The Importance of Ultrasonography in the Evaluation of Mammary Tumors in Bitches

The high incidence of mammary tumors in small animals is concerning. Patient history, clinical examination, physical evaluation, and imaging studies are important for clinical staging. Ultrasonography is commonly applied to investigate the presence of abdominal metastasis. However, it has been shown to provide important information regarding mammary tumors' architecture and advanced sonographic techniques can provide information regarding neovascularization, stiffness, and perfusion. Different techniques have been investigated to determine accuracy to predict the lesions' histological classification. This paper reviews the information regarding each sonographic technique in the evaluation of mammary tumors, describing the most common findings and their potential to accurately assess and predict malignancy. Even though the gold standard for the diagnosis of mammary lesions is the histopathological examination, some ultrasonographic features described can predict the potential of a lesion being malignant. Among the different sonographic techniques, elastography can be considered the most reliable modality to accurately differentiate benign from malignant tumors when malignant lesions present increased stiffness. However, the combination of all sonographic techniques can provide important information that can lead to a better therapeutic approach and clinical staging. Furthermore, the potential of the sonographic study, especially CEUS to monitor therapeutic progression, demonstrate the need of further studies.

Difference in cytological findings of healthy and conjunctivitis/keratoconjunctivitis affected canine eyes between variably experienced evaluators

Background and Aim: Cytology investigations are a frequent part of ophthalmological examination. We aimed to assess whether the cytological findings of healthy and conjunctivitis/keratoconjunctivitis samples differed based on the evaluator's experience. Materials and Methods: A study evaluated healthy eyes (n = 40) and eyes affected with keratoconjunctivitis and/ or conjunctivitis (n = 28) in dogs. An ophthalmological examination was performed before sampling the eyes using a sterile cotton swab. An evaluator with theoretical experience and one with undergone clinical pathology residency training performed cytology blinded to the clinical findings. Results: In the healthy eyes group, the agreement between the evaluators for cellularity was nonexistent, while that for cell preservation and mucus content was fair. In the affected eyes group, the agreement for cellularity and mucus content was moderate, while that for cell preservation was fair. The inadequate sample rate differed significantly between the two evaluators in the healthy eyes group (p = 0.006) but not in the affected eyes group (p = 0.083). Bacterial presence was detected by both evaluators, and the findings did not differ statistically from the bacteriology results (p = 0.05). Significant variations were noted in the differential cell count; the mean count of the superficial epithelial cells and goblet cells of the healthy eyes group (p < 0.05) and that of the basal/intermediate cells and neutrophils of the affected eyes (p < 0.05) showed significant differences. Conclusion: The evaluator's experience significantly affected the differential cell count in both the healthy and affected eyes groups. Neutrophil degeneration was not observed by the less experienced evaluator, whereas bacteria were detected equally well by both the evaluators.

Review of Histological Grading Systems in Veterinary Medicine

Tumor grading is a method to quantify the putative clinical aggressiveness of a neoplasm based on specific histological features. A good grading system should be simple, easy to use, reproducible, and accurately segregate tumors into those with low versus high risk. The aim of this review is to summarize the histological and, when available, cytological grading systems applied in veterinary pathology, providing information regarding their prognostic impact, reproducibility, usefulness, and shortcomings. Most of the grading schemes used in veterinary medicine are developed for common tumor entities. Grading systems exist for soft tissue sarcoma, osteosarcoma, multilobular tumor of bone, mast cell tumor, lymphoma, mammary carcinoma, pulmonary carcinoma, urothelial carcinoma, renal cell carcinoma, prostatic carcinoma, and central nervous system tumors. The prognostic relevance of many grading schemes has been demonstrated, but for some tumor types the usefulness of grading remains controversial. Furthermore, validation studies are available only for a minority of the grading systems. Contrasting data on the prognostic power of some grading systems, lack of detailed instructions in the materials and methods in some studies, and lack of data on reproducibility and validation studies are discussed for the relevant grading systems. Awareness of the limitations of grading is necessary for pathologists and oncologists to use these systems appropriately and to drive initiatives for their improvement.

Myoepithelial cells and extracellular matrix in the cytologic differentiation of canine mammary tumors

BACKGROUND

Mammary neoplasms are common tumors in intact female dogs. Fine-needle aspiration cytology (FNAC) is a valuable diagnostic tool and has gained some credibility in the diagnosis of mammary tumors in dogs. Prompt classification of canine mammary tumors using cytology would enhance feasibility as a prognostic tool and guide clinical and surgical management.

OBJECTIVES

We aimed to examine background elements to differentiate mammary tumors using FNAC. We proposed to distinguish simple from complex and mixed tumors by identifying myoepithelial (ME) cells and different types of extracellular matrix. Additionally, we determined the accuracy of FNAC to differentiate benign from malignant tumors.

METHODS

One hundred and one mammary tumors from female dogs were included in this study. We compared FNAC using histopathology as the gold standard. Cellular and background components were evaluated and identified. The cytologic accuracy, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) for diagnosing malignancy were determined, excluding inadequate samples.

RESULTS

The cytologic-histologic agreement was 92.5% for simple carcinomas, 57.9% for complex-type carcinomas, 57.1% for mixed-type carcinomas, 27.3% for carcinosarcomas, and 100% for osteosarcomas. Myoepithelial cells were successfully identified using FNAC. Myxoid and chondroid/osteoid matrix were satisfactorily recognized. Cytologic accuracy, Se, Sp, PPV, and NPV for diagnosing malignancy were 99%, 100%, 83%, 99%, and 100%, respectively.

CONCLUSIONS

Chondroid/osteoid matrix was noted in mixed tumors but not in complex tumors. Myxoid matrix, often associated with ME cells, was noted in complex and mixed tumors. Mesenchymal cells were differentiated from ME cells, allowing the distinction of simple carcinomas with scirrhous reaction from complex and mixed tumors.

Microtomographic characterization of calcifications in canine mammary tumours

The present work describes the microtomographic characterization of macro- and microcalcifications present in excised canine mammary glands. In human breast cancer, microcalcifications are highly relevant for diagnosis and prognosis, often being the sole element determining biopsy. Canine mammary tumours are considered a model for human breast cancer, but the morphological features of calcifications had still to be studied in this species. The objective of this research is to contribute to the characterization of the mineralization features of the canine mammary gland. In the present study, the excised mammary glands of 33 bitches underwent fluoroscopic examination. In 30 of the samples, the presence of calcification was suspected, and multiple biopsies were taken of these areas. Biopsy fragments underwent microtomographic scanning. Microcalcifications were found in non-neoplastic glandular tissue, benign and malign lesions, as it is known to happen in humans. Qualitative evaluation regarding morphology of the imaged calcifications showed similarities to breast cancer findings, based on the BI-RADS 2013 classification, such as pleomorphism and shape. No differences in the quantitative morphological parameters of volume, surface, surface/volume, SMI and structure thickness were found when macrocalcifications were considered. However, although significant differences existed in these parameters between microcalcifications from malignant canine mammary tumours and the two other groups, none were found between non-neoplastic and benign tumours. Findings further support the use of this spontaneous animal model for the study of human breast cancer, considering how clinically relevant microcalcifications are in humans.

Cytological Grading of Breast Tumors-The Human and Canine Perspective

Human breast cancers (HBCs) are one of the leading causes of global cancer death among women. Domesticated canines are the most affected domestic species with a prevalence rate of breast cancer more than three times in women. While the human cancer patients receive substantial diagnostic and treatment facilities, inadequacy in canine cancer care, calls for greater attention. Fine Needle Aspiration Cytology (FNAC) is comparatively simple, quick, and easily reproducible technique, which aids in pre-surgical diagnosis. In humans, FNAC has a standard protocol, the Robinson's grading system, which has high correlation with the established histological grading system of Scarff Bloom- Richardson. However, Canine Mammary Tumors (CMTs), which are known to be similar to HBCs in biological behavior and gene expressions, still bank on the histopathological methods for diagnostic purposes. This review sheds light on various factors that could be considered for developing a standard FNAC technique for CMT grading and analyzes its future perspectives.

Diagnostic efficacy of smear cytology and Robinson's cytological grading of canine mammary tumors with respect to histopathology, cytomorphometry, metastases and overall survival

Cytology is a simple, rapid, and inexpensive method used for pre-operative diagnosis of canine mammary tumors (CMTs) in veterinary practice. Studies related to human breast cancer showed the Robinson’s grading system—established for invasive ductal carcinoma, not otherwise specified (IDC, NOS) and used on cytological material—to not only closely correspond to the histopathological grading but also be helpful in assessing prognosis and selecting most suitable treatments before surgery. The objectives of this study were: to evaluate the accuracy of cytological diagnosis and cytological Robinson’s grading system compared to the histopathological examination of CMTs; to compare of cytological features and cytomorphometric parameters with tumor behavior, as well as cytological and histological grading; and to determine an association of the Robinson’s grading system and cytological background details with metastases, and patients’ survival. We report substantial diagnostic accuracy in detecting simple types and high grade tumors. Cytological diagnosis of tumor behavior showed relatively low sensitivity and specificity compared to human studies, and this might be caused by the heterogeneous morphology of CMTs. The presence of mucosecretory material and extracellular matrix was not significantly associated with tumor behavior. We report a positive correlation between both grading systems and cytological features (included in Robinson’s grading), the presence of necrotic debris, inflammation, and red blood cells. A negative correlation was determined only for the presence of extracellular matrix. The univariate and multivariate analyses confirmed a significantly higher risk of developing metastasis and shorter overall survival for dogs with tumors of grade 2 or 3 on cytology. In addition, these tumors were the most common cause of CMT-related deaths in dogs. Taken together, our findings suggest that the Robinson’s method of cytological grading applied for malignant CMTs evaluated in cytological smears regardless of tumor type can be adapted to veterinary cytology. Additionally, some background features seem to aid malignancy assessment.