Feline Pituitary Adenomas: Correlation of Histologic and Immunohistochemical Characteristics With Clinical Findings and Case Outcome.

Pituitary glands from 141 feline autopsy cases were reviewed histologically. Adenoma and hyperplasia were the most common lesions at 13 cases each. Pituitary adenoma was more likely than hyperplasia to be associated with clinical evidence of endocrinopathy or an intracranial mass (P < .001). A histochemical and immunohistochemical panel was applied to 44 autopsy- or hypophysectomy-derived pituitary adenomas in 43 cats from 2 diagnostic laboratories. Adenomas were differentiated from hyperplasia by the presence of disrupted reticulin fibers. One cat had a double (somatotroph and melanotroph) adenoma. Twenty somatotroph adenomas consisted of periodic acid-Schiff (PAS)-negative acidophils that expressed growth hormone; 16/20 had hypersomatotropism; 17/20 had diabetes mellitus. Eleven melanotroph adenomas consisted of PAS-positive basophils or chromophobes that expressed melanocyte-stimulating and adrenocorticotrophic hormones; 5/11 had hypercortisolism; 6/11 had diabetes mellitus. Eleven gonadotroph adenomas consisted of PAS-negative chromophobes that expressed follicle-stimulating and/or luteinizing hormones. Two thyrotroph adenomas consisted of PAS-negative basophils or chromophobes that expressed thyroid-stimulating hormone. Pituitary-dependent disease was not recognized in cats with gonadotroph or thyrotroph adenomas. The Ki-67 proliferation index in hypophysectomy specimens was lower in somatotroph than in melanotroph adenomas. Fourteen cats with hypophysectomy-treated somatotroph or melanotroph adenoma had an 899-day median survival time versus 173 days in 17 nonsurgical cases. After adjusting for age, adenoma size and type, hypophysectomized cats had an overall better survival time than nonsurgical cases (P = .029). The study results underscore the value of hypophysectomy and trophic hormone immunohistochemistry in the treatment and classification of feline pituitary adenomas.

International Guidelines for Veterinary Tumor Pathology: A Call to Action.

Standardization of tumor assessment lays the foundation for validation of grading systems, permits reproducibility of oncologic studies among investigators, and increases confidence in the significance of study results. Currently, there is minimal methodological standardization for assessing tumors in veterinary medicine, with few attempts to validate published protocols and grading schemes. The current article attempts to address these shortcomings by providing standard guidelines for tumor assessment parameters and protocols for evaluating specific tumor types. More detailed information is available in the Supplemental Files, the intention of which is 2-fold: publication as part of this commentary, but more importantly, these will be available as "living documents" on a website (www.vetcancerprotocols.org), which will be updated as new information is presented in the peer-reviewed literature. Our hope is that veterinary pathologists will agree that this initiative is needed, and will contribute to and utilize this information for routine diagnostic work and oncologic studies. Journal editors and reviewers can utilize checklists to ensure publications include sufficient detail and standardized methods of tumor assessment. To maintain the relevance of the guidelines and protocols, it is critical that the information is periodically updated and revised as new studies are published and validated with the intent of providing a repository of this information. Our hope is that this initiative (a continuation of efforts published in this journal in 2011) will facilitate collaboration and reproducibility between pathologists and institutions, increase case numbers, and strengthen clinical research findings, thus ensuring continued progress in veterinary oncologic pathology and improving patient care.

Brief Cognitive Tests for Distinguishing Clinical Alzheimer-Type Dementia From Mild Cognitive Impairment or Normal Cognition in Older Adults With Suspected Cognitive Impairment.

BACKGROUND: The accuracy and harms of brief cognitive tests for identifying clinical Alzheimer-type dementia (CATD) are uncertain. PURPOSE: To summarize evidence on accuracy and harms of brief cognitive tests for CATD in older adults with suspected cognitive impairment. DATA SOURCES: Electronic bibliographic databases (from inception to November 2019) and systematic review bibliographies. STUDY SELECTION: English-language, controlled observational studies in older adults that evaluated the accuracy of brief cognitive tests (standalone tests; memory, executive function, and language tests; and brief multidomain batteries) for distinguishing CATD from mild cognitive impairment (MCI) or normal cognition as defined by established diagnostic criteria. Studies with low or medium risk of bias (ROB) were analyzed. DATA EXTRACTION: Two reviewers rated ROB. One reviewer extracted data; the other verified extraction accuracy. DATA SYNTHESIS: Fifty-seven studies met analysis criteria. Many brief, single cognitive tests were highly sensitive and specific for distinguishing CATD from normal cognition. These included standalone tests (clock-drawing test, median sensitivity 0.79 and specificity 0.88 [8 studies]; Mini-Mental State Examination, 0.88 and 0.94 [7 studies]; Montreal Cognitive Assessment, 0.94 and 0.94 [2 studies]; and Brief Alzheimer Screen, 0.92 and 0.97 [1 study]), memory tests (list delayed recall, 0.89 and 0.94 [5 studies]), and language tests (category fluency, 0.92 and 0.89 [9 studies]). Accuracy was lower in distinguishing mild CATD from normal cognition and distinguishing CATD from MCI. No studies reported on testing harms. LIMITATIONS: Studies were small. Few test metrics were evaluated by multiple studies. Few studies directly compared different tests, scores, cut points, or test combinations. CONCLUSION: Many brief, single cognitive tests accurately distinguish CATD from normal cognition in older adults but are less accurate in distinguishing mild CATD from normal cognition or CATD from MCI. No studies reported on testing harms. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42018117897).

Benefits and Harms of Prescription Drugs and Supplements for Treatment of Clinical Alzheimer-Type Dementia.

BACKGROUND: Effects of drug treatment of clinical Alzheimer-type dementia (CATD) are uncertain. PURPOSE: To summarize evidence on the effects of prescription drugs and supplements for CATD treatment. DATA SOURCES: Electronic bibliographic databases (inception to November 2019), ClinicalTrials.gov (to November 2019), and systematic review bibliographies. STUDY SELECTION: English-language trials of prescription drug and supplement treatment in older adults with CATD that report cognition, function, global measures, behavioral and psychological symptoms of dementia (BPSD), or harms. Minimum treatment was 24 weeks (≥2 weeks for selected BPSD). DATA EXTRACTION: Studies with low or medium risk of bias (ROB) were analyzed. Two reviewers rated ROB. One reviewer extracted data; another verified extraction accuracy. DATA SYNTHESIS: Fifty-five studies reporting non-BPSD outcomes (most ≤26 weeks) and 12 reporting BPSD (most ≤12 weeks) were analyzed. Across CATD severity, mostly low-strength evidence suggested that, compared with placebo, cholinesterase inhibitors produced small average improvements in cognition (median standardized mean difference [SMD], 0.30 [range, 0.24 to 0.52]), no difference to small improvement in function (median SMD, 0.19 [range, -0.10 to 0.22]), no difference in the likelihood of at least moderate improvement in global clinical impression (median absolute risk difference, 4% [range, 2% to 4%]), and increased withdrawals due to adverse events. In adults with moderate to severe CATD receiving cholinesterase inhibitors, low- to insufficient-strength evidence suggested that, compared with placebo, add-on memantine inconsistently improved cognition and improved global clinical impression but not function. Evidence was mostly insufficient about prescription drugs for BPSD and about supplements for all outcomes. LIMITATION: Most drugs had few trials without high ROB, especially for supplements, active drug comparisons, BPSD, and longer trials. CONCLUSION: Cholinesterase inhibitors and memantine slightly reduced short-term cognitive decline, and cholinesterase inhibitors slightly reduced reported functional decline, but differences versus placebo were of uncertain clinical importance. Evidence was mostly insufficient on drug treatment of BPSD and on supplements for all outcomes. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality. (PROSPERO: CRD42018117897).

Diagnosis of Collagen Type III Glomerulopathy Using Picrosirius Red and PASH/Masson's Trichrome Stain.

Canine collagen type III glomerulopathy (Col3GP) is a rare juvenile nephropathy in which irregular type III collagen fibrils and fibronectin accumulate in glomerular capillary walls and the mesangium. Necropsy findings were reviewed from 5 puppies diagnosed with Col3GP at 6 to 18 weeks of age. Histologically, with hematoxylin and eosin stain, the glomerular capillary walls and mesangium were diffusely and globally expanded by homogeneous pale eosinophilic material. Ultrastructurally, the subendothelial zone and mesangium were expanded by fibronectin and cross-banded collagen type III fibrils, diagnostic of Col3GP. Two additional stains were employed to identify the material within glomeruli as fibrillar collagen using light microscopy. In all 5 cases, the material was red with picrosirius red and birefringent under polarized light, and was blue with periodic acid-Schiff/hematoxylin/trichrome (PASH/TRI), thereby identifying it as fibrillar collagen. Based on these unique staining characteristics with picrosirius red and PASH/TRI, Col3GP may be reliably diagnosed with light microscopy alone.

Inter-Institutional Partnerships to Develop Veterinarian-Investigators through the NIH Comparative Biomedical Scientist Training Program Benefit One Health Goals.

Limitations in workforce size and access to resources remain perennial challenges to greater progress in academic veterinary medicine and engagement between human and veterinary medicine (One Health). Ongoing resource constraints occur in part due to limited public understanding of the role veterinarians play in improving human health. One Health interactions, particularly through interdisciplinary collaborations in biomedical research, present constructive opportunities to inform resource policies and advance health care. To this end, inter-institutional partnerships between individual veterinary medical education programs (VMEPs) and several National Institutes of Health (NIH) intramural research programs have created synergies beyond those provided by individual programs. In the NIH Comparative Biomedical Scientist Training Program (CBSTP), interdisciplinary cross-training of veterinarians consisting of specialty veterinary medicine coupled with training in human disease research leading to a PhD, occurs collaboratively on both VMEP and NIH campuses. Pre-doctoral veterinary student research opportunities have also been made available. Through the CBSTP, NIH investigators and national biomedical science policy makers gain access to veterinary perspective and expertise, while veterinarians obtain additional opportunities for NIH-funded research training. CBSTP Fellows serve as de facto ambassadors enhancing visibility for the profession while in residence at NIH, and subsequently through a variety of university, industry, and government research appointments, as graduates. Thus, the CBSTP represents an inter-institutional opportunity that not only addresses critical needs for veterinarian-scientists in the biomedical workforce, but also simultaneously exposes national policy makers to veterinarian-scientists' specialized training, leading to more effective realization of One Health goals to benefit human and animal health.

Remission after complete excision of an intramedullary hemangioma with an identifiable tumor plane in a dog.

OBJECTIVE: To describe the use of an identifiable tumor plane (ITP) during myelotomy to excise an intramedullary hemangioma in a dog and report the outcome. STUDY DESIGN: Case report. ANIMALS: One 5.5-year-old 42.9-kg spayed female Leonberger dog. METHODS: Clinical signs included progressive proprioceptive deficits of both pelvic limbs. Magnetic resonance imaging was consistent with a dorsal intramedullary mass at L3-L4. A laminectomy of the third and fourth lumbar vertebrae provided access for dorsal myelotomy. A clear surgical ITP was identified between the intramedullary mass and the spinal cord facilitating complete surgical resection. RESULTS: Histopathological examination was consistent with a hemangioma. Postoperative MRI was consistent with complete excision of the mass. No evidence of recurrence was found by MRI at 3 months and at 22 months after surgery. Mild proprioceptive deficits persisted in the right pelvic limb. CONCLUSION: A clear ITP was present, and gross-total resection (GTR) was achieved without significant morbidity. Persistent clinical remission resulted from surgery as the sole therapy. CLINICAL SIGNIFICANCE: For an intramedullary tumor, GTR is the absence of visible tumor on intraoperative inspection combined with the absence of intramedullary contrast enhancement on postoperative MRI. When an ITP is present, GTR and resultant long-term remission may be more likely.

Immunologic and gene expression profiles of spontaneous canine oligodendrogliomas.

Malignant glioma (MG), the most common primary brain tumor in adults, is extremely aggressive and uniformly fatal. Several treatment strategies have shown significant preclinical promise in murine models of glioma; however, none have produced meaningful clinical responses in human patients. We hypothesize that introduction of an additional preclinical animal model better approximating the complexity of human MG, particularly in interactions with host immune responses, will bridge the existing gap between these two stages of testing. Here, we characterize the immunologic landscape and gene expression profiles of spontaneous canine glioma and evaluate its potential for serving as such a translational model. RNA in situ hybridization, flowcytometry, and RNA sequencing were used to evaluate immune cell presence and gene expression in healthy and glioma-bearing canines. Similar to human MGs, canine gliomas demonstrated increased intratumoral immune cell infiltration (CD4+, CD8+ and CD4+Foxp3+ T cells). The peripheral blood of glioma-bearing dogs also contained a relatively greater proportion of CD4+Foxp3+ regulatory T cells and plasmacytoid dendritic cells. Tumors were strongly positive for PD-L1 expression and glioma-bearing animals also possessed a greater proportion of immune cells expressing the immune checkpoint receptors CTLA-4 and PD-1. Analysis of differentially expressed genes in our canine populations revealed several genetic changes paralleling those known to occur in human disease. Naturally occurring canine glioma has many characteristics closely resembling human disease, particularly with respect to genetic dysregulation and host immune responses to tumors, supporting its use as a translational model in the preclinical testing of prospective anti-glioma therapies proven successful in murine studies.

Immunohistochemical Expression of CD31 (PECAM-1) in Nonendothelial Tumors of Dogs.

CD31 immunoreactivity has been reported in human nonendothelial tumors of both epithelial and mesenchymal origin. This study examined CD31 immunoreactivity of 347 formalin-fixed, paraffin-embedded normal, nonneoplastic, and neoplastic canine tissues. CD31 expression was considered positive if at least 10% of the cell population had membranous reactivity. Labeling with the CD31 antibody (clone JC/70A) was observed in 16 samples of normal organs (liver, kidney, lymph node), 6 of 6 specimens of hepatic nodular hyperplasia, 3 of 3 hepatic regenerative nodules, 1 of 4 anal sac carcinomas, 6 of 6 hemangiosarcomas, 18 of 20 hepatocellular carcinomas, 1 of 6 mammary carcinomas, 3 of 5 plasmacytomas, 18 of 53 renal cell carcinomas, and 1 of 5 cutaneous histiocytomas. CD31 expression did not correlate with case outcome in hepatocellular or renal cell carcinomas. Although distinguishing hemangiosarcoma from other neoplasms is typically straightforward, pathologists should be aware of potential cross-reactivity when relying on CD31 immunohistochemistry for diagnosis, particularly in small biopsy samples or when faced with an epithelioid or poorly differentiated vascular neoplasm.

Immunohistochemical Evaluation of Canine Pituitary Adenomas Obtained by Transsphenoidal Hypophysectomy.

Hypophysectomy specimens from 16 dogs with pituitary adenoma were evaluated with periodic acid-Schiff (PAS), reticulin, and immunohistochemistry for adrenocorticotrophic hormone (ACTH), melanocyte stimulating hormone (MSH), growth hormone (GH), and Ki-67. The reticulin network was obliterated in all adenomas. One adenoma expressed ACTH and GH. Eight corticotroph adenomas were basophilic to chromophobic, and PAS- and ACTH-positive. Seven melanotroph adenomas were distinguished from corticotroph adenomas by expression of MSH. Pituitary-dependent hypercortisolism was diagnosed in 5 of 8 dogs with corticotroph and 4 of 7 with melanotroph adenoma. Pituitary height/brain area (P/B) ratio was elevated in all dogs. Previous canine hypophysectomy studies suggested that melanotroph adenomas were larger and carried a worse prognosis than corticotroph adenomas; however, in this study, corticotroph adenomas in comparison to melanotroph adenomas were larger (median P/B ratio: 1.06 versus 0.76), more proliferative (median Ki-67 index: 9.47% versus 1.99%), and associated with shorter survival (median: 300 versus 793 days). Recommended immunohistochemistry for PAS-positive pituitary adenomas includes ACTH and MSH to distinguish corticotrophs from melanotrophs and Ki-67 for proliferation index.

Histopathologic Findings in Canine Pituitary Glands.

To optimize the histologic evaluation of hypophysectomy specimens, sections of 207 canine pituitary glands (196 postmortem, 11 hypophysectomy specimens) were reviewed. Adenohypophyseal proliferation was the most common (n = 79) lesion. Proliferative lesions were sparsely to densely granulated; the granules were usually basophilic to chromophobic and periodic acid-Schiff-positive. Adenohypophyseal proliferation was classified as hyperplasia (n = 40) if ≤2 mm diameter with intact reticulin network, as microadenoma (n = 22) for 1-5 mm homogeneous nodules with lost reticulin network, or as macroadenoma (n = 17) for larger tumors. Craniopharyngeal duct cysts were common incidental lesions and the only lesion in 15 dogs. Uncommon diagnoses included lymphoma (n = 4), hemorrhagic necrosis (n = 4), metastatic carcinoma (n = 3), hypophysitis (n = 3), ependymoma (n = 2), craniopharyngioma (n = 2), and 1 case each of metastatic melanoma, pituicytoma, gliomatosis, germ cell tumor, meningioma, and atrophy. The pituitary histologic diagnosis was associated with hyperadrenocorticism (HAC; P < .001) and adrenocortical histologic diagnosis ( P = .025). Both HAC and adrenocortical hyperplasia showed a positive trend with the degree of adenohypophyseal proliferation. The association of adrenocortical hyperplasia with HAC was not significant ( P = .077). Dogs with adenohypophyseal proliferations were older than dogs with normal pituitary glands ( P < .05). Brachycephalic breeds were overrepresented among dogs with pituitary macroadenoma or craniopharyngeal duct cysts, but the association was not statistically significant ( P = .076). Adenohypophyseal hyperplasia was more common than adenoma among postmortem specimens, but was unexpected in >80% of cases. Pituitary macroadenoma was the most common diagnosis in hypophysectomy specimens.

IMAGING DIAGNOSIS -ANTEMORTEM DETECTION OF OLIGODENDROGLIOMA "CEREBROSPINAL FLUID DROP METASTASES" IN A DOG BY SERIAL MAGNETIC RESONANCE IMAGING.

An English Bulldog underwent radiation therapy of an intracranial, left lateral ventricle mass. Following resolution of the primary mass, an intraventricular fourth ventricle lesion developed. Subsequently, multiple lesions developed from the cervical central canal and leptomeninges. Serial magnetic resonance imaging documented the propagation of lesions along the cerebrospinal fluid (CSF) pathways, known as "CSF drop metastasis." Histopathology confirmed multifocal intraventricular and leptomeningeal oligodendroglioma. Oligodendroglioma should be included in the differential diagnosis for an intraventricular tumor exhibiting apparent CSF drop metastasis.

Surfactant Protein A and Napsin A in the Immunohistochemical Characterization of Canine Pulmonary Carcinomas: Comparison With Thyroid Transcription Factor-1.

Thyroid transcription factor-1 (TTF-1) is a specific and sensitive marker for canine pulmonary tumors but is also expressed in thyroid carcinomas, which commonly metastasize to lung. Napsin A and surfactant protein A (SP-A) are used in the histologic diagnosis of non-small-cell lung cancer in humans but have not been thoroughly evaluated in neoplasms of dogs. The objective of this study was to compare the efficacy of immunohistochemistry for SP-A, napsin A, and TTF-1 in the diagnosis of canine pulmonary carcinomas. TTF-1, napsin A, and SP-A antibodies were applied to 67 formalin-fixed, paraffin-embedded canine pulmonary tumors. Although each marker had good sensitivity, only 3% (2/67) of lung tumors were negative for SP-A compared with 7% (5/67) and 9% (6/67) for napsin A and TTF-1, respectively. Each antigen was detected in a greater percentage of cells of tumors with acinar or papillary patterns compared with those with squamous differentiation. SP-A immunoreactivity was absent in all 113 nonpulmonary tumors tested. Of 108 normal tissues, SP-A was detected only in lung and in 1 of 6 adrenal, 1 of 3 endometrial, and 1 of 4 hepatic sections. Based on these findings, SP-A and napsin A are useful markers of canine lung epithelial neoplasia. Of these, SP-A is the most sensitive and specific (a possible pitfall is the need to distinguish entrapped normal pulmonary epithelial cells or alveolar macrophages from neoplastic cells) and can be used in combination with TTF-1 or napsin A to improve detection and differentiation of pulmonary carcinomas from metastatic tumors in the canine lung.

Pax8, Napsin A, and CD10 as Immunohistochemical Markers of Canine Renal Cell Carcinoma.

Pax8, napsin A, and CD10 are useful immunohistochemical markers of human renal cell carcinoma (RCC); however, their diagnostic utility in canine RCC is unclear. Forty formalin-fixed paraffin-embedded renal cell carcinomas from dogs (15 papillary, 12 solid, and 13 tubular) and 10 metastases were evaluated for expression of Pax8, napsin A, and CD10. Thirty-nine (98%), 24 (60%), and 19 (50%) tumors expressed Pax8 (nuclear labeling), napsin A (cytoplasmic labeling), and CD10 (cytoplasmic and membranous labeling), respectively. Pax8 was expressed in 92% of solid, 100% of papillary, and 100% of tubular tumors. Napsin A was expressed in 58% of solid, 60% of papillary, and 62% of tubular RCC. CD10 was expressed in 33% of solid, 47% of papillary, and 62% of tubular RCC. Pax8 was expressed in 80% of the metastatic tumors, napsin A in 60%, and CD10 in 50%. Additionally, Pax8 immunoreactivity was stronger overall than that of napsin A or CD10. In summary, Pax8 is a more sensitive marker than napsin A or CD10 for primary and metastatic canine RCC; its nuclear and more intense reactivity also makes it easier to interpret. Tubular and papillary RCCs were more likely than solid RCC to express all 3 markers. These findings highlight the utility of Pax8 as an immunohistochemical marker in diagnosing all major subtypes of canine primary and metastatic renal cell carcinoma.

IMAGING DIAGNOSIS-NUCLEAR SCINTIGRAPHIC, RADIOLOGICAL, AND PATHOLOGIC CHARACTERISTICS OF METASTATIC PILOMATRICOMA IN A DOG.

A 6-year-old castrated Goldendoodle dog was presented for left-sided lameness of 3 weeks' duration. Focal, moderate to marked increased 99m Tc-methylene diphosphonate (99m Tc-MDP) uptake was detected in the right caudal lung lobe, caudal angle of the left scapula, and the distal aspect of the left femur with whole body bone phase scintigraphy. Radiographs identified a well-circumscribed, oval-shaped soft tissue opaque mass in the right caudal lung lobe; a suspect oval-shaped osteolytic lesion in the proximal third of the left scapula; and an osteolytic lesion in the distal aspect of the left femur. Metastatic pilomatricoma was confirmed histologically at all three sites.

PREVALENCE AND SIGNIFICANCE OF AN ULTRASONOGRAPHIC COLONIC MUSCULARIS HYPERECHOIC BAND PARALLELING THE SEROSAL LAYER IN DOGS.

The muscularis layer of the canine colon has been reported to appear homogeneously hypoechoic on ultrasonography. A hyperechoic band in the muscularis layer paralleling the serosal surface has been observed by authors in routine canine abdominal ultrasound examinations. The purpose of this prospective and retrospective cross-sectional study was to determine the prevalence of this lesion, characterize its ultrasonographic and postmortem histologic features, and correlate its presence with clinical signs of gastrointestinal disease. In the prospective study, all dogs that underwent routine abdominal ultrasonography by one of two observers during a 4-week period were included without any exclusion criteria. One observer reviewed ultrasound images and recorded the presence or absence of this lesion and its distribution, e.g. focal (< 2 cm long) or diffuse (> 2 cm long). In the retrospective study, all dogs that had both abdominal ultrasonography and necropsy from January 2011 to December 2013 were included without any exclusion criteria. Histologic examinations were performed by two observers and Masson's trichrome stain was used to identify fibrous collagen. Prevalence for the hyperechoic band was 32% in the prospective and 4.8% in the retrospective sample populations, respectively. The hyperechoic band appeared as diffuse, focal, or a combination of both. Histologic sections were available for six dogs. In a few cases, the lesion corresponded to the presence of fibrous tissue in the myenteric plexus or in the tunica muscularis. None of the dogs had a history of diarrhea. Findings supported the hypothesis that a colonic muscularis hyperechoic band paralleling the serosal layer in dogs could be a normal variant rather than a marker of disease.

Cytologic features of canine melanotroph and corticotroph pituitary adenomas.

BACKGROUND: The introduction of intraoperative cytology revolutionized neurosurgical procedures in human medicine, providing real-time diagnostic guidance to surgeons and contributing to improved patient outcomes. In the realm of veterinary medicine, the understanding of pituitary tumors in dogs and cats remains limited due to challenges in obtaining antemortem samples of central nervous system lesions. OBJECTIVES: The aim of this study was to describe the cytologic features of pituitary adenomas in 12 dogs that underwent hypophysectomy. METHODS: The series included nine melanotroph adenomas and three corticotroph adenomas. Definitive diagnosis was based on histopathology and immunohistochemistry. RESULTS: Cytologically, the adenomas had high numbers of bare nuclei and intact cells that were round to polygonal and situated individually or in small clusters. The intact cells had round to oval, eccentric nuclei with finely stippled chromatin and one to three prominent nucleoli and ample to abundant lightly basophilic to amphophilic, grainy cytoplasm with distinct borders, and variable numbers of discrete vacuoles. Mild-to-moderate anisocytosis and anisokaryosis, occasional binucleation, rare and atypical mitotic figures, and nuclear molding were also observed. CONCLUSIONS: The results suggest that intraoperative cytology of canine pituitary adenomas holds promise as a valuable diagnostic tool, aiding swift differentiation from other sellar masses before histologic confirmation. Cytologic characterization of pituitary adenomas in dogs is exceptionally rare in the scientific literature, making this study one of the first to offer a comprehensive description of these cytologic features.

Effect of anisotropy and spatial compound imaging on renal cortical echogenicity in dogs.

The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspected to have renal dysfunction. Focal increases in echogenicity have been attributed to neoplasia, infection, calcification, fibrosis, gas, and infarction. Anisotropic backscatter has been described as a source of focally increased renal cortical echogenicity in several species. The source of anisotropy appears to be the medullary rays, which are oriented perpendicular to the renal capsule. Spatial compound imaging (SCI) is an ultrasound setting that uses beam steering to acquire and average several overlapping scans of an object from different view angles, creating a compound image that is updated in real time. The impact of insonation angle and SCI on renal cortical echogenicity was evaluated ex vivo in eight kidneys from four dogs. Significant angle-dependent differences in cortical echogenicity were detected with both microconvex and linear transducers (P < 0.0001). Furthermore, the angle-dependent echogenicity differences persisted when SCI mode was used. Our finding that echogenicity was increased using a perpendicular insonation angle (90°) relative to the tubules, compared to a parallel insonation angle (0°) should assist in the interpretation of ultrasonographic images of the dog kidney.

Establishment and characterization of two novel patient-derived lines from canine high-grade glioma.

High-grade glioma is an aggressive cancer that occurs naturally in pet dogs. Canine high-grade glioma (cHGG) is treated with radiation, chemotherapy or surgery, but has no curative treatment. Within the past eight years, there have been advances in our imaging and histopathology standards as well as genetic charactereization of cHGG. However, there are only three cHGG cell lines publicly available, all of which were derived from astrocytoma and established using methods involving expansion of tumour cells in vitro on plastic dishes. In order to provide more clinically relevant cell lines for studying cHGG in vitro, the goal of this study was to establish cHGG patient-derived lines, whereby cancer cells are expanded in vivo by injecting cells into immunocompromized laboratory mice. The cells are then harvested from mice and used for in vitro studies. This method is the standard in the human field and has been shown to minimize the acquisition of genetic alterations and gene expression changes from the original tumour. Through a multi-institutional collaboration, we describe our methods for establishing two novel cHGG patient-derived lines, Boo-HA and Mo-HO, from a high-grade astrocytoma and a high-grade oligodendroglioma, respectively. We compare our novel lines to G06-A, J3T-Bg, and SDT-3G (traditional cHGG cell lines) in terms of proliferation and sensitivity to radiation. We also perform whole genome sequencing and identify an NF1 truncating mutation in Mo-HO. We report the characterization and availability of these novel patient-derived lines for use by the veterinary community.

Drug combinations identified by high-throughput screening promote cell cycle transition and upregulate Smad pathways in myeloma.

Drug resistance and disease progression are common in multiple myeloma (MM) patients, underscoring the need for new therapeutic combinations. A high-throughput drug screen in 47 MM cell lines and in silico Huber robust regression analysis of drug responses revealed 43 potentially synergistic combinations. We hypothesized that effective combinations would reduce MYC expression and enhance p16 activity. Six combinations cooperatively reduced MYC protein, frequently over-expressed in MM and also cooperatively increased p16 expression, frequently downregulated in MM. Synergistic reductions in viability were observed with top combinations in proteasome inhibitor-resistant and sensitive MM cell lines, while sparing fibroblasts. Three combinations significantly prolonged survival in a transplantable Ras-driven allograft model of advanced MM closely recapitulating high-risk/refractory myeloma in humans and reduced viability of ex vivo treated patient cells. Common genetic pathways similarly downregulated by these combinations promoted cell cycle transition, whereas pathways most upregulated were involved in TGFß/SMAD signaling. These preclinical data identify potentially useful drug combinations for evaluation in drug-resistant MM and reveal potential mechanisms of combined drug sensitivity.