SARS-CoV-2's high rate of genetic mutation under immune selective pressure: from oropharyngeal B.1.1.7 to intrapulmonary B.1.533 in a vaccinated patient.

This is the case report of an 84-year-old man affected by COVID-19 between the 2 doses of vaccination, with negative exitus. We analyzed nasopharyngeal samples of viral RNA collected during the disease and nasopharyngeal and lung samples collected postmortem by reverse transcription LAMP (RT-LAMP) PCR and Next Generation Sequencing (NGS). NGS results were analyzed with different bioinformatic tools to define virus lineages and the related single-nucleotide polymorphisms (SNPs). Both lung and nasopharyngeal samples tested positive for SARS-CoV-2 on RT-LAMP. Through bioinformatic analysis, 2 viral RNAs from the nasal swabs, which belonged to the B.1.1.7 lineage, and 1 viral RNA from the lung sample, which belonged to the B.1.533 lineage, were identified. This genetic observation suggested that SARS-CoV-2 tends to change under selective pressure. The high mutation rate of ORFa1b, containing a replicase gene, was a biological image of a complex viral survival system.

Dystrophin and metalloproteinase 9 in myocardial ischemia: A post-mortem immunohistochemical study.

The presented study evaluated the expression of dystrophin and MMP-9 in cases of sudden cardiac death (SCD) due to coronary atherosclerotic disease (CAD) in order to analyze the characteristics and the chronology of their expression, providing evidence on the possible role in post-mortem diagnosis of myocardial ischemia. The expression of these proteins was also compared to C5b-9 complex and fibronectin expression to evaluate any differences. Two groups of CAD-related SCD, respectively group 1 with gross and/or histological evidence and group 2 with no specific histological signs of myocardial ischemia, were used. A third group formed by cases of acute mechanical asphyxiation was used as a control. The immunohistochemical staining by dystrophin, MMP-9, C5b-9, and fibronectin antibodies was performed. The study revealed that dystrophin and MMP-9 showed different expression in group 1 and group 2 as, respectively, different degree of sarcolemmal staining depletion and increasing of interstitial and granulocytes immunopositivity. Moreover, loss of dystrophin staining and C5b-9 immunopositivity were more significant when compared to MMP-9 increasing. Dystrophin and MMP-9 seemed to be useful immunohistochemical markers for the detection of myocardial ischemic damage. However, the comparison of the four markers suggested that loss of dystrophin could be considered as an earlier marker.

Wilms' Tumor 1 (WT1): A Novel Immunomarker of Dermatofibrosarcoma Protuberans-An Immunohistochemical Study on a Series of 114 Cases of Bland-Looking Mesenchymal Spindle Cell Lesions of the Dermis/Subcutaneous Tissues.

PURPOSE: to investigate the immunohistochemical expression and distribution of Wilms' tumor 1 (WT1) (transcription factor produced by the tumor suppressor gene of the same name) in a series of 114 cases of bland-looking mesenchymal spindle cell lesions of the dermis/subcutaneous tissues to establish whether this immunomarker is differentially expressed in dermatofibrosarcoma protuberans (DFSP) versus its potential morphological mimickers. METHODS: This retrospective multi-centric immunohistochemical study included 57 DFSP cases, 15 dermatofibromas, 5 deep fibrous histiocytomas, 8 neurofibromas, 5 spindle cell lipomas, 8 dermal scars, 6 nodular fasciitis, 5 cutaneous leiomyomas and 5 solitary fibrous tumors. Among the 57 DFSP cases, 11 were recurrent lesions; 2 non-recurrent cases exhibited an additional "fibrosarcomatous" overgrowth and 1 recurrent and 2 primary tumors contained a minority of "giant cell fibroblastoma" components. RESULTS: Most DFSP (95% of cases) exhibited cytoplasmic staining for WT1; 11/11 residual/recurrent tumors showed diffuse and strong WT1 cytoplasmic immunoreactivity; apart from neurofibromas, WT1 expression was lacking in all the other cases studied. CONCLUSIONS: The cytoplasmic expression of WT1 may be exploitable as a complementary diagnostic immunomarker to CD34 in confirming the diagnosis of DFSP and to better evaluate the residual/recurrent tumor component.

Cell differentiation in cardiac myxomas: confocal microscopy and gene expression analysis after laser capture microdissection.

Cardiac myxomas are rare tumors with a heterogeneous cell population including properly neoplastic (lepidic), endothelial and smooth muscle cells. The assessment of neoplastic (lepidic) cell differentiation pattern is rather difficult using conventional light microscopy immunohistochemistry and/or whole tissue extracts for mRNA analyses. In a preliminary study, we investigated 20 formalin-fixed and paraffin-embedded cardiac myxomas by means of conventional immunohistochemistry; in 10/20 cases, cell differentiation was also analyzed by real-time RT-PCR after laser capture microdissection of the neoplastic cells, whereas calretinin and endothelial antigen CD31 immunoreactivity was localized in 4/10 cases by double immunofluorescence confocal microscopy. Gene expression analyses of α-smooth muscle actin, endothelial CD31 antigen, alpha-cardiac actin, matrix metalloprotease-2 (MMP2) and tissue inhibitor of matrix metalloprotease-1 (TIMP1) was performed on cDNA obtained from either microdissected neoplastic cells or whole tumor sections. We found very little or absent CD31 and α-Smooth Muscle Actin expression in the microdissected cells as compared to the whole tumors, whereas TIMP1 and MMP2 genes were highly expressed in both ones, greater levels being found in patients with embolic phenomena. α-Cardiac Actin was not detected. Confocal microscopy disclosed two different signals corresponding to calretinin-positive myxoma cells and to endothelial CD31-positive cells, respectively. In conclusion, the neoplastic (lepidic) cells showed a distinct gene expression pattern and no consistent overlapping with endothelial and smooth muscle cells or cardiac myocytes; the expression of TIMP1 and MMP2 might be related to clinical presentation; larger series studies using also systematic transcriptome analysis might be useful to confirm the present results.

Immunohistochemical study on dystrophin expression in CAD-related sudden cardiac death: a marker of early myocardial ischaemia.

The aims of this study were to assess if dystrophin can be a tool for the forensic evaluation of sudden cardiac death due to coronary atherosclerotic disease (CAD) and particularly if it can be a marker of early myocardial ischaemia. Then in this investigation, the dystrophin was compared to C5b-9 and fibronectin to analyze if there are some differences in the expression of these proteins. Two groups of CAD-related sudden cardiac death, respectively the group 1 with gross and/or histological evidence and the group 2 with no specific histological signs of myocardial ischaemia were used. A third group formed by cases of acute mechanical asphyxiation was used as a control. The immunohistochemical staining by dystrophin, C5b-9 and fibronectin antibodies was performed. Loss of sarcolemmal dystrophin was observed in different degrees according to more or less significant histological evidence of myocardial ischaemia. Moreover, the comparison between loss of dystrophin expression and fibronectin positivity showed significant differences in group 2. The results suggested that dystrophin can be used in forensic diagnosis of CAD-related sudden cardiac death and as marker of early myocardial ischaemia.

Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association For European Cardiovascular Pathology: II. Noninflammatory degenerative diseases - nomenclature and diagnostic criteria.

Surgical aortic specimens are usually examined in Pathology Departments as a result of treatment of aneurysms or dissections. A number of diseases, genetic syndromes (Marfan syndrome, Loeys-Dietz syndrome, etc.), and vasculopathic aging processes involved in vascular injury can cause both distinct and nonspecific histopathologic changes with degeneration of the media as a common denominator. Terminology for these changes has varied over time leading to confusion and inconsistencies. This consensus document has established a revised, unified nomenclature for the variety of noninflammatory degenerative aortic histopathologies seen in such specimens. Older terms such as cystic medial necrosis and medionecrosis are replaced by more technically accurate terms such as mucoid extracellular matrix accumulation (MEMA), elastic fiber fragmentation and/or loss, and smooth muscle cell nuclei loss. A straightforward system of grading is presented to gauge the extent of medial degeneration and synoptic reporting tables are provided. Herein we present a standardized nomenclature that is accessible to general pathologists and useful for future publications describing these entities.

Takotsubo cardiomyopathy associated with rupture of the left ventricular apex: assessment of histopathological features of a fatal case and literature review.

Takotsubo cardiomyopathy, also known as "broken heart syndrome," is a cardiac entity characterized by transient left ventricular dysfunction without obstructive atherosclerotic coronary artery disease. An episode of emotional stress is believed to act as a trigger in the development of this syndrome, which typically occurs in female patients. We report a fatal case of a previously healthy 70-year-old woman who suffered an out-of-hospital cardiac arrest and cardiac rupture during emotional distress, due to Takotsubo cardiomyopathy. Ventricular rupture with Takotsubo cardiomyopathy is rare, but our case emphasizes the importance of dealing with this serious and potentially life-threatening disease. Takotsubo cardiomyopathy should be considered as a differential diagnosis in cases of early-developing heart failure, and clinicians should subsequently use adequate diagnostic and therapeutic options.

Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases.

Inflammatory diseases of the aorta include routine atherosclerosis, aortitis, periaortitis, and atherosclerosis with excessive inflammatory responses, such as inflammatory atherosclerotic aneurysms. The nomenclature and histologic features of these disorders are reviewed and discussed. In addition, diagnostic criteria are provided to distinguish between these disorders in surgical pathology specimens. An initial classification scheme is provided for aortitis and periaortitis based on the pattern of the inflammatory infiltrate: granulomatous/giant cell pattern, lymphoplasmacytic pattern, mixed inflammatory pattern, and the suppurative pattern. These inflammatory patterns are discussed in relation to specific systemic diseases including giant cell arteritis, Takayasu arteritis, granulomatosis with polyangiitis (Wegener's), rheumatoid arthritis, sarcoidosis, ankylosing spondylitis, Cogan syndrome, Behçet's disease, relapsing polychondritis, syphilitic aortitis, and bacterial and fungal infections.

Unexpected death for Takayasu aortitis associated with coronary ostial stenosis: case report.

The differential diagnosis of vasculitis is often a difficult task due to the frequent morphological similarities that various vasculitic syndromes express when the heart is the target organ. The more the lesions are limited to the arterial tree with absent or almost silent coronary events, the less specific the anatomical and clinical frameworks. To create a series of clinical records and on the basis of these assumptions, the authors report a case concerning the sudden death of a 43-year-old woman which occurred while an ergonometric test was being carried out 28 days after the onset of the symptoms. A subsequent postmortem investigation/autopsy enabled us to detect a granulomatous aortitis process and, in particular, a coronary ostial stenosis and severe involvement of the coronary vessels which was compatible with the pathological framework of Takayasu disease.

Fatal accidental ingestion of 35 % hydrogen peroxide by a 2-year-old female: case report and literature review.

Deaths after ingestion of hydrogen peroxide (HP) are very rare, but poisoning due to consumption of HP is not uncommon. Most HP exposure involves common household-strength (3 %) HP and is usually benign. Even if it is not generally considered to be a poison, it can cause accidental death. HP results in morbidity through two main mechanisms: direct cytotoxic injury to tissues and formation of oxygen gas. We describe a rare case of a 2-year-old female who died after accidentally ingesting two sips of 35 % HP. For the first time, we provide histopathological images of the damage caused by HP in organic tissues.

A fatal stab wound causing selective injury to the left anterior descending coronary artery, myocardial infarction and delayed cardiac tamponade.

We describe an unusual case of delayed cardiac tamponade that led to death 9 days after a penetrating stab wound. The injury consisted of a longitudinal tear in the LAD coronary artery, with an occlusive thrombus and the rupture of the coronary wall into a pseudo-aneurysmatic peri-coronary hematoma. As imaging evidence of pericardial effusion and ischemic electrocardiographic changes were lacking, the diagnosis was only made during post-mortem examination.

Functional mitral regurgitation: from normal to pathological anatomy of mitral valve.

Mitral valve (MV) is composed of several structures working in synchrony to open during diastole and close in systole within the high-pressure systemic environment. Its morphological features ensure a normal leaflet closure that prevents regurgitation of blood back into the left atrium causing loss of ventricular pressure and forward flow. The complex interactions of the normal MV are reliant on each component playing a complete role for the efficient working of the valve. In this review we firstly discuss the overall MV structure in terms of a complex make up of the annulus, the leaflets, their tendinous cords, and the supporting papillary muscles, and then the anatomical changes of each MV components due to left ventricular geometry and function alterations, underlying functional mitral regurgitation.

Apoptosis in temporomandibular joint disc with internal derangement involves mitochondrial-dependent pathways. An in vivo study.

OBJECTIVE: Two main apoptosis pathways have been identified: an extrinsic (or death receptor-mediated) and an intrinsic (or mitochondrial) pathway. Apoptotic cell death through the extrinsic pathway has just been described in temporomandibular joint disc (TMJ) with internal derangement (ID); in contrast, no data are available on the involvement of the intrinsic pathway in this tissue. The aim of this work was to investigate whether the intrinsic pathway participates in apoptosis activation in patients with TMJ ID and anterior disc displacement without reduction. MATERIALS AND METHODS: Apoptosis activation was studied in TMJ discs from 15 patients with ID and in six unaffected discs using bcl-2-associated X protein (bax), B-cell lymphoma 2 (bcl-2), cytochrome c and caspase 9 immunohistochemistry. A correlation was sought between immunohistochemical findings and degree of disc damage. RESULTS: None of the pathological TMJ disc sections were immunopositive for bcl-2; negative bcl-2 immunostaining was detected in affected discs; cytochrome c and caspase 9 immunoreactivity was greater in pathological compared to unaffected discs; the difference was significant and correlated with histopathological degeneration score data (Spearman's rho = 0.617). CONCLUSION: The present findings suggest that in-human TMJ with ID and anterior disc displacement without reduction of cell apoptosis occurs, at least partly, via the mitochondrial pathway, which contributes to the subsequent disc degeneration. These data may have clinical implications and could help devise improved treatment strategies.

Incidental Epstein-Barr virus associated atypical lymphoid proliferation arising in a left atrial myxoma: a case of long survival without any postsurgical treatment and review of the literature.

We report a case of left atrial cardiac myxoma harbouring an incidental atypical B-cell lymphoid proliferation. Histology disclosed classic myxoma cells embedded in a mucopolysaccharide-rich matrix and a micronodular atypical lymphoid proliferation under the surface of the mass. Myxoma cells were immunoreactive for calretinin, while lymphoid cells expressed B lineage markers (CD 20+, CD79a), without evidence of clonality. Moreover, they were LMP1 positive; EBNA2 negative; KSHV/HHV8 negative; and, by in situ hybridization, EBER/Epstein-Barr virus (EBV) positive and Kappa and Lambda negative. According to the 2008 WHO schemes, the present case shares close similarities either with diffuse large B-cell lymphomas growing in the context of long-standing chronic inflammation or with primary effusion lymphomas, solid variant, both associated with EBV infection. This is the sixth case of incidental atypical lymphoid proliferation discovered in a cardiac myxoma reported so far. The optimal treatment of such lesions remains undefined, but their clinical course is indolent. After an accurate staging workup, without any postsurgical treatment, the patient we observed has been well with no recurrence of the disease at 6 years of follow-up.

Life-threatening tumors of the heart in fetal and postnatal age.

OBJECTIVES: To evaluate the role of histology in diagnosis and management of biologically benign heart tumors causing life-threatening symptoms and even death in children and fetuses. The clinical impact of a multidisciplinary approach including 2-D echocardiography, histology, genetics, and cardiac surgery has not yet been fully elucidated. STUDY DESIGN: Forty-one consecutive antenatal (n = 17) or postnatal (n = 24) detected cardiac masses were evaluated by 2-D echocardiography (in alive patients) or at autopsy, and 12/41 cases with definite histologic diagnosis of primary and benign cardiac tumor were entered in this study. RESULTS: Rhabdomyomas (n = 6), hemangiomas (n = 3), central fibrous body chondroma (n = 1), fibroma (n = 1), or left atrial myxoma (n = 1) were histologically diagnosed in 4 fetuses and in 8 children. Death occurred in 6 patients showing diffuse or infiltrative tumors, 2/6 experiencing intrauterine death or sudden and unexpected infant death. Seven patients underwent surgery, 4/7 are alive and well at >5 years follow-up, whereas 3 deaths followed partial tumor resection. Two fetuses with extensive tumor/s were aborted. Tuberous sclerosis complex gene mutations were seen in patients with rhabdomyomas. CONCLUSIONS: Histology represents the best diagnostic approach in life-threatening pediatric cardiac tumors allowing definite diagnosis in cases other than rhabdomyoma and in sudden deaths, influencing clinical management and counselling. 2-D echocardiography remains the main tool for early clinical diagnosis and follow-up. A multidisciplinary approach is advisable because of rarity, difficult management, and possible associations with inheritable diseases.