Pleural empyema secondary to perforated diverticulosis due to biliary neoplasia infiltration

A long-term female smoker presented to the emergency department with cough, greenish mucus and dyspnoea, without fever. The patient also reported abdominal pain and significant weight loss in recent months. Laboratory tests showed leucocytosis with neutrophilia, lactic acidosis and a faint left lower lobe consolidation on chest X-ray, for which she was admitted to the pneumology department and started on broad-spectrum antibiotherapy. After 3 days of clinical stability, the patient deteriorated rapidly, with worsening of analytical parameters and coma. The patient died a few hours later. Given the rapid and unexplained evolution of the disease, a clinical autopsy was requested, which revealed a left pleural empyema caused by perforated diverticula by neoplastic infiltration of biliary origin.

PD-L1 immunoexpression and molecular characterization of histological subtypes in urothelial carcinoma

INTRODUCTION

Urothelial carcinoma (UC) has histological subtypes whose phenotype reflects their molecular diversity, behavior and response to conventional therapy. Immune checkpoint inhibitors (ICIs) have improved the management of UC by evaluation of PD-L1. In the case of PD-L1 22C3, the initiation of ICI is considered from a combined positive score (CPS) greater than 10. However, UC subtypes with absent PD-L1 22C3 expression in cases with CPS>10 may not respond to these treatments. This study aims to establish a correlation between the PD-L1 immunoexpression and molecular alterations in divergent differentiation and histological subtypes of UC (UC-s).

MATERIAL AND METHODS

Twenty-six samples of UC were detected from a total of 24 patients. Two pathologists performed separately an assessment of UC-s on hematoxylin-eosin as well as PD-L1 expression. Molecular study of each case was performed by next generation sequencing (NGS). A descriptive analysis of the variables included was conducted.

RESULTS

Nine cases (34.61%) showed a CPS>10, some with negative PD-L1 immunoexpression in aggressive UC-s. The molecular study revealed alterations in genes belonging to the p53/cell cycle control, RAS, and DNA repair pathways, among others. None of the alterations were exclusive to any histological subtype.

DISCUSSION

Special attention should be paid to CPS>10 cases that include histological subtypes of UC with divergent expression for PD-L1 as they may not respond to treatment with ICI. We recommend examining the proportion and PD-L1 status of each subtype, especially if it has aggressive behavior.

The renin-angiotensin-aldosterone system in rats of both sexes subjected to chronic hypobaric hypoxia

Plasma renin activity (PRA), plasmatic aldosterone, haematocrit, haemoglobin concentration and plasma proteins were measured in 36 Wistar rats of both sexes submitted to 380 mmHg in hypopressure chamber during 7 months and in a group of control animals (15 male and 15 female rats). PRA was significantly increased in hypoxic male (P less than 0.05) and female (P less than 0.01) rats. On the contrary, plasma aldosterone concentration did not show any significant variation. There thus was a clear dissociation between the plasmatic renin-angiotensin system and the aldosterone in rats of both sexes submitted to severe chronic hypobaric hypoxia.