EBUS-guided transbronchial mediastinal cryobiopsy in the diagnosis of mediastinal lesions: safety, feasibility and diagnostic yield – experience in 50 cases

Background

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) is the technique of choice in the study of mediastinal and hilar lesions; however, it can be affected by the insufficiency of intact biopsy samples, which might decrease its diagnostic yield for certain conditions, thus requiring re-biopsies or additional diagnostic procedures such as mediastinoscopy when probability of malignancy remains high.

Objectives

Our objectives were to 1) attempt to reproduce this technique in the same conditions that we performed EBUS-TBNA, that is, in the bronchoscopy suite and under moderate sedation; 2) describe the method used for its execution; 3) determine its feasibility by accessing different lymph node stations applying our method; 4) analyze the diagnostic yield and its complications.

Methods

Prospective study of 50 patients who underwent EBUS-TBNA and EBUS-guided TMC in a single procedure using a 22-G TBNA needle and a 1.1 mm cryo-probe subsequently between January and August 2022. Patients with mediastinal lesions greater than 1 cm were recruited and EBUS-TBNA and TMC were performed in the same lymph node station.

Results

The diagnostic yield was 82% and 96% for TBNA and transbronchial mediastinal cryobiopsy, respectively. Diagnostic yields were similar for sarcoidosis, while cryobiopsy was more sensitive than TBNA in lymphomas and metastatic lymph nodes. As for complications, there was no pneumothorax and in no case was there significant bleeding. There were no complications during the procedure or in the follow-up of these patients.

Conclusions

TMC following our method is a minimally invasive, rapid, and safe technique that can be performed in a bronchoscopy suite under moderate sedation, with a higher diagnostic yield than EBUS-TBNA, especially in cases of lymphoproliferative disorders and mestastatic lymph nodes, or when more biopsy sample is needed for molecular determinations.

Comparison of biotransformation of inorganic selenium by Lactobacillus and Saccharomyces in lactic fermentation process of yogurt and kefir

The aim of the present study was to characterize, quantify, and compare the different selenium species that are produced when lactic fermentation with two different types of microorganisms, bacteria (Lactobacillus) and yeast (Saccharomyces), take place to produce yogurt and kefir, respectively, and to study the transformation process of these species as a function of time. These two dairy products were chosen for the study because they are highly consumed in different cultures. Moreover, the microorganisms present in the fermentation processes are different. While the bacteria Lactobacillus is the one responsible for yogurt fermentation, a partnership between bacteria and the yeast Saccharomyces causes kefir fermentation. A comparative study has been carried out by fermenting Se(IV) enriched milk in the presence of both types of microorganisms, where the concentration range studied was from 0.5 to 20 microg g (-1). Enzymatic extraction enabled selenium speciation profiles, obtained by anionic exchange and ion-pairing reversed phase high performance liquid chromatography (IP-RP-HPLC) with inductively coupled plasma mass spectrometry (ICP-MS) detection. Scanning electron microscopy (SEM) applied to the enriched samples showed segregated Se (0), at added concentrations higher than 5 microg g (-1). The main Se species formed depended on the type of microorganism involved in the fermentation process, SeCys 2 and MeSeCys being the main species generated in yogurt and SeMet in kefir. The results obtained are different for both kinds of samples. Lactic fermentation for yogurt produced an increment in selenocystine (SeCys 2) and Se-methylselenocysteine (MeSeCys), while fermentation to produce kefir also incremented the selenomethionine (SeMet) concentration. The Se species are stable for at least 10 and 15 days for kefir and yogurt, respectively. After this period, selenocystine concentration decreased, and the concentration of Se-methylselenocysteine was found to significantly increase.

[Microhematuria secondary to mucocele and appendicular cystoadenoma]

Appendiceal mucocele is a rare entity consisting of cystic dilatation of the appendix as a result of increased mucus production. Most cases are related to the presence of a cystadenoma. This appendiceal neoplasm is frequently associated with other extraintestinal and colonic tumors and therefore adequate abdominal examination is necessary. The clinical presentation is nonspecific and varies from asymptomatic forms to abdominal discomfort and, less frequently, to urological manifestations. We describe the case of a woman with hematuria associated with an appendiceal mucocele. Only a few cases have been reported in the medical literature. The treatment of choice of cystadenoma is surgery and simple mucocele cannot be macroscopically differentiated from cystadenoma and cystadenocarcinoma. Survival in patients with appendiceal cystadenoma is excellent. The 5-year survival rate is reduced by at least half in patients with cystadenocarcinoma associated with pseudomyxoma peritonei.