Pathological diagnosis of Coronavirus-related nephropathy: insight from postmortem studies.

A novel coronavirus pneumonia first occurred in Wuhan, China in early December 2019; the causative agent was identified and named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the World Health Organization (WHO), and the resulting disease termed coronavirus disease 2019 (COVID-19), according to the WHO coronavirus disease situation reports. This condition has spread rapidly all over the world and caused more than 125 million cases globally, with more than 2 million related deaths. Two previous outbreaks due to zoonotic coronaviruses have occurred in the last 20 years, namely the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), causing high morbidity and mortality in human populations upon crossing the species barriers. SARS-CoV-2, SARS-CoV, and MERS-CoV show several similarities in pathogenicity and clinical presentations, the latter ranging from asymptomatic infection to severe acute respiratory distress syndrome (ARDS) and multiorgan impairment. Acute kidney injury (AKI) has been commonly reported in patients with CoV infections; therefore, pathological analysis of renal parenchyma in these patients has been carried out in order to improve knowledge about underlying mechanisms. Viral infection has been demonstrated in the renal tubular epithelial cells by electron microscopy (EM), immunohistochemistry (IHC), and in situ hybridization (ISH), although with conflicting results. Light microscopy (LM) changes have been described in the renal parenchyma primarily in the form of acute renal tubular damage, possibly due to direct viral cytopathic effect and immune-mediated mechanisms such as cytokine storm syndrome. In this review, we describe and discuss the spectrum of histological, ultrastructural, and molecular findings in SARS-CoV, MERS-CoV, and SARS-CoV-2-related renal pathology obtained from postmortem studies, as well as intrinsic limitations and pitfalls of current diagnostic techniques.

Germinotropic lymphoproliferative disorder: a systematic review.

Germinotropic lymphoproliferative disorder is a rare and rather enigmatic novel entity with distinctive clinicopathological features, one of which is the typical co-infection by Human herpesvirus 8 and Epstein-Barr virus. Human herpesvirus 8 is a lymphotropic virus detected in Kaposi sarcoma, multicentric Castleman disease, primary effusion lymphoma, Human herpesvirus 8-positive diffuse large B cell lymphoma not otherwise specified, and germinotropic lymphoproliferative disorder. Co-infection by Human herpesvirus 8 and Epstein-Barr virus is identified only in two lymphoproliferative diseases: germinotropic lymphoproliferative disorder and primary effusion lymphoma, which are otherwise diseases with totally different clinical presentations and outcomes. Unlike primary effusion lymphoma mostly occurring in immunocompromised individuals and following an aggressive course, germinotropic lymphoproliferative disorder usually presents with single or multiple lymphadenopathy affecting mainly immunocompetent individuals and mostly follows an indolent course. Based on the PRISMA guidelines, we carried out a systematic search on PubMed/MEDLINE, Web of Science, Scopus, EMBASE, and Cochrane Library using the search terms "germinotropic" and "lymphoproliferative disorder." Current scientific literature reports just 19 cases of germinotropic lymphoproliferative disorder. The purpose of our systematic review is to improve our understanding of the disease, focusing on epidemiology, clinical presentation, pathological features, treatment, and outcome. In addition, we discuss the differential diagnosis with the other Human herpesvirus 8-related lymphoproliferative diseases as currently recognized in the World Health Organization classification, adding a focus on lymphoproliferative disorders showing overlapping features.

Extracranial metastases in secondary glioblastoma multiforme: a case report.

BACKGROUND: Glioblastoma (GBM) is known for its devastating intracranial infiltration and its unfavorable prognosis, while extracranial involvement is a very rare event, more commonly attributed to IDH wild-type (primary) GBM evolution. CASE PRESENTATION: We present a case of a young woman with a World Health Organization (WHO) grade II Astrocytoma evolved to WHO grade IV IDH mutant glioblastoma, with subsequent development of lymphatic and bone metastases, despite the favorable biomolecular pattern and the stability of the primary brain lesion. CONCLUSIONS: Our case highlights that grade II Astrocytoma may evolve to a GBM and rarely lead to a secondary metastatic diffusion, which can progress quite rapidly; any symptoms referable to a possible systemic involvement should be carefully investigated.

Primary histiocytic sarcoma presenting as diffuse leptomeningeal disease: Case description and review of the literature.

Histiocytic sarcoma is a rare malignant neoplasm arising most commonly in lymph nodes, intestinal tract, skin and soft tissue. The incidence of primary CNS histiocytic sarcoma is even rarer with a total of just 27 cases reported in the literature so far. Herein we describe the first autopsy case of histiocytic sarcoma presenting as a diffuse leptomeningeal disease in absence of a CNS tumor-forming parenchymal lesion. The clinical, pathological and immunophenotypic features are described and an updated literature review on primary CNS histiocytic sarcoma is included.

When biopsy alone is not enough for the diagnosis: angiomatous florid proliferation hiding a merkel cell carcinoma.

Merkel cell carcinoma (MCC) is an aggressive tumor with an uncertain histogenesis typically arising on sun-damaged skin of the elderly. It has rarely been described in association with other tumors such as epithelial, melanocytic, and mesenchymal, but not vascular neoplasias. However, an exuberant vascular reaction is considered a common phenomenon in neuroendocrine neoplasms, where it can even obscure the proliferating cells and mimic a primary vascular neoplasia. A 47-year-old man was referred for the evaluation of a long-lasting reddish skin tumor located on the right buttock. After 2 punch biopsies, the patient underwent surgical excision of the lesion. Histological examination showed a dermal florid, benign vascular proliferation overlying some large deep coalescent nodules made up of monomorphous round cells with scant cytoplasm and a high mitotic activity. After the appropriate immunohistochemical stainings, a final diagnosis of hemangioma overlying a previously unrecognized MCC was rendered. Whether the angiomatous proliferation should be considered an exuberant reaction to the tumor, induced by an angiogenetic drive, or a true hemangioma is somewhat controversial. The main point is that such a neoplastiform angiomatous proliferation may represent a potential diagnostic pitfall, especially in limited specimens, and that an accurate clinicopathologic correlation is always needed. In our case, even if additional punch biopsies had been performed, the vascular proliferation would dominate the histological picture and an accurate diagnostic conclusion would probably not be reached due to the deep location of the MCC.

Role of magnetic resonance imaging in differentiating intrasellar cavernous hemangioma and pituitary adenoma: A case report-Decipit frons prima multos.

BACKGROUND: Cavernous hemangioma represents a rare vascular malformation usually located in the cavernous sinus that could be exceptionally found purely in the intrasellar region. The clinical presentation of intrasellar cavernous hemangioma (ICH), frequently variable and unspecific, poses the patient at risk for misdiagnosis and the clinical consequences of suboptimal treatment. We present a case of ICH and describe the advanced magnetic resonance imaging (MRI) features that should direct toward the clinical suspicion of ICH. CASE PRESENTATION: An illustrative case of a 61-year-old man complaining of recurrent headaches and diagnosed with a sellar and parasellar lesion was reported and used as a cue to discuss MRI imaging sequences that may aid in the distinction of ICH from pituitary adenoma and other skull base lesions. Heterogeneous enhancement followed by intense homogeneous enhancement at the dynamic contrast-enhanced sequences ("fill-in" phenomenon), absence of blooming signs at the gradient recalled echo (GRE) T2*-weighted and/or susceptibility-weighted imaging (SWI) MRI sequences, and elevated apparent diffusion coefficient (ADC) values usually characterize ICH instead of pituitary adenoma. CONCLUSION: Advanced MRI imaging plays an invaluable role in the pre-operative characterization of skull base lesions. Although rare, skull base surgeons should be aware of the ICH in the differential diagnosis process in case of the intrasellar lesion, and a tailored MRI examination should be performed to direct the patient toward the safest and optimal treatment.

Primary Diffuse Large B-Cell Lymphoma of the Urinary Bladder: Update on a Rare Disease and Potential Diagnostic Pitfalls.

Diffuse large B-cell lymphoma (DLBCL) represents the most frequent type of non-Hodgkin lymphoma. Globally, DLBCL is an aggressive disease, requiring an accurate diagnosis and prompt treatment. The diagnosis is often made on biopsy samples of a nodal mass, however, approximately 40% of DLBCL cases arise at extranodal sites. The most common extranodal site is the gastrointestinal tract, however any extranodal area may be primarily involved. Primary urinary bladder lymphoma represents only 0.2% of extranodal non-Hodgkin lymphomas, whereas secondary involvement of the urinary bladder by a systemic lymphoma is a more common event. Despite being rare, DLBCL is considered to represent the predominant primary urinary bladder lymphoma. The majority of cases reported in the bladder belong to the DLBCL, NOS group, and there are only rare cases of EBV-positive DLBCL, NOS. In this review, we summarize the current knowledge on DLBCL primarily occurring in the urinary bladder, with the aim of increasing clinician and pathologist awareness on this aggressive lymphoma rarely arising in the urinary bladder. Additionally, we focus on those entities which should be taken into consideration in the differential diagnosis, highlighting potential diagnostic pitfalls.

Case Report: Pituitary metastasis as a presenting manifestation of silent gastric cardia adenocarcinoma.

Introduction: Pituitary metastases are very rare in cancer patients and often originate from lung or breast tumors. They usually occur in patients with known metastatic disease, but rarely may be the first presentation of the primary tumor. Methods: We present the case of a 58 years-old-man who reported a three-month history of polyuria-polydipsia syndrome, generalized asthenia, panhypopituitarism and bitemporal hemianopsia. Brain-MRI showed a voluminous pituitary mass causing posterior sellar enlargement and compression of the surrounding structures including pituitary stalk, optic chiasm, and optic nerves. Results: The patient underwent neurosurgical removal of the mass. Histological examination revealed a poorly differentiated adenocarcinoma of uncertain origin. A total body CT scan showed a mass in the left kidney that was subsequently removed. Histological features were consistent with a clear cell carcinoma. However, endoscopic examination of the digestive tract revealed an ulcerating and infiltrating adenocarcinoma of the gastric cardia. Total body PET/CT scan with 18F-FDG confirmed an isolated area of accumulation in the gastric cardia, with no hyperaccumulation at other sites. Conclusion: To the best of our knowledge, there are no reports of pituitary metastases from gastric cardia adenocarcinoma. Our patient presented with symptoms of sellar involvement and without evidence of other body metastases. Therefore, sudden onset of diabetes insipidus and visual deterioration should lead to the suspicion of a rapidly growing pituitary mass, which may be the presenting manifestation of a primary extracranial adenocarcinoma. Histological investigation of the pituitary mass can guide the diagnostic workup, which must however be complete.

Feasibility and efficiency of European guidelines for NAFLD assessment in patients with type 2 diabetes: A prospective study.

AIM: We aimed to evaluate the feasibility and efficiency of a guidelines-compliant NAFLD assessment algorithm in patients with newly diagnosed type 2 diabetes (T2D). METHODS: Consecutive patients aged < 75 newly diagnosed with T2D without coexisting liver disease or excessive alcohol consumption were enrolled. Patients were stratified based on liver enzymes, fatty liver index, ultrasound, fibrosis scores and liver stiffness measurement. Referral rates and positive predictive values (PPVs) for histological non-alcoholic steatohepatitis (NASH) and significant fibrosis were evaluated. RESULTS: Of the 171 enrolled patients (age 59 ± 10.2 years, 42.1% females), 115 (67.3%) were referred to a hepatologist due to abnormal liver enzymes (n = 60) or steatosis plus indeterminate (n = 37) or high NAFLD fibrosis score (n = 18). Liver biopsy was proposed to 30 patients (17.5%), but only 14 accepted, resulting in 12 NASH, one with significant fibrosis. The PPV of hepatological referral was 12/76 (15.8%) for NASH and 1/76 (1.3%) for NASH with significant fibrosis. The PPV of liver biopsy referral was 12/14 (85.7%) for NASH and 1/14 (7.1%) for NASH with significant fibrosis. CONCLUSIONS: By applying a guidelines-compliant algorithm, many patients with T2D were referred for hepatological assessment and liver biopsy. Further studies are necessary to refine non-invasive algorithms.

Gastrointestinal Manifestations in Systemic Mastocytosis: The Need of a Multidisciplinary Approach.

Mastocytosis represents a heterogeneous group of neoplastic mast cell disorders. The basic classification into a skin-limited disease and a systemic form with multi-organ involvement remains valid. Systemic mastocytosis is a disease often hard to diagnose, characterized by different symptoms originating from either the release of mast cell mediators or organ damage due to mast cell infiltration. Gastrointestinal symptoms represent one of the major causes of morbidity, being present in 60-80% of patients. A high index of suspicion by clinicians and pathologists is required to reach the diagnosis. Gastrointestinal mastocytosis can be a challenging diagnosis, as symptoms simulate other more common gastrointestinal diseases. The endoscopic appearance is generally unremarkable or nonspecific and gastrointestinal mast cell infiltration can be focal and subtle, requiring an adequate sampling with multiple biopsies by the endoscopists. Special stains, such as CD117, tryptase, and CD25, should be performed in order not to miss the gastrointestinal mast cell infiltrate. A proper patient's workup requires a multidisciplinary approach including gastroenterologists, endoscopists, hematologists, oncologists, and pathologists. The aim of this review is to analyze the clinicopathological features of gastrointestinal involvement in systemic mastocytosis, focusing on the relevance of a multidisciplinary approach.

Next-Generation Sequencing Panel for 1p/19q Codeletion and IDH1-IDH2 Mutational Analysis Uncovers Mistaken Overdiagnoses of 1p/19q Codeletion by FISH.

The 1p/19q codeletion is the result of a translocation between chromosome 1 (Chr1p) and chromosome 19 (Chr19q) with the loss of derivative (1;19)(p10;q10) chromosome. The 1p/19q codeletion has predictive and prognostic significance, and it is essential for the classification of gliomas. In routine practice, the fluorescence in situ hybridization (FISH) diagnosis of 1p/19q codeletion is sometimes unexpected. This study aimed to develop a next-generation sequencing panel for the concurrent definition of the 1p/19q codeletion and IDH1/IDH2 mutation status to resolve these equivocal cases. A total of 65 glioma samples were investigated using a 1p/19q-single-nucleotide polymorphism (SNP)-IDH panel. The panel consists of 192 amplicons, including SNPs mapping to Chr1 and Chr19 and amplicons for IDH1/IDH2 analysis. The 1p/19q SNP-IDH panel consistently identified IDH1/IDH2 mutations. In 49 of 60 cases (81.7%), it provided the same 1p/19q results obtained by FISH. In the remaining 11 cases, the 1p/19q SNP-IDH panel uncovered partial chromosome imbalances as a result of interstitial amplification or deletion of the regions where the FISH probes map, leading to a mistaken overdiagnosis of 1p/19q codeletion by FISH. The 1p/19q SNP-IDH next-generation sequencing panel allows reliable analysis of the 1p/19q codeletion and IDH1/IDH2 mutation at the same time. The panel not only allows resolution of difficult cases but also represents a cost-effective alternative to standard molecular diagnostics procedures.

Primary classic Hodgkin lymphoma of the ileum and Epstein-Barr virus mucocutaneous ulcer of the colon: two entities compared.

Primary classic Hodgkin lymphoma of the gastrointestinal tract represents a rare occurrence. A full patient's work-up is essential in order to exclude a secondary intestinal involvement. Histologically Epstein-Barr virus mucocutaneous ulcer closely resembles Hodgkin lymphoma. The differential diagnosis between these two entities is relevant, since both the therapeutic approach and the clinical behavior are different. Herein, we describe a case of primary classic Hodgkin lymphoma arising in the ileum and a case of Epstein-Barr virus mucocutaneous ulcer of the colon, focusing on the main clinicopathological differences.

Three different synchronous primary lung tumours: a case report with extensive genetic analysis and review of the literature.

Synchronous triple lung tumours are rare and little is known as for their genetic basis. Here we report a case of a 59 years old male with three synchronous independent and histological different primary tumours of the left lung. Two nodules were located in the upper lobe and consisted of an adenocarcinoma (ADC) and an endobronchial poorly differentiated squamous cell carcinoma (SCC). A third nodule of the lower lobe corresponded to a small cell neuroendocrine carcinoma (SCLC). To assess if they represented independent primary tumours and have common genetic profiles, tumours were investigated for loss of heterozygosity (LOH) at 40 chromosomal markers. A comparable fractional allelic loss of 0.52 was observed in the ADC and SCLC, while it was 0.28 in the SCC. Microallelotyping analysis did not reveal a common genetic profile, supporting the hypothesis that the three synchronous tumours are truly independent primaries with different histogenesis.

Genetics of a combined lung small cell carcinoma and large cell neuroendocrine carcinoma with adenocarcinoma.

Combined nonneuroendocrine-neuroendocrine lung tumors are relatively infrequent and little is known as for their genetic basis. Here, we report the case of a 69-year-old male with a solitary neoplasm in the upper lobe of the right lung. At histological examination, the tumor showed two components. The main part was an adenocarcinoma of the acinar type. The second part showed morphological and immunohistochemical phenotype of a neuroendocrine carcinoma composed of a small cell lung carcinoma and a large cell neuroendocrine carcinoma. The aim of our study was to investigate the genetic relationship between neuroendocrine and nonneuroendocrine tumor components. To this purpose, we performed a loss of heterozygosity (LOH) analysis with 40 chromosomal microsatellite markers. Microallelotyping revealed a common genetic profile in the different tumor areas. In 9 of 30 informative regions analyzed, LOH involved the same allele in all components, regardless of their histological type and grade. These findings support the true combined nature of this exocrine-neuroendocrine carcinoma of the lung and suggest a common monoclonal origin from a pluripotent epithelial (alveolar or bronchial) precursor cell for the two different tumor components.

A case of colloid milium in patient with beta thalassaemia major.

Colloid milium (CM) is a rare cutaneous condition characterized by translucent papules occurring on sun-exposed regions including the face, neck and dorsal aspects of the hands and back. Clinically, there are two variants of CM: an adult-onset type and a juvenile form. The juvenile form is inherited and presents before puberty. Probably this variant is because of an inherited susceptibility to ultraviolet (UV) light and can be transmitted as both autosomal recessive and autosomal dominant character. In this paper, we report an interesting case of adult CM in a transfused patient affected by beta thalassaemia major. The association of CM with beta thalassaemia, to our knowledge, has not been reported previously, in literature. Thus, this case represents the first case of CM associated with beta thalassaemia major. In our view, the lesion could be related to excess iron, similar to pseudoxanthoma elastic-like lesions, another cutaneous disorder which is present in beta thalassaemia. As our patient is a farmer and was exposed to sun during his work, UV light damage could have have a role in promoting the development of the disease. Other cases of CM associated with beta thalassaemia should be reported to confirm these hypotheses.

Human papilloma virus (HPV) status, p16INK4a, and p53 overexpression in epithelial malignant and borderline ovarian neoplasms.

This investigation is the first to evaluate simultaneously human papilloma virus (HPV) status, p16(INK4a), and p53 immunoreactivity in epithelial ovarian neoplasms. The results were analyzed and correlated with histological type, histological grade, and survival of patients. Subtypes considered are papillary serous and mucinous. Polymerase chain reaction (PCR) analysis, performed in our previous study, had already demonstrated a small number of HPV-positive epithelial ovarian neoplasms. No significant correlation was found between the presence of HPV DNA and subtypes of ovarian neoplasms; thus, HPV cannot be considered responsible for epithelial ovarian neoplasm. Since p16 immunoreactivity was present in many other HPV-negative cases of epithelial ovarian neoplasms, this study suggests that p16 overexpression in some neoplasms of the female genital tract is not related to HPV carcinogenesis. A higher p53 expression rate observed between borderline and malignant serous tumors and between serous and mucinous neoplasms can confirm a recent dualistic model of ovarian carcinogenesis. According to this theory, low-grade serous carcinomas (serous intraepithelial carcinomas, serous borderline neoplasm, and ovarian mucinous neoplasms) (type I tumors) develop from mutations of KAS and BRAF, while high-grade serous carcinomas (type II tumors) develop from mutation of p53. In malignant neoplasms, for univariate analysis, patient survival seems to be related to p53, strong and diffuse p16 overexpression, and the stage of development of neoplasms at the diagnosis. In multinomial logistic regression, used to evaluate the role of staging, grading, p16 and p53 immunopositivity as predictor variables of unfavorable outcome of the disease, only p16 positivity was significantly related to the poor prognosis of the cancer.