AbbreviationsCOVID-19 (coronavirus disease 2019), CT (computed tomography), CXR (chest radiograph), RT-PCR (reverse transcriptase-polymerase chain reaction), ICU (intensive care unit), WBC (white blood cell), LDH (lactate dehydrogenase), CRP (C-reactive protein) SummaryVaccinated patients with COVID-19 breakthrough infections showed fewer chest CT findings of pneumonia compared to unvaccinated patients. Key Results1. Of 761 hospitalized patients with COVID-19 disease and chest radiographs, 77% (587/761) were in unvaccinated patients while breakthrough infection in fully vaccinated subjects occurred in 6.2% (47/761) patients.2. The initial chest x-ray showed no pneumonia in 75% of fully vaccinated patients with breakthrough infection and 63% of unvaccinated patients (p=.37).3. In 412 patients with chest CT during hospitalization, a CT showed no pneumonia in 59% of fully vaccinated patients with breakthrough infection and 27% of unvaccinated patients (p=.01).

Mucinous adenocarcinoma is an uncommon type of endometrial adenocarcinoma for which precursor lesions have yet to be clarified. During a review of noncancerous endometrial lesions in postmenopausal women, we found that mucinous endometrial glands showed variable degrees of epithelial changes that ranged from the formation of simple tubular glands to the formation of complex glands with papillary tufts, and some of the glands with papillary tufts were architecturally similar to low-grade mucinous adenocarcinomas. Based on histological similarities, we have postulated that mucinous metaplasia could be a precursor lesion of mucinous adenocarcinoma. To explain the pathogenetic significance of endometrial mucinous metaplasia, we analyzed the immunohistochemical expression of ER, PR, MKI67, PTEN, b-catenin, P16 INK4A , TP53, and PAX2 in 21 endometrial mucinous metaplasias, screened for KRAS (n ¼ 16) and PTEN (n ¼ 14) mutations, and compared expression patterns between samples with simple mucinous glands, those with complex glands having intraglandular papillary tufts, and endometrioid adenocarcinomas. Compared with the surrounding flat mucinous epithelium and simple mucinous metaplasia, the intraglandular papillary tufts associated with papillary mucinous metaplasia were characterized by selectively decreased expression of PAX2 (P ¼ 0.029) and PR (Po0.001), and overexpression of P16 INK4A (P ¼ 0.014). There were no significant differences in the levels of expression of ER, PTEN, b-catenin, TP53, and MKI67 between the two groups. In contrast with endometrioid adenocarcinomas, rates of MKI67 proliferation were very low in both groups. Mutations in KRAS were identified in 89% of cases with papillary mucinous metaplasia, in contrast to 14% in simple mucinous metaplasia (P ¼ 0.001). No PTEN mutations were observed in either of the two groups. In conclusions, immunohistochemical and molecular genetic profiling suggest that papillary mucinous metaplasia is a possible precancerous lesion in a subset of endometrial carcinomas. Modern Pathology (2012Pathology ( ) 25, 1496Pathology ( -1507 doi:10.1038/modpathol.2012; published online 6 July 2012Keywords: endometrium; mucinous; mucinous metaplasia; papillary metaplasia; PAX2; P16 INK4A ; senescence Endometrial carcinoma is classified into two major groups, types I and II, according to clinicopathological features and molecular pathogenetic mechanisms. Most type I tumors are characterized by an endometrioid histology and are frequently associated with PTEN mutations, whereas type II tumors show a serous histology and are frequently associated with the altered expression of TP53 tumor-suppressor genes. Endometrial hyperplasia and endometrial intraepithelial carcinoma are thought to be precursor lesions of type I and II endometrial carcinomas, respectively. However, this simplified classification and their precursor lesions cannot explain the pathogenesis of all endometrial carcinomas.Mucinous adenocarcinoma, an uncommon type of endometrial adenocarcinoma comprising o10% of endometr...

Radiologists must be familiar with the sonographic findings of various diseases involving the superficial layer of the breast to avoid further patient workup.