation, identity substitution...). This review relates some interesting and atypical cases.

[Point about DNA profiling: technologies, applications, and legislation]. / Les empreintes génétiques: état de l'art en 2007, techniques, applications et législation.

Molecular biology progress in DNA fingerprinting has revolutionized forensic science. It's a reliable tool to identify an individual; it provides a true "genetic identity card". It's based of the concept that no two individuals can have an identical DNA pattern except identical twins. This article is a clarification on current technologies used in DNA profiling, their applications and its legislation, according a special place to the national databases (FNAEG), which is in great development for the moment.