Veterinary Pathology最新文献

An 11-year-old, Damaraland mole-rat queen died after several months of abdominal distension with no other clinical signs, and a necropsy was performed. Grossly, numerous red-white, smooth masses, ranging from a few millimeters to 1 cm in diameter, were widely scattered across the surfaces of the diaphragm, mesentery, and peritoneum. The pulmonary hilar, mediastinal, mesenteric, and renal lymph nodes were enlarged. Histologically, the masses and the enlarged lymph nodes consisted of atypical cells with abundant eosinophilic cytoplasm and large, eccentrically positioned nuclei. Multinucleated giant cells were often intermixed with these cells. Based on the positive immunolabeling of macrophage markers IBA1 and CD163, the lack of detectable pathogens, and the prominent dissemination of these cells, these lesions were diagnosed as histiocytic sarcoma. This is the first case of histiocytic sarcoma and the first case of a spontaneous tumor in a Damaraland mole-rat, a burgeoning non-traditional animal model of longevity and purported cancer resistance.

Fourteen feline nodal lymphomas previously diagnosed as Hodgkin-like lymphoma (HLL) were studied through histologic, immunohistochemical, and molecular analyses to further characterize feline HLL. The cohort comprised 12 domestic shorthair and 2 Maine coon cats, with a male/female ratio of 1.3 and a median age of 9.5 years. Reed-Sternberg and Hodgkin cells were observed in 14/14 HLLs, while a minority of cells resembling lymphocyte-predominant cells were observed in 5/14 (36%) cases. Neoplastic cells were embedded in a mixed reactive background mainly composed of T and B lymphocytes and histiocytes. Necrosis was present in 9/14 (64%) cases. Various percentages of neoplastic cells were positive for CD30, PAX5, and MUM1 in 14/14 cases and for CD20 in 12/14 (86%) cases. Polymerase chain reaction (PCR) for antigen receptor rearrangements (PARR) by agarose gel electrophoresis identified clonal immunoglobulin heavy chain (IGH) in 9/14 (64%) cases, clonal T-cell receptor-gamma (TRG) rearrangements in 4/14 (29%) cases, and polyclonal IGH and TRG in 1 case. The predominance of Reed-Sternberg and Hodgkin cells and a CD30+/PAX5+/MUM1+ immunophenotype were consistent findings in this case series and align with the human classic form of Hodgkin lymphoma (HL). However, in contrast to the human tumor, most feline HLLs express CD20. Based on the human HL classification, feline HLLs were further categorized as lymphocyte-rich (6/14, 43%), mixed cellularity (4/14, 29%), nodular sclerosis (2/14, 14%), and lymphocyte-depleted (2/14, 14%). Feline HLL is a complex neoplasm that requires refinement of diagnostic criteria to improve classification and management.

Feline mammary carcinomas (FMCs) have a highly malignant and metastatic behavior and are associated with a poor prognosis. There is a need to identify new effective therapies for FMC. Signal transducer and activator of transcription 3 (STAT3) is activated in various human and animal tumors. It has been proposed as a potential prognostic marker and therapeutic target in human breast cancer (HBC). Given the similarities between HBC and FMCs, we hypothesized STAT3 expression in FMCs may be prognostically significant. In this study, 60 FMC samples were immunohistochemically evaluated for the expression of total STAT3 (tSTAT3), phosphorylated STAT3 (pSTAT3), and Ki-67. The pSTAT3 and Ki-67 indexes were calculated, and their associations with clinicopathological features, as well as tumor-specific survival (TSS), were investigated. Receiver operating characteristic curves were generated to determine the cutoff values for pSTAT3 and Ki-67 using Youden's index as the criterion. All FMCs positively immunolabeled for tSTAT3 and pSTAT3. Significant associations were observed between the pSTAT3 index and the WHO clinical stage, lymph node metastasis, and lymphovascular invasion. However, no significant associations were established with any other factors. Using the cutoff value to classify the pSTAT3 index, the higher pSTAT3 index (>25.2%) was significantly associated with decreased TSS (P = .00570). No significant associations were established between the Ki-67 index and any of the factors. Also, a significant positive association was observed between the pSTAT3 and Ki-67 indexes (P = .0001). This significant association with TSS underscores the potential role of pSTAT3 as a prognostic marker in FMC.

Nine wild American white ibis (Eudocimus albus) were found deceased or were moribund and subsequently euthanized within 24 hours after exposure to theatrical fog containing propylene glycol and triethylene glycol at a Halloween event at a zoological institution. Gross examinations revealed that all birds had congestion, edema, and hemorrhage throughout the lungs. Histologically, all birds had pathologic changes within the trachea and lungs indicative of acute respiratory insult. Microscopic changes in the trachea included segmental to diffuse epithelial attenuation with loss of cilia, alternating with regions of goblet cells filled with abundant mucus. In the lungs, all birds had perivascular edema and degenerative changes to the epithelium lining primary and secondary bronchi including hypereosinophilia and apical cytoplasmic blebbing of bronchial epithelial cells. In addition, in the lungs of 4 birds with longer intervals between exposure and death, there was granulomatous pneumonia, heterophilic perivascular cuffing, and multifocal bronchial epithelial necrosis. Propylene glycol and triethylene glycol were detected in lung and kidney tissues by gas chromatography-tandem mass spectrometry (GC-MS/MS). Traces of oxalic acid were found, along with presence of glycolic acid. While exposure to aerosolized glycols has been shown to cause irritation and minor degenerative changes to the respiratory epithelium in laboratory animals and humans, this study represents a unique investigation into the first reported incidence of acute inhalation toxicity and death following exposure to aerosolized glycol-containing theatrical fog in birds.

Zoonotic poxviruses, including monkeypox virus (MPV), the causative agent for Mpox disease, have gained significant media and scientific attention due to recent outbreaks in human populations across the globe. The increase in human cases of poxvirus infection is not unexpected, as routine vaccination against smallpox (a disease caused by the poxvirus variola virus, which cross protects against other orthopoxviruses) was discontinued in the 1980s after its eradication. Large numbers of vertebrate and invertebrate species are susceptible to infection by Poxviridae. Clinical signs and histologic lesions caused by genetically different poxviruses can be strikingly similar with some notable exceptions (eg, poxviral infections in fish). The purpose of this article is to review poxvirus pathology and pathogenesis observed in species of agricultural significance including poultry, cattle, goats, sheep, camels, swine, rabbits, horses, salmon, and carp.

The mononuclear phagocyte system (MPS) is an ensemble of heterogeneous cells comprising circulating monocytes, macrophages, and dendritic cells. Immunohistochemistry is a valuable technique to detect, quantify, and localize MPS cells in tissues, but a comprehensive characterization of MPS cells in normal tissues of mice is lacking to date. The aim of this study was to immunohistochemically characterize MPS cells in a set of murine healthy tissues and in a subset of representative disease states. Sections of healthy tissues obtained from 21 C57BL/6J and C57BL/6N mice and sections of inflammatory (necrosuppurative hepatitis and Pneumocystis murina-associated pneumonia) and experimentally induced neoplastic conditions (human fibrosarcoma xenograft and mammary carcinoma syngraft) were immunolabeled with a panel of MPS markers, including IBA1, F4/80, macrophage receptor with collagenous structure (MARCO), CD206, arginase 1, Ym1, induced nitric oxide synthase, heme-oxygenase 1 (HO-1), and class II major histocompatibility complex (MHC-II). For each tissue, the amount, morphology, location, and immunolabeling intensity of positive cells were evaluated using semi-quantitative scores. Results highlighted the morphological and immunophenotypic heterogeneity of murine MPS cells. The panel of antibodies used allowed for discrimination of different cell populations across the examined tissues based on immunophenotype, microanatomical location, and morphology, providing useful morphological and functional clues on MPS cells in both physiological and diseased conditions. The results of this study provide a valuable reference regarding the amount, morphology, microanatomical location, and immunophenotype of MPS subsets in healthy murine tissues. In addition, it highlights the plasticity of these cells in inflammatory and neoplastic settings, underscoring the importance of a comprehensive characterization of MPS cells in physiological and disease states.

In October 2020, adult male and female NSG (NOD. Cg-Prkdc^scid Il2rg^tm1Wjl/Sz) mice were reported for diarrhea within a mouse barrier facility. Other immunodeficient strains harboring the SCID (Prkdc^scid) or Rag (Rag^null) mutations together with the IL2rg (Il2rg^null) mutation were affected. At its peak, over 20 laboratories in 10/16 (62.5%) barrier rooms were affected. Mortality was rare except in lactating females (≥ P11). Grossly, nonlactating adult female and male mice (n = 16) had mild to moderate, small and large intestinal distension with corresponding individual cell death and sloughing of superficial enterocytes in the cecocolonic mucosa. Lactating NSG dams (n=6) had moderate to severe gastrointestinal distension and/or segmental, dark red to gray, small intestinal discoloration. In addition to the same histologic lesions seen in nonlactating female NSG mice, lactating NSG dams often had severe ulcerative inflammation affecting the jejunum, ileum, cecum, and colon. Traditional ancillary diagnostic tests including aerobic and anaerobic cultures (blood, liver, spleen, and intestines), fecal PCR, and fecal floatation failed to yield a causative organism. Further cohousing and oral gavage studies determined neither immunocompetent CD1 (Crl:CD1 [ICR]) mice nor immunodeficient NOD scid (NOD.Cg-Prkdc^scid/J) and Rag2 KO (C57BL/6. Cg-Rag2^tm1.1Cgn/J) mice were susceptible to clinical disease. Extensive control barriers were implemented including a veterinary-managed NSG breeding barrier, alterations in husbandry practices, and strategic environmental disinfection, allowing for continuity of experimental studies while avoiding widespread depopulation of the barrier. Subsequent strain-resolved metagenomics and qPCR assay development identified Clostridium cuniculi and its enterotoxin exclusively within diarrheic mice.

This study aims to provide an in-depth examination of the histological changes that occur during the repair of untreated bone fractures in avian species, correlating these microscopic alterations with gross anatomical characteristics observed during different tissue repair phases. A total of 93 bone fractures from different wild birds were analyzed and classified based on temporality (acute, subacute, and chronic) according to the color changes of the hematoma and morphology (open or closed; simple, comminuted, or greenstick fractures). From a microscopic standpoint, a strong correlation was observed between the temporal progression observed macroscopically and the histological changes evident in each temporal category. Microscopic variations were found to depend on the nature of the fracture. Lesional patterns directly related to the macroscopic appearance of the fracture were established. Acute fractures exhibited extensive hematomas and an intense inflammatory response; subacute fractures showed immature granulation tissue and early signs of soft callus formation; and finally, chronic fractures were characterized by prominent soft calluses and hard calluses in different stages of development. The possible factors influencing each phase of the healing process, such as the characteristics of the type of fracture, the stability of the fracture site, bacterial contamination, the chronicity of the fracture, and the potential differences in the progression of histological changes between different animal species, are discussed. This association may be of clinical utility in decision-making for the treatment and prognosis of bone fractures in birds.