Journal of Comparative Pathology最新文献

{"title":"Histomorphological features and ezrin expression in testicular seminomas in dogs: an association with potential prognostic value","authors":"Sara C. Pereira de Souza ,&nbsp;Maurício D. de Barros ,&nbsp;Bárbara P. dos Santos Batista ,&nbsp;Camila B. Amaral ,&nbsp;Ana M. Reis Ferreira ,&nbsp;Juliana da Silva Leite","doi":"10.1016/j.jcpa.2026.02.003","DOIUrl":"10.1016/j.jcpa.2026.02.003","url":null,"abstract":"<div><div>Seminoma (SEM) is one of the most frequent testicular neoplasms in dogs, originating from germ cell lineage of the seminiferous tubule and divided into diffuse and intratubular patterns, according to location. Periodic acid–Schiff (PAS) staining is used to classify human SEMs but there is no consensus regarding canine SEMs. Ezrin expression has been detected in several human neoplasms and is linked to a poor prognosis. However, its expression in testicular tumours is rarely described in human SEMs and no similar study was found in dogs. This study aimed to evaluate the presence of ezrin by immunohistochemical labelling and PAS staining in canine SEM samples, correlating them with histomorphological features. Twenty-three canine SEMs were subjected to PAS staining and anti-ezrin immunohistochemical analysis. Pink-magenta-stained samples were PAS positive. Percentage of ezrin immunolabelled positive cells, immunolabelling intensity and ezrin location were recorded. Intratubular SEMs were PAS positive but diffuse samples were PAS negative. Twenty cases (87%) were ezrin positive by cytoplasmic immunolabelling. Ezrin immunolabelling intensity was heterogeneous among tumour samples, similar to normal testicular tissue, but with different locations in each case. The percentage of positive cells was high in 18 cases and correlated positively with diffuse SEM. Ezrin immunolabelling correlated with cytoplasmic immunolocalisation, intensity and percentage of immunolabelled cells. This study confirmed differences in PAS staining for canine SEM patterns and ezrin immunolabelling in diffuse and intratubular canine SEMs, demonstrating ezrin's potential role in this testicular tumour in dogs. Diffuse canine SEM had local invasive features associated with ezrin immunolabelling. According to these findings, PAS staining correlates with canine SEM histomorphology and ezrin immunolabelling can be used as a biological marker of the local invasiveness potential of canine SEMs.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"226 ","pages":"Pages 57-63"},"PeriodicalIF":0.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147592577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malignant ovarian granulosa cell tumour of corpus luteum origin in a California sea lion (Zalophus californianus)","authors":"Nancy Stedman ,&nbsp;Eric Gibbons ,&nbsp;Brittany Dolan ,&nbsp;Kara Abbott ,&nbsp;Jennifer Russell ,&nbsp;Todd Schmitt ,&nbsp;Kelsey Herrick","doi":"10.1016/j.jcpa.2026.03.001","DOIUrl":"10.1016/j.jcpa.2026.03.001","url":null,"abstract":"<div><div>A 19-year-old female California sea lion (<em>Zalophus californianus</em>) in managed care was euthanized following a 3-week history of hyporexia, diarrhoea, lethargy, abdominal discomfort, dyspnoea and tremors. Ante-mortem ultrasound confirmed splenomegaly with multifocal infiltrates and splenic aspirates revealed malignant cells of undetermined origin. Necropsy confirmed a malignant trabecular to diffuse granulosa cell tumour (GCT) that had metastasized to the liver, spleen, kidneys, adipose tissue, pancreas, adrenal glands, lungs, lymph nodes, brain and bone marrow. The GCT was arising within a corpus luteum and was not causing ovarian enlargement. A reticulin stain was useful to distinguish neoplastic granulosa cells from non-neoplastic cells of the corpus luteum. All neoplastic granulosa cells expressed vimentin and cytokeratin but few expressed inhibin alpha. The GCT had a mitotic count of 17 per 2.37 mm² and a Ki67 index of 85%. The sea lion delivered a stillborn pup 5 months prior to euthanasia, indicating the interval from tumour onset to severe metastatic disease was less than 5 months. The aggressive behaviour, high proliferation indices, origin of the neoplasm in a corpus luteum and lack of ovarian enlargement are unusual features for a GCT.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"226 ","pages":"Pages 20-23"},"PeriodicalIF":0.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147504149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A retrospective study (2019-2024) of neoplastic and non-neoplastic lesions in biopsy samples from exotic pet mammals in Hong Kong","authors":"Manar AbdelMageed ,&nbsp;Fraser I. Hill ,&nbsp;Jia Geng ,&nbsp;Fan Luo ,&nbsp;Wenzong He ,&nbsp;May Tse ,&nbsp;Steve Mills ,&nbsp;John Jardine ,&nbsp;Colin T. McDermott ,&nbsp;Ibrahim Elsohaby","doi":"10.1016/j.jcpa.2026.03.002","DOIUrl":"10.1016/j.jcpa.2026.03.002","url":null,"abstract":"<div><div>This retrospective study analysed pathological findings in tissue biopsies from eight exotic pet mammal species submitted to the CityU Veterinary Diagnostic Laboratory in Hong Kong between January 2019 and December 2024. Tissue biopsies were submitted from 287 rabbits, 161 hamsters, 131 hedgehogs, 64 guinea pigs, 22 chinchillas, 20 rats, seven mice and six ferrets. Across all investigated species, both neoplastic and non-neoplastic lesions were prevalent with species-specific tendencies in affected organ system. Skin and soft tissues, along with the reproductive system, were the most affected organ system in all investigated species. Except for chinchillas, neoplastic lesions outnumbered non-neoplastic lesions in all studied species. Adenocarcinoma (15.2%) mostly of the uterus and mammary gland was the most commonly diagnosed lesion in rabbits followed by trichoblastoma (14.5%). Adenoma (14.6%), mostly of the mammary gland, was the most frequently submitted lesion from hamsters, followed by lymphoma (9.8%). Sarcomas of uncertain differentiation were the most prevalent lesions in hedgehogs (21.4%) and were primarily cutaneous and uterine sarcomas, while cystic endometrial hyperplasia (CEH) ranked second (15.3%). In guinea pigs, CEH (21.5%) was the most commonly identified pathology followed by mammary adenoma (13.8%). The reproductive system accounted for more than half of the lesions diagnosed in chinchillas with CEH and endometritis being the most prevalent lesions, each representing 18.2% of submitted biopsies from chinchillas. Mammary gland fibroadenoma was the most frequent diagnosis in rats (55%) and equal in frequency with adenocarcinoma in mice, each representing 25% of submitted biopsies. Ferrets had seven distinct diagnoses. These findings emphasize the significance of reproductive and integumentary health in exotic pet mammals and reveal species-specific disease patterns critical for diagnosis and preventive care.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"226 ","pages":"Pages 24-37"},"PeriodicalIF":0.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147512331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ganglioneuroma in a Meller's chameleon (Trioceros melleri)","authors":"Freelie Mitchell ,&nbsp;Mary Ceccolini ,&nbsp;Robert V. Jones ,&nbsp;Elise E.B. LaDouceur","doi":"10.1016/j.jcpa.2026.01.008","DOIUrl":"10.1016/j.jcpa.2026.01.008","url":null,"abstract":"<div><div>Nervous system neoplasia is rarely reported in reptiles, with most reports representing gliomas. A captive, 9-year-old Meller's chameleon (<em>Trioceros melleri</em>) was euthanized for weight loss and lethargy. At necropsy, a 2 cm-diameter mass was effacing the right adrenal gland and adhered to the kidney. The skin had two, 0.8–1.0 cm-diameter, firm, pale-yellow masses over the right leg and left shoulder. The fat bodies were small. Histologically, the adrenal gland and peri-adrenal soft tissues were effaced by an expansile, moderately cellular neoplasm entrapping remnant chromaffin and interrenal cells and invading the kidney. The neoplasm was composed of two cell populations resembling well-differentiated neurons and Schwann cell-like peripheral nerve sheath elements. Cellular atypia was minimal. The skin was multifocally elevated and expanded by invasive, unencapsulated neoplasms composed of intersecting streams of neoplastic spindle cells with abundant eosinophilic, finely vacuolated cytoplasm, oval nuclei, marked anisocytosis and anisokaryosis, and occasional mitoses; these were interpreted as sarcomas. The fat bodies had marked atrophy. Immunohistochemistry was non-contributory (glial fibrillary acidic protein, neuron-specific enolase, synaptophysin, NeuN, chromogranin, S100 and vimentin) or negative (AE1/AE3) in neoplastic cells. The adrenal gland mass was diagnosed as a ganglioneuroma, which is a neoplasm of the peripheral nervous system originating from the sympathetic ganglia of the autotomic nervous system. Ganglioneuroma is rarely reported in veterinary species, and this is the first report in a reptile. The origin of this ganglioneuroma was likely neural crest cells of the adrenal gland. It is unknown whether the dermal masses were related to the ganglioneuroma or were unrelated sarcomas.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"226 ","pages":"Pages 38-41"},"PeriodicalIF":0.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147521204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of the pathology of herpesvirus infections in pinnipeds","authors":"Amy L. Robinson ,&nbsp;Laura Bianchessi ,&nbsp;Mara S. Rocchi ,&nbsp;Mark P. Dagleish","doi":"10.1016/j.jcpa.2026.01.007","DOIUrl":"10.1016/j.jcpa.2026.01.007","url":null,"abstract":"<div><div>Twenty-two herpesviruses, all within the family <em>Orthoherpesviridae</em> and belonging to the <em>Alphaherpesvirinae</em> (n = 3) and <em>Gammaherpesvirinae</em> (n = 19) subfamilies have been reported in 14 different pinniped species (n = 8 phocids, n = 5 otariids and n = 1 odobenid). This review critically assessed the purported pathology reported for herpesvirus infections and found a variety of lesions present dependent on both the herpesvirus and host species. Lesions included hepatic and adrenal necrosis, interstitial pneumonia, thyroid atrophy, lymphodepletion, lymphocytolysis, ulcerative stomatitis, glossitis with tonsilitis and dermatitis, necrotizing keratitis and, potentially, other ocular lesions also. Furthermore, specific individual gammaherpesvirus infections were linked to oncogeneses including urogenital carcinoma, diffuse large B cell lymphoma and B cell lymphoblastic lymphoma. However, for many herpesvirus infections the clinical significance, lesion association and definitive herpesvirus classification remain uncertain, the latter due to lack of sufficient genome data. For these reasons, identification of the definitive host species or even if separately reported herpesviruses are actually the same virus, remain challenging. More extensive genome sequencing is required to definitively identify and classify individual herpesvirus species along with sensitive and specific tools to visualize them within tissues to enable investigation of lesion association.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"226 ","pages":"Pages 42-56"},"PeriodicalIF":0.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147521122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-communicating abomasal (gastric) diverticulum in a 7-day-old bull calf: a case report","authors":"Cassandra M. Powers","doi":"10.1016/j.jcpa.2026.02.002","DOIUrl":"10.1016/j.jcpa.2026.02.002","url":null,"abstract":"<div><div>A gastric diverticulum (GD) is defined as an outpouching of the gastric wall and is reported rarely in humans, cats and dogs. A congenital GD (true GD) is a full-thickness diverticulum involving all gastric layers. A 7-day-old bull calf with a history of sudden death was presented for post-mortem examination to the Purdue Animal Disease Diagnostic Laboratory. On gross examination, arising from the wall of the caudal aspect of the greater curvature of the abomasum was a soft to firm hollow mass with no gross evidence of communication with the abomasal lumen. Histological sections of the mass revealed a full-thickness GD that possessed all four layers of the abomasum including segments of normal abomasal epithelium. The rumen, reticulum and omasum remain undeveloped at birth and during the first few weeks of life. A calf's rumen usually develops fully at around 12 weeks of age and the abomasum does not reach its maximum volume until around 1.5 years of age. Therefore, it is possible that this calf was either born with this anomaly or it may have developed and closed completely during early post-natal development of the forestomaches. As far as the author is aware, this is the first reported case of an abomasal diverticulum in a bovid.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"225 ","pages":"Pages 10-12"},"PeriodicalIF":0.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147321585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to ‘Multiple congenital pulmonary malformations in a black-capped Bolivian squirrel monkey (Saimiri boliviensis boliviensis)’ [J Comp Pathol, 222 (2025) 3–7]","authors":"Mayane Faccin,&nbsp;Sarah M. Kezar","doi":"10.1016/j.jcpa.2026.01.011","DOIUrl":"10.1016/j.jcpa.2026.01.011","url":null,"abstract":"","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"225 ","pages":"Page 4"},"PeriodicalIF":0.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146165527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clear cell squamous cell carcinoma in the third eyelid of a horse","authors":"Daniel R. Rissi,&nbsp;Ricardo E. Mendes","doi":"10.1016/j.jcpa.2026.01.012","DOIUrl":"10.1016/j.jcpa.2026.01.012","url":null,"abstract":"<div><div>Squamous cell carcinoma (SCC) is the most common ocular and periocular neoplasm of horses, typically arising from the limbus, third eyelid mucosa or mucocutaneous junctions of the upper and lower eyelids. Tumours are locally invasive, prone to recurrence and may rarely metastasize. Histological evaluation is required for definitive diagnosis and atypical SCC subtypes may be diagnostically challenging. Here we describe a clear cell SCC in the third eyelid of a 16-year-old female Quarter Horse. The red and invasive mass was surgically excised for histological evaluation. The lesion consisted of a poorly demarcated, exophytic proliferation of neoplastic cells arranged in lobules supported by a scant stroma. Neoplastic cells had round, mostly clear cytoplasm with distinct cell borders and round to oval nuclei with coarse chromatin and a prominent nucleolus. Squamous differentiation was observed throughout. The mitotic count was 23 in 2.37 mm² (equivalent to 10 FN22/ × 40 fields). There was one area of vascular infiltration by neoplastic cells. Dysplastic epithelial plaques were observed in the adjacent third eyelid mucosa. Most neoplastic cells had no cytoplasmic staining with periodic acid–Schiff reaction and were negative for mucus and lipid using Mayer mucicarmine and Sudan IV stains, respectively. A mild degree of submucosal elastosis was observed using Verhoeff-van Gieson stain. Neoplastic cells had widespread, robust cytoplasmic labelling for pancytokeratin (AE1/AE3). Ocular or periocular clear cell SCCs have not been previously reported in domestic animals.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"225 ","pages":"Pages 1-3"},"PeriodicalIF":0.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146116343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invasive carcinoma of no special type with medullary pattern in the canine mammary gland: histopathological and immunohistochemical characterization","authors":"Lize A.B. Borges,&nbsp;Geovanni D. Cassali","doi":"10.1016/j.jcpa.2026.01.001","DOIUrl":"10.1016/j.jcpa.2026.01.001","url":null,"abstract":"<div><div>Medullary carcinoma (MC) is an extremely rare neoplasm of the human mammary gland that is essentially not reported in veterinary literature. The present report describes a case of a 14-year-old female mixed-breed dog presenting with a mammary mass. Histological examination revealed a poorly demarkated, multinodular neoplasm composed predominantly of solid sheets of epithelial cells with high nuclear-to-cytoplasmic ratio, indistinct cytoplasmic borders and marked pleomorphism. A prominent lymphoplasmacytic infiltrate was also observed. Immunohistochemical analysis showed tumour cells were positive for cytokeratin 14, 34βE12 and epidermal growth factor receptor. The tumour cells were negative for HER2 and oestrogen receptor but had diffuse labelling of progesterone receptor. The proliferation index, assessed by Ki-67 labelling, was 22%, and cyclooxygenase-2 labelling was observed in less than 10% of cells. CD3 and CD20 immunolabelling indicated a predominance of T lymphocytes within the inflammatory infiltrate. These findings led to a diagnosis of invasive carcinoma of no special type with medullary pattern and T lymphocyte enriched inflammatory infiltrate. This case reinforces the importance of recognizing MC in dogs as it shares several histopathological and immunohistochemical features with its human counterpart. Further studies with larger cohorts are needed to elucidate the prognostic significance of this rare tumour subtype in dogs.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"225 ","pages":"Pages 5-9"},"PeriodicalIF":0.9,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intestinal acinar adenocarcinoma in a blue-fronted Amazon parrot (Amazona aestiva)","authors":"João C. Krueger ,&nbsp;Carolina Fontana ,&nbsp;Arthur C. Cheng ,&nbsp;Vinicius Dahm ,&nbsp;Rachel Teixeira Neto ,&nbsp;Luana Canavessi ,&nbsp;Nelson D. Lucas ,&nbsp;Luana C. Stunitz da Silva ,&nbsp;Anderson Luiz de Carvalho ,&nbsp;Aline de Marco Viott ,&nbsp;Manoela M. Piva","doi":"10.1016/j.jcpa.2026.01.003","DOIUrl":"10.1016/j.jcpa.2026.01.003","url":null,"abstract":"<div><div>A 54-year-old captive male blue-fronted Amazon parrot <em>(Amazona aestiva)</em> was presented with progressive weight loss, diarrhoea and dyspnoea. Contrast radiographs suggested a neoplastic process by revealing an opaque soft tissue mass occupying most of the coelomic cavity. Post-mortem findings included approximately 80 ml of serous ascitic fluid. The intestines had a diffuse firm consistency, and the serosal surface was covered by multifocal to coalescent, irregularly shaped, white to off-white elevated plaques and nodules, which obscured visualization of the pancreas. Histologically, there was a neoplastic epithelial cell proliferation that extended to the intestine and pancreatic parenchyma. The cells were arranged in acini associated with mild cytoplasmic and extracellular mucin. The neoplastic cells had diffuse immunoreactivity for pancytokeratin, and both intra- and extracellular mucin stained deeply with Alcian blue. Clinical and pathological findings indicated a diagnosis of intestinal acinar adenocarcinoma.</div></div>","PeriodicalId":15520,"journal":{"name":"Journal of Comparative Pathology","volume":"224 ","pages":"Pages 30-33"},"PeriodicalIF":0.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146073856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}