The aim of the present study was to classify colorectal carcinoma (CRC) into molecular subtypes, based on immunohistochemical (IHC) assessments. A total of 112 CRC samples were molecularly classified based on the expression levels of epithelial-mesenchymal transition (EMT)-associated IHC markers. A total of three molecular subtypes were defined: Epithelial, membrane positivity for E-cadherin and β-catenin, negative for vimentin; mesenchymal, E-cadherin-negative, nuclear β-catenin-and vimentin-positive; and hybrid cases, epithelial tumor core and mesenchymal tumor buds. Most of the cases were diagnosed as moderately differentiated adenocarcinoma (n=89; 79.46%). The majority of cases (n=100; 89.28%) exhibited a mismatch repair proficient status (microsatellite stable CRCs). A predominance of epithelial-type (n=51; 45.54%) and hybrid CRCs (n=47; 41.96%) was observed, whereas a few cases (n=14; 12.50%) were classified as mesenchymal-type CRCs. This molecular classification was associated with pathological stage (P<0.01), pT stage (P=0.04), pN stage (P<0.01), the grade of tumor budding (P=0.04), and maspin expression in both the tumor core (P=0.04) and the invasion front (P<0.01). The mesenchymal-type cases predominantly exhibited lymph node metastases, high-grade budding and a tendency towards maspin nuclear predominance. All epithelial-type cases with maspin-only expression (n=18) were non-metastatic. Patients with CRC of the epithelial subtype and those with a lymph node ratio (LNR) ≤0.15 presented the best overall survival, followed by those with hybrid and mesenchymal subtypes. Nuclear maspin positivity was more frequent in cases with a high-budding degree compared with those with a low-budding degree (P=0.03). The EMT-associated molecular classification of CRCs may be used to identify the most aggressive CRCs, which show a mesenchymal phenotype, high-budding degree, maspin nuclear positivity and lymph node metastases. The pN stage, LNR and budding degree of patients, which can be evaluated with maspin expression, remain the most important prognostic factors.

Background. Plasmacytoid urothelial carcinoma is a rare and aggressive histologic variant of high-grade carcinoma of the urinary bladder. Few than 250 cases have been reported in the urinary bladder till January 2019. In this paper, a case series of unusual gastrointestinal carcinomas with plasmacytoid morphology was included. Only one similar case of the stomach was previously published and no such cases were found in colon. Methods. We present the complex immunoprofile, using a panel of 39 biomarkers, of the largest group of primary gastrointestinal carcinomas with plasmacytoid morphology reported in literature (one from upper rectum and six from stomach). Results. All of the seven cases showed lymph node metastases and only one survived over 25 weeks after surgical excision. The indicators of aggressivity were age (over 60), advanced stage (from IIIA to IV), E-cadherin negativity, and vimentin positivity. The immunoprofile indicated unfavorable prognosis for mesenchymal-type carcinomas (negativity for E-cadherin and positivity for vimentin, with membrane to nuclear translocation or negativity of β-catenin). The survivor showed an “epithelial-type adenocarcinoma with plasmacytoid dedifferentiation”, with membrane positivity for E-cadherin and β-catenin and vimentin negativity. All of the cases expressed c-MET and were negative for HER-2. Conclusions. Primary carcinoma with plasmacytoid morphology is a dedifferentiated variant of adenocarcinoma or poorly cohesive carcinomas. Vimentin positive dedifferentiated-poorly cohesive carcinomas should be considered as mesenchymal-type highly malignant carcinomas. This rare histologic variant of gastrointestinal cancer might respond to anti-c-MET tyrosine kinases.

BACKGROUND Although hepatocellular carcinoma (HCC) is one of the most vascular solid tumors, antiangiogenic therapy has not induced the expected results. AIM To uncover immunohistochemical (IHC) aspects of angiogenesis in HCC. METHODS A retrospective cohort study was performed and 50 cases of HCC were randomly selected. The angiogenesis particularities were evaluated based on the IHC markers Cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) A and the endothelial area (EA) was counted using the antibodies CD31 and CD105. RESULTS The angiogenic phenotype evaluated with VEGF-A was more expressed in small tumors without vascular invasion (pT1), whereas COX-2 was rather expressed in dedifferentiated tumors developed in non-cirrhotic liver. The CD31-related EA value decreased in parallel with increasing COX-2 intensity but was higher in HCC cases developed in patients with cirrhosis. The CD105-related EA was higher in tumors developed in patients without associated hepatitis. CONCLUSION In patients with HCC developed in cirrhosis, the newly formed vessels are rather immature and their genesis is mediated via VEGF. In patients with non-cirrhotic liver, COX-2 intensity and number of mature neoformed vessels increases in parallel with HCC dedifferentiation.

In the COVID-19 era, patients with severe acute respiratory syndrome (SARS) are suspected to be associated with SARS-CoV-2 infection. The aim of this paper is to present a case with COVID-like pneumonia, with fatal evolution. The clinical aspects were correlated with the autopsy findings and discussed on the background of the most recent data from the medical literature. A 13-month-old girl was admitted to the emergency room with acute severe shortness of breath and pulmonary bilateral ground-glass opacities and an almost complete opacified left lung. The patient suddenly deteriorated, and death was confirmed 3 h after admission. At autopsy, severe desquamative interstitial pneumonia was diagnosed and was associated with an unusual IgA glomerulonephritis. No SARS-CoV-2 infection was detected in the lung parenchyma by RT- PCR. This is a very unusual case of rapid deterioration of an infant with idiopathic desquamative interstitial pneumonia (IDP) and multiorgan involvement. Based on immunohistochemical stains, we hypothesize that, in IDP, the hyaline membranes arise from necrotizing desquamated pneumocytes. In the COVID-19 era, such cases are extremely difficult to diagnose; they can mimic SARS-CoV-2-induced lung injuries. This pattern of hyaline membrane formation might explain the poor response to oxygen therapy. The present case highlights the importance of autopsy in such challenging cases.

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