COVID-19-Associated Nonocclusive Fibrin Microthrombi in the Heart.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant clinical presentation, coronavirus disease 2019 (COVID-19), is an emergent cause of mortality worldwide. Cardiac complications secondary to this infection are common; however, the underlying mechanisms of such remain unclear. A detailed cardiac evaluation of a series of individuals with COVID-19 undergoing postmortem evaluation is provided, with 4 aims: (1) describe the pathological spectrum of the myocardium; (2) compare with an alternate viral illness; (3) investigate angiotensin-converting enzyme 2 expression; and (4) provide the first description of the cardiac findings in patients with cleared infection. METHODS: Study cases were identified from institutional files and included COVID-19 (n=15: 12 active, 3 cleared), influenza A/B (n=6), and nonvirally mediated deaths (n=6). Salient information was abstracted from the medical record. Light microscopic findings were recorded. An angiotensin-converting enzyme 2 immunohistochemical H-score was compared across cases. Viral detection encompassed SARS-CoV-2 immunohistochemistry, ultrastructural examination, and droplet digital polymerase chain reaction. RESULTS: Male sex was more common in the COVID-19 group (P=0.05). Nonocclusive fibrin microthrombi (without ischemic injury) were identified in 16 cases (12 COVID-19, 2 influenza, and 2 controls) and were more common in the active COVID-19 cohort (P=0.006). Four active COVID-19 cases showed focal myocarditis, whereas 1 case of cleared COVID-19 showed extensive disease. Arteriolar angiotensin-converting enzyme 2 endothelial expression was lower in COVID-19 cases than in controls (P=0.004). Angiotensin-converting enzyme 2 myocardial expression did not differ by disease category, sex, age, or number of patient comorbidities (P=0.69, P=1.00, P=0.46, P=0.65, respectively). SARS-CoV-2 immunohistochemistry showed nonspecific staining, whereas ultrastructural examination and droplet digital polymerase chain reaction were negative for viral presence. Four patients (26.7%) with COVID-19 had underlying cardiac amyloidosis. Cases with cleared infection had variable presentations. CONCLUSIONS: This detailed histopathologic, immunohistochemical, ultrastructural, and molecular cardiac series showed no definitive evidence of direct myocardial infection. COVID-19 cases frequently have cardiac fibrin microthrombi, without universal acute ischemic injury. Moreover, myocarditis is present in 33.3% of patients with active and cleared COVID-19 but is usually limited in extent. Histological features of resolved infection are variable. Cardiac amyloidosis may be an additional risk factor for severe disease.

Cyto-histologic correlation of crystal-storing histiocytosis: Rare presentation in breast, predating diagnosis of B-cell lymphoma by two years.

Crystal-storing histiocytosis (CSH) is a rare disorder characterized by the accumulation of crystalized immunoglobulins within the cytoplasm of histiocytes. It is often associated with an underlying lymphoproliferative or plasma cell disorder. Most patients with CSH are asymptomatic in regard to the disease and are incidentally discovered. Herein we present cyto-histologic correlation of a rare example of CSH presenting with a two-year interval between original diagnosis of CSH and confirmation of a low-grade B-cell lymphoma.

Disseminated blastomycosis in a kidney transplant recipient.

Disseminated blastomycosis in solid organ transplant is uncommon. The diagnosis is usually challenging due to vague clinical presentations, which could lead to a devastating outcome. We reported a unique case of disseminated blastomycosis with laryngeal involvement in a kidney transplant recipient who presented with hoarseness. The diagnosis was made by histopathology and culture of laryngeal mass.

Neuropathology of COVID-19: a spectrum of vascular and acute disseminated encephalomyelitis (ADEM)-like pathology.

We report the neuropathological findings of a patient who died from complications of COVID-19. The decedent was initially hospitalized for surgical management of underlying coronary artery disease. He developed post-operative complications and was evaluated with chest imaging studies. The chest computed tomography (CT) imaging results were indicative of COVID-19 and he was subsequently tested for SARS-CoV-2, which was positive. His condition worsened and he died after more than 2 weeks of hospitalization and aggressive treatment. The autopsy revealed a range of neuropathological lesions, with features resembling both vascular and demyelinating etiologies. Hemorrhagic white matter lesions were present throughout the cerebral hemispheres with surrounding axonal injury and macrophages. The subcortical white matter had scattered clusters of macrophages, a range of associated axonal injury, and a perivascular acute disseminated encephalomyelitis (ADEM)-like appearance. Additional white matter lesions included focal microscopic areas of necrosis with central loss of white matter and marked axonal injury. Rare neocortical organizing microscopic infarcts were also identified. Imaging and clinical reports have demonstrated central nervous system complications in patients' with COVID-19, but there is a gap in our understanding of the neuropathology. The lesions described in this case provide insight into the potential parainfectious processes affecting COVID-19 patients, which may direct clinical management and ongoing research into the disease. The clinical course of the patient also illustrates that during prolonged hospitalizations neurological complications of COVID may develop, which are particularly difficult to evaluate and appreciate in the critically ill.

Persistent aortic inflammation in patients with giant cell arteritis.

OBJECTIVES: To investigate the clinicopathologic features of patients with giant cell arteritis (GCA) who had thoracic aorta aneurysm or dissection surgery. METHODS: Patients who had thoracic aorta surgery between January 1, 2000, and December 31, 2021, at the Mayo Clinic, Rochester, Minnesota, were identified with current procedural terminology (CPT) codes. The identified patients were screened for a prior diagnosis of GCA with diagnostic codes and electronic text search. The available medical records of all the patients of interest were manually reviewed. Thoracic aorta tissues obtained during surgery were re-evaluated in detail by pathologists. The clinicopathologic features of these patients were analyzed. Overall observed survival was compared with lifetable rates from the United States population. RESULTS: Of the 4621 patients with a CPT code for thoracic aorta surgery, 49 had a previous diagnosis of GCA. Histopathologic evaluation of the aortic tissue revealed active aortitis in most patients with GCA (40/49, 82%) after a median (IQR) of 6.0 (2.6-10.3) years from GCA diagnosis. All patients were considered in clinical remission at the time of aortic surgery. The overall mortality compared to age and sex-matched general population was significantly increased with a standardized mortality ratio of 1.55 (95% CI, 1.05-2.19). CONCLUSION: Histopathologic evaluation of the thoracic aorta obtained during surgery revealed active aortitis in most patients with GCA despite being considered in clinical remission several years after GCA diagnosis. Chronic, smoldering aortic inflammation likely contributes to the development of aortic aneurysm and dissection in GCA.

Sarcina ventriculi in an Endoscopic Ultrasound-Guided Fine Needle Aspiration of a Perigastric Lymph Node with Metastatic Pancreatic Adenocarcinoma: A Carry-Through Contaminant Bacterial Microorganism from the Stomach.

Sarcina ventriculi is a rare gram-positive coccus increasingly reported in patients with a history of delayed gastric emptying or gastric outlet obstruction and is sometimes seen in association with emphysematous gastritis and perforation. We report a case of a 67-year-old male who presented with epigastric pain. CT imaging and cholangiopancreatography were concerning for pancreatic neoplasia. Upper endoscopic ultrasound-guided fine needle aspiration cytology of a perigastric lymph node confirmed metastatic adenocarcinoma of pancreatic origin, and cocci arranged in a tetrad fashions characteristic of Sarcina ventriculi were noted. To our knowledge, this is the first reported case of Sarcina ventriculi in an FNA of metastatic pancreatic carcinoma in a perigastric lymph node. These organisms likely represent carry-through contaminants from the transgastric approach of the endoscopic FNA.

Cryptococcal Meningitis Presenting as New-Onset Seizures in an Immunocompetent Patient.

This report describes a 30-year-old immunocompetent male with new-onset seizures, later found on imaging to have 2 enhancing lesions in the brain. The patient underwent a left parietal craniectomy with resection of one of the masses, which demonstrated focal areas of necrosis and many small cystic structures positive for periodic acid-Schiff and Gomori's methenamine silver special stain. Numerous laboratory examinations, including HIV test, rapid plasma reagin, toxoplasma immunoglobulin G and immunoglobulin M, Lyme, cytomegalovirus, tuberculosis, cysticercosis, and Echinococcus serology, were all negative. Despite negative cerebrospinal fluid (CSF) culture and several negative CSF antigen tests, continued investigation, and follow-up, CSF antigen testing ultimately revealed Cryptococcus as the causative agent. In light of the mysterious and unusual presentation, the authors discuss potential infectious differential diagnoses in patients with atypical clinical presentation, laboratory tests, and surgical pathology.

Malignant Mesothelioma of the Tunica Vaginalis Testis-A Malignancy Associated With Asbestos Exposure and Trauma: A Case Report and Literature Review.

In this article, we report an unusual case of a malignant mesothelioma of the testis, presenting as hydrocele. The patient has a known medical history of trauma and occupational exposure to asbestos. The clinical features of this injury are discussed together with its immunohistochemistry. Surgical intervention is discussed due to the nature of this pathology.