In this study, we compared the incidence of pneumomediastinum in coronavirus disease (COVID-19) patients during the ascending phases of the 1 st and 2 nd epidemic waves. Crude incidence was higher during the 2 nd wave at a quasi-significant level (0.68/1000 vs. 2.05/1000 patient-days, p = 0.05). When restricting the analysis to patients who developed pneumomediastinum during noninvasive ventilation, the difference became clearly significant (0.17/1000 vs 1.36/1000 patient-days, p = 0.039). At logistic regression, predisposing factors (p = 0.031), and COVID-19 radiological severity (p = 0.019) were independently associated with pneumomediastinum. Mortality in patients with pneumomediastinum was 87.5%. However, pneumomediastinum seemed to be related to a generally worse disease presentation in hospitalized patients during the 2 nd wave, rather than to a separate pattern of disease.

A 42-year-old woman with a proliferating tricholemmal tumour (PTT) with regional lymph node metastases is reported. Histochemical studies showed evidence of tricholemmal keratinization. There was recurrence following excision and subsequently the patient developed lymph node metastases.

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Hereditary angioedema (HAE) is a disease related to a complement disorder, namely a deficiency of C1 esterase inhibitor. Complement-split products are implicated in the regulation of the immune response, and we have compared some immunologic parameters between HAE and normal individuals. T-lymphocytes with receptors for IgG were increased in HAE, but no difference in T-cell suppressor activity for B-cells was detected. Furthermore, increased IgG receptor expression was not accompanied by any significant changes in the ratios of OKT4- and OKT8-defined antigens. Numbers of peripheral mononuclear cells (MNC) detected by alpha-naphthyl acetate esterase (ANAE) staining positivity were not significantly modified in HAE patients, although there was a trend toward higher absolute numbers of them showing paranuclear localization of ANAE. HAE patients had significantly reduced numbers of Langerhans cells (LC) showing different morphology and localization patterns. These observations are discussed in terms of differential membrane arrangements related to particular stages of cell activation, possibly attributable to continual complement activation resulting from a lack of control by C1 esterase inhibitor.