Surgical management of thymic epithelial tumors in children: lessons from the French Society of Pediatric Oncology and review of the literature.

PURPOSE: We report the results of a French multicenter retrospective study based on a period of more than 30 years and a review of the literature in order to more clearly define the surgical approach and specific pediatric risk factors. METHODS: Clinical data of children comprising all histologic subtypes of thymic epithelial tumors (TET) treated between 1979 and 2009 in French pediatric oncology centers were retrospectively analyzed and discussed in the light of a review of all pediatric cases reported in the literature. RESULTS: Nine cases were identified, corresponding to five females and four males with a median age of 13 years (range: 7.5-17). Histologic subtypes were type AB (n = 1), type B (n = 5) and type C (n = 3). Treatment consisted of tumor resection (4 R0, 4 R1, 1 R2) via right anterior thoracotomy, posterolateral thoracotomy, left thoracoscopy, sternotomy and cervicosternotomy, and/or chemotherapy, mainly cyclophosphamide-doxorubicin-cisplatin (CAP; n = 5), and/or radiotherapy (n = 4). Two patients with TET type C died. All other patients are alive with a median follow-up of 4 years (range: 1.5-20). Review of a total of 93 pediatric cases reported in the literature showed statistically significant associations between less favorable histologic subtypes and male gender (P = 0.012), advanced Masaoka stage (P < 0.001) and quality of resection (P < 0.001) respectively. CONCLUSIONS: A review of the literature and our series identified several risk factors to take into account in the therapeutically decision. Complete resection through a sternotomy is highly recommended.

Clinical and molecular practice of European thoracic pathology laboratories during the COVID-19 pandemic. The past and the near future.

BACKGROUND: This study evaluated the consequences in Europe of the COVID-19 outbreak on pathology laboratories orientated toward the diagnosis of thoracic diseases. MATERIALS AND METHODS: A survey was sent to 71 pathology laboratories from 21 European countries. The questionnaire requested information concerning the organization of biosafety, the clinical and molecular pathology, the biobanking, the workload, the associated research into COVID-19, and the organization of education and training during the COVID-19 crisis, from 15 March to 31 May 2020, compared with the same period in 2019. RESULTS: Questionnaires were returned from 53/71 (75%) laboratories from 18 European countries. The biosafety procedures were heterogeneous. The workload in clinical and molecular pathology decreased dramatically by 31% (range, 3%-55%) and 26% (range, 7%-62%), respectively. According to the professional category, between 28% and 41% of the staff members were not present in the laboratories but did teleworking. A total of 70% of the laboratories developed virtual meetings for the training of residents and junior pathologists. During the period of study, none of the staff members with confirmed COVID-19 became infected as a result of handling samples. CONCLUSIONS: The COVID-19 pandemic has had a strong impact on most of the European pathology laboratories included in this study. Urgent implementation of several changes to the organization of most of these laboratories, notably to better harmonize biosafety procedures, was noted at the onset of the pandemic and maintained in the event of a new wave of infection occurring in Europe.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids.

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

CD52, CD22, CD26, EG5 and IGF-1R expression in thymic malignancies.

BACKGROUND: Thymic epithelial tumours are rare cancers for which new treatment options are required. Identification of putative predictive markers is important for developing clinical trials. We studied the expression of five putative predictive biomarkers, potentially actionable by approved experimental drugs. METHODS: CD52, CD22, CD26, EG5, and IGF-1R expression were investigated by immunohistochemistry in formalin-fixed surgical samples of thymic epithelial tumour patients. All samples containing 10% positive epithelial tumour cells, independent of tumour cell intensity, were considered as positive. Correlation with histological subtype was performed. RESULTS: 106 surgical samples (89 thymomas, 12 thymic carcinoma, and 5 thymic neuroendocrine tumours) were evaluated. Overall, CD52, CD22, CD26, EG5 and IGF-1R expression was observed in 7%, 42%, 25%, 42% and 77% of samples, respectively. CD52 expression was more frequent in B2 and B3 thymoma. All TET subtypes stained for CD22, mainly AB thymoma (68%). CD26 expression also correlated with AB thymoma (68%), and A thymoma (50%) subtype, while IGFR1 was the most common marker expressed by thymic carcinoma samples (92%), followed by EG5 (60%). Only EG5 expression was significantly higher in thymic carcinomas than in thymomas (75% vs. 38%, p=0.026). CONCLUSIONS: Our data were consistent with a previous study of IGF-1R expression. Based on their expression, activity of agents targeting CD52, CD 22, CD26 and EG5 could be further explored in TET patients.

[Parathyroid cyst of the anterior mediastinum]. / Kyste parathyroidien du médiastin antérieur.

A mediastinal cyst measuring 6 cm was removed by manubriotomy in a 66-year-old woman. This patient had no clinical or biological evidence of hyperparathyroidism. The cyst was close to the thymus and compressed the innominate venous trunk. It contained a clear fluid. Normal parathyroid tissue was present in the capsular wall that was fibrous and partially calcified. This cysts are rare and their mediastinal localization is exceptional.

[Adiaspiromycosis, 2 cases of incidental finding]. / Adiaspiromycose, 2 cas de diagnostic fortuit.

Two apparently solitary granulomas, each containing an adiaconidia, 200 and 300 microm in diameter, were incidentally found in the lung parenchyma on a pleuro-pneumonectomy specimen for malignant mesothelioma, and in the stroma of a pulmonary adenocarcinoma, respectively. These two cases of adiaspiromycosis illustrate well the characteristic morphology of this strictly pulmonary, rare, ubiquitous, and histologically diagnosed mycosis.

Granular cell tumours of the lower respiratory tract.

Granular cell tumours rarely involve the lower respiratory tract. We report eight cases surgically resected at our institution. There were four females and four males, aged between 18 to 56 years (mean 40). One tumour associated with a peripheral lung adenocarcinoma was asymptomatic. The other lesions presented with obstructive pneumonitis (3 cases), haemoptysis (2), dyspnea (1) or cough (1). These tumours were tracheal (1) or bronchial (6) and one case was located in the lung parenchyma. Four cases were multicentric with associated lesions located in a bronchus (2), the oesophagus (1) or a mediastinal lymph node (1). All tumours, with the largest diameter ranging from 0.5-4.5 cm, were histologically invasive. The tumours were positive for S-100 protein, neuron specific enolase, KP1 (CD68) and vimentin. No tumour expressed desmin, keratin or p53 oncoprotein. Our study demonstrates that, in spite of marked anatomical and clinical polymorphism, the rare granular cell tumours of the lower respiratory tract have a constant histological appearance. Our observations confirm that large tumours (> 8-10 mm) usually extend beyond the tracheo-bronchial cartilages and, therefore, only surgical treatment may avoid recurrence.

Giant bilateral fibrous dysplasia of first ribs: compression of mediastinum and thoracic outlet.

A 43 year old woman presented with two large bilateral tumours of the first ribs that compressed the right subclavian vessels, trachea and oesophagus and led to right arm oedema, severe dyspnoea and dysphagia. The resected tumours showed typical histological features of fibrous dysplasia without malignant transformation. The right tumour weighed 1.5 kg and measured 17 x 13 x 10 cm. This report demonstrates that major surgery is still possible for resection of such exceptional giant compressive lesions, since fibrous dysplasia is a benign and non-infiltrative tumour.

Glycoconjugate secretion in human airways in vitro: effects of epithelium removal.

The aim of this study was to examine glycoconjugate secretion in human airways with and without an epithelium. Glycoconjugate release in supernatants derived from human airways in vitro was determined using an ELISA assay with an anti-human mucin monoclonal antibody (MAb 3D3). This monoclonal antibody reacted strongly with Le(b) antigen but also recognized in vitro Le(a) and Le(y) determinants. In 11 of the 34 different lung samples (32%) studied the glycoconjugate levels were below the threshhold of detection for this assay. The mean basal secretion of glycoconjugates in human airways in vitro was 100+/-28 microg/g tissue (Period I; n = 23 different lung samples). The amount of glycoconjugate measured in the medium derived from human isolated bronchial ring preparations did not change under control conditions during the course of the experimental procedure (Period I; 128+/-46 microg/g tissue and Period II; 159 +/-48 microg/g tissue; n = 13 paired lung samples). In the supernatants of airway preparations with an intact epithelium the amount of glycoconjugates detected was 90+/-38 microg/g tissue (Period I; n = 12 different lung samples) and removal of the epithelium did not alter this basal glycoconjugate release (94+/-60 microg/g tissue: Period I, n = 8 different lung samples). The absence of the epithelial layer was confirmed by histological evaluation. Methacholine (100 microM) induced a 10- and four-fold increase in glycoconjugate release from airways with and without an epithelium, respectively. In contrast, in preparations with an epithelium, LTD4 (10 microM) and anti-IgE (dilution: 1/1000) did not cause an increase of glycoconjugate release. The methacholine difference between airways with and without an epithelium was not significantly different (P > 0.10). However, a treatment with atropine (100 microM) prevented the increase of glycoconjugate release in preparations with an epithelium. These data derived from a limited number of experiments suggest that the epithelium may not regulate the basal or stimulated release of glycoconjugates from isolated human airways.

M1/MUC5AC mucin released by human airways in vitro.

A series of monoclonal antibodies which bind to a mucin known as M1 (anti-M1 MAbs) have also been shown to detect the product of the human gene MUC5AC. The aim of this investigation was to determine the concentration of the M1 mucin in the surface epithelium of human bronchial preparations by means of immunohistochemistry and in the bronchial fluid derived from human airways by means of an immunoradiometric assay. Human bronchial ring preparations from the resection material of 20 patients were challenged with methacholine, leukotriene D4, or anti-immunoglobulin E. Experiments were performed in preparations with an intact epithelium as well as in tissues in which the epithelium had been mechanically removed. The anti-M1 MAbs stained the goblet cells in the epithelium intensely and there was also light and less uniform staining in the submucosa. The M1/MUC5AC mucin in the fluids secreted by the bronchial preparations was not modified during either the experimental protocol or stimulation with the different secretagogues. However, in preparations in which the epithelium had been removed, there was a significant reduction in the amount of M1/MUC5AC mucin detected. These data suggest that the M1/MUC5AC mucin detected in the biological fluids produced by human airways in vitro may be released constantly, and principally from the goblet cells in the epithelial layer.