Aims
Gastric dysplasia is a risk factor for synchronous and subsequent gastric carcinoma. Distinguishing gastric dysplasia from reactive changes is subject to interobserver disagreement and is a frequent reason for expert consultation. We previously used assessment of surface cell polarity (the ‘four lines’) as a key feature to decrease equivocal diagnoses in Barrett oesophagus. In the current study, we examined for the presence or absence of the four lines in gastric dysplasia and reactive gastropathy.
Materials and methods
The study includes all (n = 91) in‐house biopsies with at least gastric dysplasia from the surgical pathology archives of two academic institutions during a 5‐year period from 2008 to 2012. A reactive gastropathy group (n = 60) was created for comparison.
Results
The dysplasia/neoplasia group was comprised of 14 biopsies of gastric foveolar‐type dysplasia, 59 of intestinal‐type dysplasia, 14 with dysplasia in fundic gland polyps, three pyloric gland adenomas and one oxyntic gland adenoma. Loss of surface cell polarity was seen in all 88 dysplasia cases with evaluable surface epithelium. All 57 reactive gastropathy cases with evaluable surface epithelium showed intact surface cell polarity except in focal areas directly adjacent to erosions in 17 cases, where the thin wisp of residual surface mucin could not be appreciated on haematoxylin and eosin.
Conclusion
Surface cell polarity (the four lines) was lost in all gastric dysplasia biopsies with evaluable surface epithelium and maintained in all biopsies of reactive gastropathy. Caution should be taken in using this feature adjacent to erosions in reactive gastropathy.
Digital papillary adenocarcinoma (DPA) is a rare neoplasm that can exhibit local recurrence and distant metastasis. We present a series of eight cases of DPA showing two distinct clinical presentations, morphologies, immunophenotypes, and molecular features.Four cases were characterized by painless, slow-growing nodules located on the digits.The lesions were small, well-defined, and confined in the dermis. Histopathologically, these tumors were composed of glandular structures lined by cuboidal epithelium with luminal papillary infoldings. Only rare mitotic figures and minimal squamoid differentiation were present, and cellular necrosis was absent. All four cases were positive for the BRAF V600E immunohistochemistry but negative for p16, low-risk and high-risk HPV in situ hybridization (ISH). In contrast, the remaining four cases were characterized by painful, rapidly growing masses on the digits. These four lesions were located in the deep dermis and consisted of a solid, tightly packed papillary architecture lined by atypical epithelioid cells with inconspicuous nucleoli. Cellular necrosis, numerous mitotic figures, and prominent squamoid differentiation were seen. All cases were negative for the BRAF V600E IHC. However, they showed strong, patchy to diffuse reactivity for p16 and were positive for low-risk HPV ISH and negative for high-risk HPV ISH. Our findings suggest that the current classification of DPA encompasses tumors that show two discrete pathogenic pathways -BRAF mutation or low-risk HPV infection. DPAs with low-risk HPV infection exhibit aggressive clinical features, high-grade morphology, marked squamoid differentiation, and wild-type BRAF. DPAs with BRAF V600E have less aggressive clinical features, low-grade morphologic findings, mild to absent squamoid differentiation, and negative HPV infection.
The SARS-CoV-2 variant, B.1.1.519, arose in North and Central America, circulating primarily in
Mexico. We demonstrate that this variant peaked during the second wave of COVID-19 in
Mexico City in the spring of 2021. This variant is likely more infectious, attributed to mutation in
the RBD of the spike protein T478K also seen in the alpha variant (B.1.1.7). However the time
dynamics of the spread of this variant drastically changed upon the introduction of delta
(B.1.617.2) to the country in which we observe a shift from 0% in May 2021 to 55% delta in the
span of one month. Since the delta variant has dominantly spread across the globe, we
investigated the increasing frequency of the Mexico variant , B.1.1.519, in the public community
within Mexico City. Once present, the delta variant was 78% of the Mexico City catchment in
July 2021, a time which marked the commencement of Mexicos third wave. Our data supports
the growing concern that the delta variant is closely associated with the massive infection
spread of the VOC in Central and South America. While the T478K mutation, also seen in the
alpha variant, has evidence for increased transmissibility, these data suggest that the delta
variant shows overall increased fitness seeing as it outcompeted the B.1.1519 this Mexico
community.
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