(1) It is known that occasional consumption of cocaine causes diffuse alveolar damage, haemorrhage, etc. The cause-effect relationship consumption-appearance in a few hours of spontaneous pneumomediastinum leads us to appreciate this form of consumption as a causal factor rather than a predisposing/precipitating factor as it appears in the literature on the topic. (2) Spontaneous pneumomediastinum is considered a benign disorder but, as shown by our series, a bad outcome may represent an immediate life-threatening condition, forcing an invasive manoeuvre. We always recommend performing a chest CT scan on admission to predict the evolution.

ObjectiveDespite significant progresses in imaging and pathological evaluation, early differentiation between benign and malignant biliary strictures remains challenging. Endoscopic retrograde cholangiopancreatography (ERCP) is used to investigate biliary strictures, enabling the collection of bile. We tested the diagnostic potential of next-generation sequencing (NGS) mutational analysis of bile cell-free DNA (cfDNA).DesignA prospective cohort of patients with suspicious biliary strictures (n=68) was studied. The performance of initial pathological diagnosis was compared with that of the mutational analysis of bile cfDNA collected at the time of first ERCP using an NGS panel open to clinical laboratory implementation, the Oncomine Pan-Cancer Cell-Free assay.ResultsAn initial pathological diagnosis classified these strictures as of benign (n=26), indeterminate (n=9) or malignant (n=33) origin. Sensitivity and specificity of this diagnosis were 60% and 100%, respectively, as on follow-up 14 of the 26 and eight of the nine initially benign or indeterminate strictures resulted malignant. Sensitivity and specificity for malignancy of our NGS assay, herein named Bilemut, were 96.4% and 69.2%, respectively. Importantly, one of the four Bilemut false positives developed pancreatic cancer after extended follow-up. Remarkably, the sensitivity for malignancy of Bilemut was 100% in patients with an initial diagnosis of benign or indeterminate strictures. Analysis of 30 paired bile and tissue samples also demonstrated the superior performance of Bilemut.ConclusionImplementation of Bilemut at the initial diagnostic stage for biliary strictures can significantly improve detection of malignancy, reduce delays in the clinical management of patients and assist in selecting patients for targeted therapies.

Management of stage IV rectal cancer is controversial, and different strategies may be useful. Preoperative chemotherapy for liver metastases might cause pathologic changes over the primary rectal tumor. In this study, the authors show the pathologic regression of the primary rectal tumor after neoadjuvant chemotherapy treatment. Patients suffering stage IV rectal cancer underwent surgery after oxaliplatin-based chemotherapy. Age, gender, type of surgery, carcinoembryogenic antigen (CEA) level, presence of metastatic disease in one or multiple organs, ypT, ypN, and circumferential resection margin (CRM) were evaluated. Pathologic response of the primary tumor was estimated by using three conventional grading systems and a semiquantitative system assessed by the amount of viable cells out of the total tumor area macroscopically described. Fibrosis, necrosis, and colloid response were evaluated with a semiquantitative system. A complete pathologic response (ypTO) was found in one patient. A good response was observed in the 41.6% of the cases with all grading systems. Presence of fibrosis in the primary tumor was found in six cases. No patient showed CRM involvement. One patient developed a local recurrence. Oxaliplatin-based chemotherapy for stage IV rectal cancer provides high rates of pathologic regression in the rectal tumor and may allow surgery without CRM involvement.

Pathological response may be a better indicator of treatment efficacy than RECIST for patients with mCRC receiving bevacizumab in the neoadjuvant setting. Adding bevacizumab to chemotherapy has the potential to increase pathological response rates. Well-designed prospective clinical studies are required to establish the efficacy and tolerability of this approach.