SARS-CoV-2 detection in primary thyroid sarcoma: coincidence or interaction?

Introduction Thyroid dysfunctions associated with SARS-CoV-2 are emerging in scientific literature. During the second COVID-19 epidemic spread, we evaluated a patient with the suspect of subacute thyroiditis. Methods and results Specimen from fine-needle aspiration of a hypoechoic undefined area was analyzed for cytology and for SARS-CoV-2 detection. SARS-CoV-2 was retrieved by real-time polymerase chain reaction on the cytologic sample, which was then cultured on Vero E6 cells and demonstrated to be cytopathic. Whole-genome sequence was deposited. Histological exam diagnosed a rare case of primary thyroid sarcoma with diffuse and strong expression of mouse double minute 2 homolog (MDM2) oncoprotein. Ultrastructural examination confirmed, in several neoplastic cells, the presence of viral particles in cytoplasmic vacuoles. Conclusions In our hypothesis, SARS-CoV-2 and sarcoma coexistence could represent a synergistic interplay, ultimately favoring both viral persistence and tumor proliferation: the overexpression of MDM2 in tumor cells might have generated a favorable immunological niche for SARS-CoV-2 localization and, in turn, SARS-CoV-2 could have favored tumor growth by inducing MDM2-mediated p53 downregulation. Functional studies are needed to confirm this suggestive pathway.

Sickle Cell Disease with Dermatomyositis - a Rare and Complex Comorbidity

Introduction and Case Presentation - A 4 yrs old female with sickle cell disease (SCD) and intermittent asthma presented with polyarthralgia predominantly involving bilateral hip and knee joints and became non-ambulatory over a course of 2 months. She developed chronic facial swelling, and a pruritic erythematous rash involving face, extensor surface of the hand and the right knee with significant weight loss. Physical examination was significant for heliotropic rash on the eyelids, Also present were Gottron's papules and macules on both hands and right knee along with right leg tenderness, muscle weakness, wasting and decreased range of motion at bilateral hip joints along with inguinal lymphadenopathy. Investigations were significant for severe anemia with hyperactive bone marrow, metabolic acidosis, normonatremic dehydration with absence of any evidence of an ongoing infectious process. Her Anti Nucleic acid antibody (ANA) panel, Aldolase, Rheumatoid factor and Angiotensin-1-Converting Enzyme levels were unremarkable. Creatine kinase levels were near normal. Her Neopterin and LDH levels were significantly elevated. Imaging with MRI scan with multiplanar multisequence of bilateral lower extremities and Pelvis showed significant diffuse myositis and soft tissue swelling. The diagnostic criterion for Juvenile Dermatomyositis include: (1) the typical pathognomonic rashes, (2) elevated muscle enzymes, (3) symmetric proximal muscle weakness and neck flexors, (4) muscle biopsy characteristic of juvenile dermatomyositis, and (5) EMG findings characteristic of juvenile dermatomyositis. Having ruled out an infectious process a muscle biopsy was performed, which also was subjected to Electron Microscopic (EM) analysis as the patient did not have extremely high muscle enzymes, necessitating a muscle biopsy . Hematoxylin & eosin stained sections were compatible with inflammatory myopathy. Ultrastructural examination demonstrated myofiber size variability, frequent rounded atrophic fibers with myofibrillar disarray, internalized nuclei, and increased interstitial collagen deposition. Endomysial capillaries were decreased in number, but showed reactive endothelial changes. Some showed prominent endothelial tubuloreticular inclusions (Figure),characteristic of JD. In summary, absence of serologic and tissue evidence of any other inflammatory myopathy, offending pharmacotherapy, infectious disease and presence of imaging and tissue evidence (vascular injury and tubuloreticular inclusions) comprised the work up of a child with SCD with Dermatomyositis. Management- Prompt treatment with prednisone (2 mg/kg/day), methotrexate (10 mg) weekly and monthly IVIG (2gm/kg/dose) infusions was started, once diagnosis was confirmed showing a dramatic clinical response. Prednisone was slowly tapered after 1 month of treatment. She showed gradual improvement in her symptoms, the strength in proximal muscle in both upper and lower limbs improved eventually to a point where the contractures in the elbows and knees improved and she started ambulating without support. Patient's Hydroxyurea was restarted at a low dose of 15mg/kg/day and increased to 20 mg/kg/day slowly, as her systemic symptoms of Dermatomyositis subsided. Discussion- Working up a child with SCD who presents with sudden onset non weight bearing can be complicated. Vaso-occlusive bony pain crisis , Osteomyelitis , septic arthritis are common clinical scenarios, but an underlying rheumatologic illness in pediatric SCD patient mimicking a sickle cell pain crisis presents a unique diagnostic challenge one which, albeit has been reported in literature, but rarely includes electron microscopic ultrastructural examination as part of evidence and work up. This patient's relatively mild muscle enzyme elevation and Hydroxyurea therapy made the initial diagnosis more challenging. We present the first pediatric SCD patient with clinically and pathologically proven case of Dermatomyositis with EM evidence, highlighting a unique clinical scenario ,diagnostic challenges and management strategies. Figure 1 Figure 1. Disclosures Jain: Octapharma: Consultancy; CSL Behring: Consultancy, Speakers Bureau; GBT: Consultancy; Blue Bird Bio: Consultancy; Takeda: Consultancy, Speakers Bureau.

Transcriptomics and Transmission Ultrastructural Examination Reveals the Nephrotoxicity of Cadmium in Laying Hens

The objective of this study was to reveal the effects of cadmium (Cd) on ultrastructural changes, oxidative stress, and transcriptome expression in the kidneys of laying hens. Seventy-two healthy Hy-Line brown laying hens at 41 weeks old were randomly allocated to four treatment groups with six replicates. The control group received a basal diet without additional Cd incorporation, and the other three treatment groups received diets supplemented with 15, 30, or 60 mg Cd /kg of feed. After 6 weeks of exposure the results show that administration of 60 mg/kg Cd significantly reduced (P < 0.05) eggshell thickness. With an increase in the Cd concentration in feed, the concentrations of renal Zn, Fe also had changed. Renal histopathology and ultrastructure also showed aggravated damage to glomeruli and renal tubules, and the deformation of nuclei and mitochondria in all Cd treatment groups. With an increase in Cd in feed, the activity of GPX and CAT was significantly reduced (P＜0.05), while the activity of T-AOC was decreased (P＜0.05) only in the 60 mg/kg Cd group. RNA-seq analysis revealed that 410 genes displayed differential expression (≥ 1.5-fold) in the 60 mg/kg supplementation group, compared to the control group. GO and KEGG pathway analysis results showed that Cd affected many genes involved in mitochondria and ion transport. In conclusion, this study elaborates the mechanisms underlying renal toxicity caused by Cd, which might provide target candidate genes for alleviating Cd poisoning in laying hens.

CLN8 Mutations Presenting with a Phenotypic Continuum of Neuronal Ceroid Lipofuscinosis—Literature Review and Case Report

CLN8 is a ubiquitously expressed membrane-spanning protein that localizes primarily in the ER, with partial localization in the ER-Golgi intermediate compartment. Mutations in CLN8 cause late-infantile neuronal ceroid lipofuscinosis (LINCL). We describe a female pediatric patient with LINCL. She exhibited a typical phenotype associated with LINCL, except she did not present spontaneous myoclonus, her symptoms occurrence was slower and developed focal sensory visual seizures. In addition, whole-exome sequencing identified a novel homozygous variant in CLN8, c.531G>T, resulting in p.Trp177Cys. Ultrastructural examination featured abundant lipofuscin deposits within mucosal cells, macrophages, and monocytes. We report a novel CLN8 mutation as a cause for NCL8 in a girl with developmental delay and epilepsy, cerebellar syndrome, visual loss, and progressive cognitive and motor regression. This case, together with an analysis of the available literature, emphasizes the existence of a continuous spectrum of CLN8-associated phenotypes rather than a sharp distinction between them.

Loss of Motor Protein MYO1C Causes Rhodopsin Mislocalization and Results in Impaired Visual Function

Unconventional myosins, linked to deafness, are also proposed to play a role in retinal cell physiology. However, their direct role in photoreceptor function remains unclear. We demonstrate that systemic loss of the unconventional myosin MYO1C in mice, specifically causes rhodopsin mislocalization, leading to impaired visual function. Electroretinogram analysis of Myo1c knockout (Myo1c-KO) mice showed a progressive loss of photoreceptor function. Immunohistochemistry and binding assays demonstrated MYO1C localization to photoreceptor inner and outer segments (OS) and identified a direct interaction of rhodopsin with MYO1C. In Myo1c-KO retinas, rhodopsin mislocalized to rod inner segments (IS) and cell bodies, while cone opsins in OS showed punctate staining. In aged mice, the histological and ultrastructural examination of the phenotype of Myo1c-KO retinas showed progressively shorter photoreceptor OS. These results demonstrate that MYO1C is important for rhodopsin localization to the photoreceptor OS, and for normal visual function.

Diagnostic Challenges in Epithelioid Pleural Mesothelioma: Case Series with Support from Electron Microscopy

The histological diagnosis of pleural epithelioid mesothelioma can be difficult in the case of rare variants or in the definition of neoplasm origin in patients with previous or concomitant tumours. Currently, several immunohistochemical reactions are available in the surgical pathologist’s armamentarium that allow us to obtain a more sensitive and specific diagnosis of malignant pleural mesothelioma. However, in some cases, the final interpretation remains inconclusive. Historically, ultrastructural examination has represented a useful tool for the definition of the mesothelial nature of neoplastic cells due to their peculiar morphological characteristics. The recent international guidelines for pathological diagnosis of pleural mesothelioma suggest the use of electron microscopy when the immunohistochemical reactions are equivocal or when further support of a diagnosis of mesothelioma is needed. This paper presents three cases of pleural epithelioid mesothelioma whose diagnoses were finally supported by ultrastructural examination.

Therapeutic Penetrating Keratoplasty using Full-Thickness Gamma Irradiated Corneal Tissue

Purpose: This paper is intended to report the ultrastructural and biological features of VisionGraft®, a commercially available acellular gamma-irradiated sterile cornea. This is the first known ultrastructural examination of the VisionGraft® with electron microscopy after in-vivo explanation. Observations: This graft was initially placed for tectonic purposes in a non-responsive culture positive Aspergillus keratitis in a 50 year-old diabetic male, unresponsive to maximal medical therapy. Five months later, a second penetrating keratoplasty with fresh tissue was performed and the Visiongraft® was submitted for histopathologic evaluation. This study reports that there is minimal regrowth of nerves and endothelial cells into the graft, and corneal clarity appears to be preserved even in the absence of endothelium. Conclusions and Importance: Examination of the acellular cornea showed no significant epithelial regrowth, no nerve regeneration, no infiltration by leukocytes or antigen presenting cells, no significant endothelial regrowth, and yet, surprisingly, no interstitial edema. We offer some hypotheses for these observations based on the histopathologic evaluation and offer some suggestions for future avenues of research.

Transplant Glomerulopathy: Importance of Ultrastructural Examination

<b><i>Background:</i></b> Transplant glomerulopathy (TG) is a morphologic alteration in glomeruli of renal allografts, characterized by glomerular basement membrane reduplications. <b><i>Summary:</i></b> TG is associated with progressive chronic allograft dysfunction and proteinuria and is a diagnostic feature of chronic antibody-mediated rejection (ABMR) in patients positive for donor-specific antibodies, according to the Banff schema for renal allograft pathology. It is a definitive endpoint in clinical trials and interventional studies for ABMR, but the lesion can also occur in the absence of definitive alloimmune injury, as a consequence of chronic thrombotic microangiopathy, and in some cases in association with hepatitis C infection. This review discusses the pathophysiology and clinical presentation of TG, the diagnostic features by light microscopy, and focuses on the sequential ultrastructural stages of the lesion. The differential diagnosis of TG, and Banff grading of the lesion, are reviewed. Clinicopathological indications for performing routine ultrastructural examination of renal allograft biopsies are discussed. <b><i>Key Messages:</i></b> TG can be diagnosed at an early stage by electron microscopy, before histological features are apparent, emphasizing the importance of ultrastructural examination of renal allograft biopsies for an early diagnosis, when therapeutic intervention may be beneficial.

Polypide anatomy of hornerid bryozoans (Stenolaemata: Cyclostomatida)

Bryozoans are small colonial coelomates whose colonies are made of individual modules (zooids). Like most coelomate animals, bryozoans have a characteristic body wall composition, including epidermis, extracellular matrix (ECM) and coelothelium, all pressed together. The order Cyclostomatida, however, presents the most striking deviation, in which the ECM and the corresponding coelothelium underlying major parts of the skeletal wall epidermis are “;peeled off” to form an independent membranous sac. The polypide anatomy and ultrastructure of this group is best known from one family, the Crisiidae (Articulata). Here we examined four species from the phylogenetically and ecologically contrasting family Horneridae (Cancellata) from New Zealand. Here we provide the first detailed ultrastructural examination of the hornerid polypide, including tentacles, mouth region, digestive system and the funiculus. We were able to trace continuity and transitions of cell and ECM layers throughout the whole polypide. In addition we identified that the funiculus is a lumen-free ECM cord with two associated muscles, disconnected from interzooidal pores. While agreeing with the general cyclostomate body plan, hornerids have some unique traits that make them worthy of additional study.HighlightsHornerids share a general cyclostomate body plan. The frontal tentacle ECM transitions into oral sphincter ECM, the abfrontal lophophore ECM becomes a septum between coelomic compartments, and the funuculus is a solid ECM cord supplied with muscles.

Morphology of the Novel Basimandibular Gland in the Ant Genus Strumigenys (Hymenoptera, Formicidae)

In 1999, Barry Bolton postulated the presence of a basimandibular gland in the mandibles in all species of the ant genus Strumigenys, solely based on scanning microscopy observations. We now confirm the presence of this putative gland in the proximal outer part of the mandibles of 22 investigated species by histological and ultrastructural examination, including 10 short- and 12 long-mandibulate species. All species have a basimandibular gland, that is formed by 15–25 µm thick epithelial cells and belongs to class-1 following the standard classification of insect exocrine glands. We consider it a novel gland because of its peculiar bowl-shape and special arrangement of the microvilli that are confined to large vacuolar spaces instead of reaching the cuticle. The gland is most pronounced in S. mutica, particularly in the queen. In addition to this gland, we also found scattered class-3 intramandibular gland cells in the mandibles. Queens of S. mutica are peculiar in having a cluster of these cells in the distal tip of their mandibles. As this species is a social parasite, further research is required to determine whether the development of these mandibular glands is related to its parasitic lifestyle.