Caseous Calcification of the Mitral Annulus: Calcified Toothpaste of the Heart.

ABSTRACT: Caseous calcification of the mitral annulus (CCMA) is a rare variant of mitral annular calcification (MAC) usually described as an antemortem finding. We report a case of sudden cardiac arrest in a 39-year-old male with end-stage renal disease undergoing hemodialysis with a history of Fabry disease by kidney biopsy. Autopsy revealed significant circumferential annular calcification in both mitral and aortic valves with a caseous gross appearance. Histologically, these areas consisted of amorphous basophilic material accompanied by a surrounding granulomatous-appearing infiltrate. Von Kossa staining on non-decalcified tissue revealed strong positive staining, confirming CCMA diagnosis. While identifiable, the atrioventricular node was displaced and distorted by caseous deposits. Toluidine blue staining of myocardium showed osmophilic accumulations, and electron microscopy (EM) showed myeloid/zebra bodies, consistent with Fabry disease. We posit that Fabry disease leads to end-stage kidney disease, altering calcium phosphate metabolism, a proposed mechanism for CCMA. This case highlights the multifactorial nature of sudden cardiac death in decedents with various structural cardiac changes and potential renal-disease-induced electrolyte imbalances. We aim to bring awareness to this rare entity, its potential role in a sudden cardiac death, and to highlight the need to use non-decalcified tissue when staining for calcium to establish the diagnosis.

Carotid Intimal Sarcoma Presenting as Large Vessel Occlusion and Diagnosed by Embolus Histopathology: Case Report.

Objective: The objective of this study was to present the clinical, histopathologic, and radiographic findings of a unique case of intimal sarcoma (IS) embolus presenting as a large vessel occlusion causing an ischemic stroke without a detectable primary tumor site. Methods: Extensive examinations, multimodal imaging, laboratory testing, and histopathologic analysis were used in evaluation. Results: We report the case of a patient who presented with acute embolic ischemic stroke and was found to have IS based on a histopathologic evaluation of his embolectomy specimen. Subsequent comprehensive imaging studies failed to detect a primary tumor site. Multidisciplinary interventions including a course of radiotherapy were performed. The patient died of recurrent multifocal strokes 92 days after diagnosis. Discussion: Meticulous histopathologic analysis should be conducted on cerebral embolectomy specimens. Histopathology may be useful in diagnosing IS.

Objective Visual Analog Scale for Biopsy Diagnosis of Helicobacter pylori Infection in Clinical Practice.

Historic and current pathology society guidelines recommend using visual gestalt to identify substantial inflammatory cell infiltrate in Helicobacter pylori gastritis, but these scales were subjectively designed. This study aims to objectively investigate the density of inflammation that justifies additional workup for H. pylori infection. We retrospectively identified 2 patient cohorts who had undergone endoscopy with gastric biopsies; 1 with H. pylori infection (n=66), confirmed with a positive stool antigen test and/or Campylobacter-like organism test, and 1 without infection (n=81). Antral and body biopsies were selected from each case, if available, and stained with MUM-1 to highlight mucosal plasma cells. Digital analysis was performed to calculate the number of plasma cells/mm2, termed the "inflammatory score" (IS). Patients with H. pylori infection had an average of 1289 plasma cells/mm2 in the antrum and 835 plasma cells/mm2 in the body, compared with 346 plasma cells/mm2 in the antrum and 178 plasma cells/mm2 in the body in patients without infection. IS cut-off values for a positive infection were 714 plasma cells/mm2 in the antrum and 316 plasma cells/mm2 in the body, with high sensitivities and specificities in both the antrum (92%, 92%) and body (85%, 84%), respectively. A visual analog scale was created to provide a histologic correlate of the observed IS ranges and cut-offs. This practical and objective scale is associated with a high sensitivity and specificity for diagnosing H. pylori infection and justifies moving away from upfront universal H. pylori testing in routine clinical practice.

A Descriptive and Quantitative Immunohistochemical Study Demonstrating a Spectrum of Platelet Recruitment Patterns Across Pulmonary Infections Including COVID-19.

OBJECTIVES: Pulmonary platelet deposition and microangiopathy are increasingly recognized components of coronavirus disease 2019 (COVID-19) infection. Thrombosis is a known component of sepsis and disseminated intravascular coagulation. We sought to compare the level of platelet deposition in the pulmonary vasculature in cases of confirmed COVID-19 infection to other lung injuries and infections. METHODS: Immunohistochemistry was performed on 27 autopsy cases and 2 surgical pathology cases targeting CD61. Multiple cases of normal lung, diffuse alveolar damage, COVID-19, influenza, and bacterial and fungal infections, as well as one case of pulmonary emboli, were included. The levels of CD61 staining were compared quantitatively in the autopsy cases, and patterns of staining were described. RESULTS: Nearly all specimens exhibited an increase in CD61 staining relative to control lung tissue. The area of CD61 staining in COVID-19 infection was higher than influenza but still comparable to many other infectious diseases. Cases of aspiration pneumonia, Staphylococcus aureus infection, and blastomycosis exhibited the highest levels of CD61 staining. CONCLUSIONS: Platelet deposition is a phenomenon common to many pulmonary insults. A spectrum of staining patterns was observed, suggestive of pathogen-specific mechanisms of platelet deposition. Further study into the mechanisms driving platelet deposition in pulmonary injuries and infections is warranted.

Printculture of Surgical Pathology and Autopsy Specimens.

OBJECTIVES: Printculture is a method of microbiologic assessment previously described for use in the autopsy setting. We sought to compare printculture of surgical and autopsy pathology specimens to standard microbiology culture using matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF)-based colony identification. METHODS: Printculture was performed on 18 frozen samples with corresponding standard culture results. The results of MALDI-TOF identification of colonies recovered by printculture were compared with standard cultures, and percent concordance was calculated. RESULTS: There was 95.8% concordance to standard culture methods for cases with infections and 100% concordance for cases without infection. The pattern of growth was found to aid in the distinction between contamination and true infection. CONCLUSIONS: Printculture allows the identification of microorganisms from routinely frozen tissues and provides a bridge between microbiology and histomorphology through the identification of associated histologic features of infection. This technique can be successfully integrated into autopsy and surgical pathology workup of potentially infected tissues.

Aneurysmal Bone Cyst of the Maxillary Sinus with USP6 Rearrangement: Case Report of a Rare Entity and Review of the Literature.

Aneurysmal bone cysts (ABCs) are benign lesions which most frequently occur in the long bones of pediatric patients. Long thought to be reactive, recent molecular advances have demonstrated that the majority of primary ABCs harbor rearrangements of the USP6 gene, confirming their neoplastic nature. Secondary ABCs arising from other lesions do not demonstrate this recurrent genetic anomaly. ABCs rarely occur in the craniofacial bones, and sinonasal ABCs are exceedingly rare. We report a case of a primary ABC arising the maxillary sinus of a 14-year-old female, which was found to harbor USP6 rearrangement. We describe the clinical, radiologic, and pathologic features of this case, and review the current literature on craniofacial ABCs. Careful histologic evaluation and genetic studies are warranted in order to confirm the rare occurrence of a primary sinonasal ABC.

SHIV antigen immunization alters patterns of immune responses to SHIV/malaria coinfection and protects against life-threatening SHIV-related malaria.

Whether vaccination against a virus can protect against more virulent coinfection with the virus and additional pathogen(s) remains poorly characterized. Overlapping endemicity of human immunodeficiency virus (HIV) and malaria suggests that HIV/malaria coinfection frequently complicates acute and chronic HIV infection. Here we showed that vaccination of macaques with recombinant Listeria ΔactA prfA* expressing simian/human immunodeficiency virus (SHIV) gag and env elicited Gag- and Env-specific T-cell responses, and protected against life-threatening SHIV-related malaria after SHIV/Plasmodium fragile coinfection. SHIV antigen immunization reduced peak viremia, resisted SHIV/malaria-induced lymphoid destruction, and blunted coinfection-accelerated decline of CD4(+) T-cell counts after SHIV/malaria coinfection. SHIV antigen immunization also weakened coinfection-driven overreactive proinflammatory interferon-γ (IFNγ) responses and led to developing T helper cell 17/22 (Th17/Th22) responses after SHIV/malaria coinfection. The findings suggest that vaccination against AIDS virus can alter patterns of immune responses to the SHIV/malaria coinfection and protect against life-threatening SHIV-related malaria.