Detection of SARS-CoV-2 Antigens in the AV-Node of a Cardiac Conduction System-A Case Report.

Mounting evidence indicates that new arrhythmic events frequently occur during and after coronavirus disease (COVID-19), posing additional mortality risk in older-aged and critically ill patients. However, the underlying mechanisms and cardio pathological substrates of COVID-related arrhythmias have not been clarified yet. Here, we report findings of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens and genes in the atrioventricular node (AV-node) of a cardiac conduction system, pointing to its direct infection as a possible arrhythmogenic factor.

Detection of Sars-Cov-2 antigens in thyroid gland showing histopathological features of subacute thyroiditis.

The clinical and laboratory findings of subacute thyroiditis have been repeatedly reported as being associated with acute Sars-Cov-2 infection and post-COVID-19 syndrome. The exact mechanisms and histopathological correlations underlying thyroid involvement remained unresolved, but current insights suggest either direct viral damage, systemic inflammatory reaction, or an autoimmune response as possible noxious effectors. Here we present findings of immunohistochemical/immunofluorescence detection of Sars-Cov-2 viral proteins (spike/S and nucleocapside proteins) in relation to histoarchitectonic changes of autoptic thyroid tissue obtained from patient who deceased from COVID-19.

Osteopontin is associated with decreased apoptosis and αv integrin expression in lung adenocarcinoma.

Osteopontin (OPN) is a glycoprotein involved in invasion, progression and metastasis of many carcinomas. It contains several functional domains including binding sites for αv integrins, cell surface molecules playing a major role in mediating cell migration and adhesion. The aim of the study was to evaluate the expression of osteopontin in human non-small cell lung cancer (NSCLC) and to determine its possible prognostic significance as well as relation to apoptosis and αv integrin expression. We analyzed 111 surgically resected NSCLC for immunohistochemical expression of OPN and αv integrin. OPN expression was compared to apoptotic rate and clinicopathological parameters such as tumor size, histological grade, lymph node status, pT, and TNM stage. Apoptotic rate was measured by TUNEL staining method. OPN expression in NSCLC was significantly higher in lung adenocarcinomas (AC) then in squamous cell carcinomas (p<0.001). There was no correlation between OPN expression and clinicopathological parameters. The level of OPN expression in AC was associated with decreased apoptotic activity of tumor cells (p=0.006), and correlated with αv integrin expression (p=0.048), particularly in low stage tumors (p=0.013). Prolonged tumor cell survival in lung AC due to OPN and αv integrin overexpression may have an impact on tumor progression and resistance to therapy.

Plasmacytoid urothelial carcinoma--diagnostic challenge in cytology.

Plasmacytoid urothelial carcinoma (PUC) is a very rare variant of urothelial carcinoma with an aggressive clinical course. According to small series reported to date, it is a high grade cancer usually diagnosed at an advanced stage, and with poor prognosis. Descriptions of the cytologic features of this type of carcinoma in literature are limited. Plasmacytoid appearance of tumor cells could cause diagnostic dilemma and potential incorrect diagnosis as multiple myeloma (MM). This report describes cerebrospinal fluid, bone marrow, and urine sediment cytomorphologic and immunocytochemical findings in a patient with meningeal carcinomatosis as the first manifestation of a PUC, initially misdiagnosed as MM with a brief review of the literature.

Combined evaluation of bone marrow aspirate and biopsy is superior in the prognosis of multiple myeloma.

BACKGROUND: Estimation of plasma cell infiltrates in bone marrow aspirates (BMA) and bone marrow biopsy (BMB) is a standard method in the diagnosis and monitoring of multiple myeloma (MM). Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of the study was to compare the percentage of plasma cells obtained by both methods with the patient clinical parameters and survival. METHODS: This retrospective study included BMA and BMB of 59 MM patients. The conventional differential count was determined in BMA to estimate the percentage and cytologic grade of plasma cells. The pattern of neoplastic infiltration and percentage of plasma cells were estimated on CD138 immunostained BMB slides microscopically and by computer-assisted image analysis (CIA). RESULTS: Significantly higher values of plasma cell infiltrates were observed in pathologist (47.7 +/- 24.8) and CIA (44.1 +/- 30.6) reports in comparison with cytologist analysis (30.6 +/- 17.1; P < 0.001 and P < 0.0048, respectively). BMB assessment by pathologist counting and using CIA showed strongest correlation (r = 0.8; P < 0.0001). Correlation was also observed between the pathologist and cytologist counts (r = 0.321; P = 0.015) as well as comparing the percentage of plasma cells in BMA and CIA (r = 0.27; P = 0.05). Patients with clinical stage I/II had a significantly lower CIA plasma cell count than those with clinical stage III (P = 0.008). Overall survival was shorter in patients with more than 25% of atypical plasma cell morphology estimated in BMA (P = 0.05) and a higher percentage of tumor cell infiltrates estimated by the pathologist and CIA (P = 0.0341 and P = 0.013, respectively). CONCLUSION: Study results suggested the combined analyses to be useful as a routine procedure to achieve more accurate and informative diagnostic data.

Additional cytomorphological criteria in diagnosis of pilomatricoma--benign tumor with bad reputation.

Pilomatricomas (PM) are benign skin appendageal tumors, with differentiation towards hair-forming cells, usually found in children. They are frequently misdiagnosed by clinicians, and there are also many reports of false positive diagnoses made on fine needle aspiration (FNA) cytology. PM are often mistaken for "small round blue cell" tumors in children, or for Merkel cell carcinoma, basalioma and metastatic small cell carcinoma in adults, with possible over-aggressive therapeutic approach. We present 6 cases of PM, correctly diagnosed preoperatively by FNA. Clinical, cytomorphologic and basic morphometric features were analyzed, and compared with 4 cases of malignant tumors with similar clinical presentation. Morphometric data (longest nuclear diameter) did not prove to be helpful, while basophilic cytoplasmatic protrusions, observed in all 6 analyzed cases, could be useful additional cytomorphologic feature of PM. We concluded that cytomorphologic characteristics of PM are reliable enough for correct preoperative diagnosis in adequate specimens, however the best results are achieved when FNA is performed by an experienced cytologist, and when all relevant clinical data are obtained.

Expression of cell cycle and apoptosis regulatory proteins in keratoacanthoma and squamous cell carcinoma.

Some authors view keratoacanthoma (KA) as a variant of squamous cell carcinoma (SCC), while others consider it a separate entity that must be distinguished from SCC. Involution displayed by KA is an important difference between these two entities. It has been suggested that apoptosis plays a role in the involution process of KA, although the exact trigger for it remains unclear. A hundred and fifty specimens were included in this study, 30 cases for each of the following groups: normal skin (NS), proliferative keratoacanthoma (pKA), regressing keratoacanthoma (rKA), well-differentiated squamous cell carcinoma (wdSCC), and poorly differentiated squamous cell carcinoma (pdSCC). They were immunohistochemically examined for the expression of p53, Ki-67, bak, and bcl-2. Significantly higher p53 and Ki-67 expressions were observed in all tumor lesions examined as compared with NS. There was higher bak expression in KAs compared to NS and a significant reduction of bak expression in pdSCC together with a significant reduction of bak expression in SCCs compared to pKA. Bcl-2 expression was similar in NS and SCCs, but was lower in rKA. We found a significant positive correlation between p53 and Ki-67, p53 and Bak in NS and examined skin tumors. Lower bcl-2 expression in conjunction with higher bak expression in rKA suggests a possible role of these apoptosis-regulating proteins in tumor regression. In contrast to this finding, a steady level of bcl-2 expression in pdSCC combined with lower bak expression levels and a high proliferation rate could contribute to progression and aggressiveness in these tumors. Bak and p53 expression is a sun-related and age-dependent process in NS and skin tumors.