Veterinary Pathology最新文献

Canine neoplasms of the diffuse neuroendocrine system are an enigmatic and heterogeneous group of neoplasms with a wide spectrum of immunohistochemical properties and morphologic features. Through the utilization of tissue microarrays, 82 canine neoplasms of the disseminated neuroendocrine system from 16 different anatomic locations were evaluated. The prototypical canine neoplasm of the disseminated neuroendocrine system was composed of rounded polygonal neoplastic cells arranged in packets supported by delicate fibrovascular stroma. Neoplastic cells typically had moderate quantities of pale eosinophilic cytoplasm stippled by numerous fine argyrophilic granules, round nuclei with finely stippled chromatin, and inconspicuous nucleoli. Immunohistochemical assays utilized in this study included chromogranin A, neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP2), pan-cytokeratin, oligodendrocyte transcription factor 2 (OLIG2), protein gene product 9.5 (PGP9.5), vimentin, synaptophysin, neuronal nuclei (NeuN), S100, SRY-related HMG-box 10 (SOX10), glial fibrillary acidic protein (GFAP), insulinoma-associated protein 1 (INSM1), CD56, and antigen Kiel 67 (Ki67). The 4 immunohistochemical assays that were positive in over 50% of cases included PGP9.5 (77/82, 94%), NSE (68/82, 83%), synaptophysin (59/82, 72%), and chromogranin A (56/82, 69%). In 81/82 (99%) cases, neoplastic cells immunolabeled with at least 1 of these 4 assays, and thus, these 4 immunohistochemical assays are deemed most useful when attempting to substantiate that a neoplasm is of neuroendocrine origin.

Usutu virus (USUV) is a zoonotic neurotropic arbovirus related to the West Nile virus that causes mortality in birds and sporadic neurologic human disease. Current research on natural USUV-associated disease lacks data on ocular involvement. This study investigated ocular and periocular tissue involvement in natural USUV infections and associated disease in Eurasian blackbirds (Turdus merula). Twenty-two found-dead Eurasian blackbirds were examined. USUV reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) detected 12/22 infected blackbirds. Histology and immunohistochemistry for virus antigen, inflammation (anti-CD3 for T-lymphocytes), and apoptosis (anti-cleaved caspase-3 (CC3)) assessed the virus tropism and associated damage. In the eye of USUV-infected blackbirds, choroiditis was the main finding (9/12), while the pecten oculi (4/12) and optic nerves (4/12) were occasionally affected. Virus antigen was detected in the lesions. The cornea and retina lacked virus antigens and lesions. Periocular soft tissues (12/12) and eyelids (9/12) were also affected. Lesions in the choroid (P < .001), ciliary bodies (P < .01), and sclera (P < .05) were significantly associated with USUV infection. In the choroid, CD3 and CC3 strongly correlated with the virus antigen scores (P < .0001), suggesting a T-cell response and apoptosis involvement in the ocular damage. A negative correlation was identified for the virus antigen score in choroid and eyelids with USUV RT-qPCR Ct values (P < .05). This study reports for USUV features consistent with ocular and periocular tropism and disease with a major involvement of the choroid, suggesting a primary ocular vascular spread.

Clostridium colinum causes ulcerative enteritis in several avian species. The disease is particularly prevalent in quail, and it is therefore colloquially known as quail disease. The pathogenesis of the infection is poorly understood. A retrospective study of C. colinum infection in quail submitted for necropsy and diagnostic work up to the California Animal Health and Food Safety Laboratory System between 1992 and 2022 was performed. The necropsy reports were reviewed, and polymerase chain reaction (PCR) for C. colinum (16S rRNA) was performed on formalin-fixed, paraffin-embedded tissues. C. colinum was isolated in 17% (4/24) and detected by PCR in 96% (23/24) of cases. Bobwhite quail (Colinus virginianus) were overrepresented, and the most affected quail were juveniles. Clinical history and signs were increased mortality (92%), lethargy (29%), depression (25%), diarrhea (21%), loss of nutritional condition (8%), and seizures (8%). Grossly, intestinal ulceration (100%) affecting the duodenum (79%), jejunum (100%), ileum (29%), and/or ceca (21%). Fibrinous celomitis (13%), hepatic necrosis (46%), and pectoral muscle atrophy (92%) were observed. Histologically, all quail showed multifocal ulcerative jejunitis, duodenitis, ileitis, and/or typhlitis with intralesional bacilli. Ulcerative enteritis was transmural in 92% of cases, associated with intestinal perforation in 38%, and causing celomitis in 50% of cases. Hepatic necrosis was confirmed in 63% of cases, and neuronal changes suggesting a combination of hypoxia-ischemia and hypoglycemia were found in 63% of cases. These results suggest that a diagnosis of C. colinum infection should be made based on gross and microscopic lesions, coupled with PCR.

A 6-year-old, castrated male, domestic shorthair cat with progressive neurologic signs underwent magnetic resonance imaging, revealing a suprasellar mass, which resulted in euthanasia. Grossly, a tan-red tumor expanded the ventral third ventricle, compressed adjacent brain structures, and emerged ventrally at the midline. Histologically, numerous arborizing papillary formations protruded into a network of anastomosing luminal canals. Neoplastic cells immunolabeled for pan-cytokeratin, vimentin, and E-cadherin, and lacked immunolabeling for oligodendrocyte transcription factor 2 (OLIG2), glial fibrillary acidic protein (GFAP), and adrenocorticotropic hormone (ACTH). Transmission electron microscopy revealed apical microvilli, apical and lateral tight junctions, and a basal membrane. In this cat, the neuroanatomic location with ventral brain invasion was more suggestive of ependymal origin; however, there were overlapping histologic and immunohistochemical features, and ultrastructural features were more consistent with choroid plexus epithelium. Dual ependymal and choroid plexus differentiation could not be excluded. This case highlights species differences in both the occurrence and neurolocalization of intraventricular tumors in domestic animals and comparable features between papillary ependymoma and choroid plexus papilloma.

Paratuberculosis is an infection with Mycobacterium avium ssp. paratuberculosis (MAP) causing chronic enteritis in domestic and wild ruminants worldwide. In goats, the infection is caused by C (cattle)-type and S (sheep)-type strains. In this study, the correlation between different MAP strains and histomorphological lesions in the small and large intestines, as well as the mesenteric lymph nodes, in Swiss goats (Caprae aegagrus hircus) was investigated. Ten Swiss caprine MAP isolates were characterized using polymerase chain reaction (PCR) and enzymatic restriction-based single nucleotide polymorphism (SNP) analysis. In addition, mycobacterial interspersed repetitive units and variable-number tandem repeats (MIRU-VNTR) profiling was performed, and the correlation with histologic lesions, scored as previously described for goats, was analyzed. Furthermore, immunohistochemical expression of CD3, CD79a, Iba1, cleaved caspase 3, and interleukin (IL)-17 was evaluated, and a morphometric analysis was conducted to quantify the different inflammatory cells. Diffuse multibacillary lesions were found in C-type/L'Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE) Nouzilly MIRU-VNTR (INMV)1 (2/10) and S-type/INMV220 (1/10) animals. Diffuse lymphocytic lesions occurred in C-type/INMV1 (2/10) animals, while diffuse mixed lesions were observed in S-type/INMV218 (3/10) and S-type/INMV220 (2/10) animals. No significant differences in intestinal histological lesion scores were detected between S- and C-type INMV strains. Morphometrical analysis revealed similar inflammatory and apoptotic cell numbers in the intestinal mucosa of C- and S-type animals; however, S-type animals exhibited significantly more Iba1- and cleaved caspase 3-positive cells in mesenteric lymph nodes. Lesions in mesenteric lymph nodes might indicate a differentially regulated course in MAP pathogenesis.

A 7-year-old mixed-breed cat presented with intermittent dry cough for 2 years. Histological examination of the lung biopsy revealed hyperplasia of bronchial and bronchiolar epithelium, and intraepithelial infiltration of globule leukocytes in many bronchi, bronchioles, and terminal bronchioles. Lymphoid aggregates cuffed airways, respiratory bronchioles, and alveolar ducts. Terminal airway inflammation was associated with type II pneumocyte hyperplasia within adjacent alveoli. Warthin-Starry stain revealed numerous argyrophilic and filamentous bacilli that were interspersed or clustered with cilia of the respiratory epithelium. The morphology, distribution, and gram (negative) and ultrastructural characteristics were consistent with cilia-associated respiratory (CAR) bacillus. Real-time polymerase chain reaction assays using paraffin-embedded lung tissue confirmed the presence of Filobacterium felis. Chronic bronchitis and bronchiolitis in a cat with F. felis share characteristics of diseases caused by species specific CAR bacilli in many species, but uniquely in this case, globule leukocytes were a prominent feature of the inflammatory response.

Different tissues have a normal color spectrum that reflects their cellular composition and/or metabolic features. Similarly, distinct color variations may occur in tissues that have undergone pathologic or nonpathologic changes. Common examples of color changes in domestic animal tissues include red (associated with erythrocytes, hemoglobin, and myoglobin), brown (ferric hemoglobin or myoglobin, suppurative inflammation, lipid oxidation, postmortem autolysis, formalin fixation, neoplasms arising from cytochrome-rich tissues), yellow (hemoglobin and iron degradation, biliary pigment and by-products, carotenes, keratin, necrosis, suppurative or fibrinous inflammation), green (hemoglobin and iron degradation, biliary pigment and by-products, meconium, eosinophilic or suppurative inflammation, oomycete and algal infections), white (lack of blood, adipose tissue and its neoplasms, chylous effusion, necrosis, mineralization, fibrosis, lymphoid tissue, round cell neoplasms), translucent (transudate, cysts), black to gray (hemoglobin and iron degradation, melanin, carbon, tattoos), and blue to purple (poorly oxygenated blood, tattoos). Pathologists and pathology trainees can benefit from understanding why particular colors are present in a tissue or organ and are advised to recognize the color dynamics that occur over time, such as hemorrhage progressing from red to purple and subsequently to yellow, green, and brown. Therefore, clear and precise color recognition and description is a key feature of a gross examination. Understanding the relationship between color changes in tissues and the underlying biologic or pathologic processes can help elucidate disease recognition and diagnosis.

Numerous prognostic factors are currently assessed histologically and immunohistochemically in canine mast cell tumors (MCTs) to evaluate clinical behavior. In addition, polymerase chain reaction (PCR) is often performed to detect internal tandem duplication (ITD) mutations in exon 11 of the c-KIT gene (c-KIT-11-ITD) to predict the therapeutic response to tyrosine kinase inhibitors. This project aimed at training deep learning models (DLMs) to identify MCTs with c-KIT-11-ITD solely based on morphology. Hematoxylin and eosin (HE) stained slides of 368 cutaneous, subcutaneous, and mucocutaneous MCTs (195 with ITD and 173 without) were stained consecutively in 2 different laboratories and scanned with 3 different slide scanners. This resulted in 6 data sets (stain-scanner variations representing diagnostic institutions) of whole-slide images. DLMs were trained with single and mixed data sets and their performances were assessed under stain-scanner variations (domain shifts). The DLM correctly classified HE slides according to their c-KIT-11-ITD status in up to 87% of cases with a 0.90 sensitivity and a 0.83 specificity. A relevant performance drop could be observed when the stain-scanner combination of training and test data set differed. Multi-institutional data sets improved the average accuracy but did not reach the maximum accuracy of algorithms trained and tested on the same stain-scanner variant (ie, intra-institutional). In summary, DLM-based morphological examination can predict c-KIT-11-ITD with high accuracy in canine MCTs in HE slides. However, staining protocol and scanner type influence accuracy. Larger data sets of scans from different laboratories and scanners may lead to more robust DLMs to identify c-KIT mutations in HE slides.

Chlamydia pecorum causes subclinical infections in cattle, but sporadic, bovine encephalomyelitis cases have been reported in calves and documented in two instances in European buffalo. An outbreak of Chlamydia pecorum-induced encephalomyelitis and serositis occurred in 3-month-old buffalo calves from Brazil. Initially presenting with pelvic limb incoordination, the calves progressed to lateral recumbency, depression, and death. Necropsies of two calves revealed encephalomyelomalacia, fibrin deposition on the external surface of the pericardium (case 1) and pleural and pericardial fibrosis (case 2). Microscopically, a multifocal to coalescing, necrotizing, neutrophilic and lymphocytic meningoencephalomyelitis with fibrinoid vasculitis and thrombosis was present. Anti-Chlamydia antibody labeling was demonstrated by immunohistochemistry. Bacteriological examination yielded no pathogenic bacteria in the brain or lungs. Chlamydia pecorum was confirmed by PCR. This work describes the gross, histopathological, microbiological, and molecular findings in two cases from an outbreak of Chlamydia pecorum-induced disease in buffalo calves.