Veterinary Pathology最新文献

Although waterfowl are less susceptible to Newcastle disease (ND) virus (NDV) infection compared with chickens and turkeys, lethal ND in waterfowl has been sporadically reported. Factors underlying the high pathogenicity of certain NDV strains in waterfowl remain unclear. In ducks, the NDV 9a5b isolate shows low pathogenicity while the d5a20b isolate shows high pathogenicity. This study aimed to identify the definitive lesions that led to the lethal virulence of d5a20b by comparing the histopathology of 9a5b- or d5a20b-inoculated ducks in order to elucidate lesions related to the enhanced pathogenicity of certain NDV strains in ducks. Herein, 7-day-old ducks were intranasally inoculated with either 9a5b or d5a20b NDV strains. The neurological signs were more severe in the d5a20b-inoculated group than in the 9a5b-inoculated group. Ducks in the d5a20b-inoculated group exhibited more severe lymphoid depletion in immune organs than those in the 9a5b-inoculated group, which may have caused an immunosuppressive state in the d5a20b-inoculated ducks. Ducks in the d5a20b-inoculated group had more severe nonsuppurative encephalitis with increased NDV nucleoprotein than those in the 9a5b-inoculated group. Additionally, pancreatic necrosis, with intralesional NDV nucleoprotein, was more severe in the d5a20b-inoculated group than in the 9a5b-inoculated group. Our results showed that the immune organs, brain, and pancreas were significant targets of the NDV d5a20b infection in ducks.

Variation in nuclear size and shape is an important criterion of malignancy for many tumor types; however, categorical estimates by pathologists have poor reproducibility. Measurements of nuclear characteristics can improve reproducibility, but current manual methods are time-consuming. The aim of this study was to explore the limitations of estimates and develop alternative morphometric solutions for canine cutaneous mast cell tumors (ccMCTs). We assessed the following nuclear evaluation methods for accuracy, reproducibility, and prognostic utility: (1) anisokaryosis estimates by 11 pathologists; (2) gold standard manual morphometry of at least 100 nuclei; (3) practicable manual morphometry with stratified sampling of 12 nuclei by 9 pathologists; and (4) automated morphometry using deep learning-based segmentation. The study included 96 ccMCTs with available outcome information. Inter-rater reproducibility of anisokaryosis estimates was low (k = 0.226), whereas it was good (intraclass correlation = 0.654) for practicable morphometry of the standard deviation (SD) of nuclear size. As compared with gold standard manual morphometry (area under the ROC curve [AUC] = 0.839, 95% confidence interval [CI] = 0.701-0.977), the prognostic value (tumor-specific survival) of SDs of nuclear area for practicable manual morphometry and automated morphometry were high with an AUC of 0.868 (95% CI = 0.737-0.991) and 0.943 (95% CI = 0.889-0.996), respectively. This study supports the use of manual morphometry with stratified sampling of 12 nuclei and algorithmic morphometry to overcome the poor reproducibility of estimates. Further studies are needed to validate our findings, determine inter-algorithmic reproducibility and algorithmic robustness, and explore tumor heterogeneity of nuclear features in entire tumor sections.

Pigment-containing and light-reflecting cell neoplasms, generically termed chromatophoromas, affect fish, reptiles, and amphibians. Chromatophoromas of light-reflecting cells are named iridophoromas. In this study, we aimed to describe the gross, histologic, and ultrastructural findings of 71 cases of iridophoromas in farmed Siamese fighting fish (Betta splendens). Macroscopically, iridophoromas appeared as whitish, gray, or black friable masses or plaques in the fin, trunk/tail, or head of the fish. Forty-five tumors (63%) were malignant and invaded the adjacent skeletal muscle and/or metastasized to other organs, whereas 26 (37%) tumors were restricted only to the skin, but due to the cytologic similarity to the malignant counterpart, we were not able to classify them as malignant or benign. Sixty-five (91%) tumors were classified as iridophoromas, whereas 6 (8%) were diagnosed as mixed chromatophoromas. Despite immunolabeling for PNL-2, melan A, or S-100 failing to demonstrate antigen expression, ultrastructural analysis identified light-reflecting neoplastic cells, unequivocally confirming iridophoromas as the predominant tumor. The high incidence of iridophoromas in Siamese fighting fish from the same breeding facility, coupled with a higher occurrence in royal blue and fancy copper color patterns and in young males, suggests a potential genetic/hereditary factor in the tumorigenesis of these neoplasms.

Amyloidosis is a group of diseases in which proteins become amyloid, an insoluble fibrillar aggregate, resulting in organ dysfunction. Amyloid deposition has been reported in various animal species. To diagnose and understand the pathogenesis of amyloidosis, it is important to identify the amyloid precursor protein involved in each disease. Although 42 amyloid precursor proteins have been reported in humans, little is known about amyloidosis in animals, except for a few well-described amyloid proteins, including amyloid A (AA), amyloid light chain (AL), amyloid β (Aβ), and islet amyloid polypeptide-derived amyloid. Recently, several types of novel amyloidosis have been identified in animals using immunohistochemistry and mass spectrometry-based proteomic analysis. Certain species are predisposed to specific types of amyloidosis, suggesting a genetic background for its pathogenesis. Age-related amyloidosis has also emerged due to the increased longevity of captive animals. In addition, experimental studies have shown that some amyloids may be transmissible. Accurate diagnosis and understanding of animal amyloidosis are necessary for appropriate therapeutic intervention and comparative pathological studies. This review provides an updated classification of animal amyloidosis, including associated protein misfolding disorders of the central nervous system, and the current understanding of their pathogenesis. Pathologic features are presented together with state-of-the-art diagnostic methods that can be applied for routine diagnosis and identification of novel amyloid proteins in animals.

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.

Dermoid cysts are developmental abnormalities usually located at the dorsal body midline. Histologically, these lesions reduplicate the skin, with associated collagen bundles, adnexal structures, and are filled by keratin and hairs. While these cysts have well-recognized breed and anatomical predispositions in dogs, the information in feline patients is restricted to scattered case reports and anecdotal data. Through a multi-institutional retrospective case series, we aim to describe the clinical and demographic features of this condition in cats. We retrieved a total of 220 cases. The average age at the time of diagnosis was 5.5 years, with 59.5% (131/220) being males. Domestic short hairs were the most represented breed, accounting for 56.4% (124/220) of the cases. The average cyst diameter was 1.4 cm, and 99.5% (219/220) of the cases the cysts were cutaneous and subcutaneous with the most common anatomical location being the neck (55.9%; 123/220). One dermoid cyst was in the mesentery. In most cases, no associated inflammatory lesions were reported (66.4%; 146/220). The anatomical location of the dermoid cyst did not differ significantly among sexes (Chi-square test, P = .840), breeds (Chi-square test, P = .999), ages (Chi-square test, P = .627), or other histological findings related to the cyst (Chi-square test, P = .363).

Splenic masses are common in dogs and vary dramatically in their clinical behavior. Clinically, and even with histology, it can be challenging to differentiate between benign and malignant splenic masses. Hemangiosarcoma (HSA), the most common malignancy of the spleen, is a very aggressive tumor with a poor prognosis. We hypothesize that microRNAs (miRNAs) in mass tissue and serum can differentiate between HSA and other splenic masses. Fifty-nine miRNAs were investigated by reverse-transcription followed by real-time quantitative polymerase chain reaction (RT-qPCR) in serum and/or tissue from dogs with HSAs (serum n = 24 and tissue n = 17; postsplenectomy serum n = 11), lymphomas (serum n = 8 and tissue n = 11), nonangiomatous nonlymphomatous sarcomas (serum n = 6 and tissue n = 10), histiocytic sarcomas (tissue n = 4), benign splenic masses (myelolipomas, nodular hyperplasia, and hematomas; total serum n = 21 and total tissue n = 35), and normal dogs (serum n = 14 and tissue n = 7). Numerous miRNAs were differentially expressed in serum and tissue of HSA cases compared to those with other splenic masses or normal spleens. In serum, our 5-miRNA model (miR-135a-5p, miR-10a, miR-450b, miR-152-3p, and miR-126-5p) accurately classified 100% (24/24) of dogs with HSA from normal dogs and those with a benign splenic mass (recall = 1 for HSA). The overall accuracy of the model was 86%. In HSA and benign splenic mass tissues, our 3-miRNA model (miR-126-5p, miR-502-3p, and miR-452-5p) accurately classified 96% of the cases. This study demonstrates the utility of miRNA models in serum and tissue for screening and diagnosis of HSA in dogs. Future studies include the evaluation of prospective and prediagnosis serum samples.