Ombretta Capitani

Use of histologic margin evaluation to predict recurrence of cutaneous malignant tumors in dogs and cats after surgical excision.

OBJECTIVE To assess the usefulness of histologic evaluation of surgical margins to predict local recurrence of cutaneous malignant tumors in dogs and cats treated by means of surgical excision. DESIGN Prospective case series. ANIMALS 40 dogs and 20 cats. PROCEDURES 60 surgically excised tumors (20 soft tissue sarcomas [STSs], 20 mast cell tumors [MCTs], and 20 carcinomas) were examined histologically. Margins were classified as clean, close, or infiltrated; histologic grade was assessed in STSs and MCTs. Recurrence rates and recurrence-free intervals (RFIs) during a 24-month follow-up period were recorded, and method accuracy was calculated. RESULTS Surgical margins were clean in 29 of 60 (48%) tumors, close in 11 (18%), and infiltrated in 20 (33%). Tumors recurred in 27 of 60 (45%) animals, with a mean ± SD RFI of 229 ± 173 days. Recurrence rates for animals that had tumors with infiltrated (16/20) or close (8/11) margins were significantly higher than recurrence rate for animals that had tumors with clean margins (3/29). Margin classification was a significant predictor of RFI. Accuracy of the method to predict recurrence was 94% for carcinomas, 87% for STSs, and 76% for MCTs. CONCLUSIONS AND CLINICAL RELEVANCE Histologic assessment of margin status was useful for predicting local recurrence of cutaneous malignant tumors in dogs and cats treated by means of excision alone. Method accuracy varied among tumor types and grades. Recurrence times suggested postsurgical follow-up should continue for ≥ 2 years. Results were similar for animals with infiltrated and close tumor margins, and careful postsurgical management is recommended for both.

Restored perfusion and reduced inflammation in the infarcted heart after grafting stem cells with a hyaluronan-based scaffold

The aim of this study is to investigate the blood perfusion and the inflammatory response of the myocardial infarct area after transplanting a hyaluronan‐based scaffold (HYAFF®11) with bone marrow mesenchymal stem cells (MSCs). Nine‐week‐old female pigs were subjected to a permanent left anterior descending coronary artery ligation for 4 weeks. According to the kind of the graft, the swine subjected to myocardial infarction were divided into the HYAFF®11, MSCs, HYAFF®11/MSCs and untreated groups. The animals were killed 8 weeks after coronary ligation. Scar perfusion, evaluated by Contrast Enhanced Ultrasound echography, was doubled in the HYAFF®11/MSCs group and was comparable with the perfusion of the healthy, non‐infarcted hearts. The inflammation score of the MSCs and HYAFF®11/MSCs groups was near null, revealing the role of the grafted MSCs in attenuating the cell infiltration, but not the foreign reaction strictly localized around the fibres of the scaffold. Apart from the inflammatory response, the native tissue positively interacted with the HYAFF®11/MSCs construct modifying the extracellular matrix with a reduced presence of collagene and increased amount of proteoglycans. The border‐zone cardiomyocytes also reacted favourably to the graft as a lower degree of cellular damage was found. This study demonstrates that the transplantation in the myocardial infarct area of autologous MSCs supported by a hyaluronan‐based scaffold restores blood perfusion and almost completely abolishes the inflammatory process following an infarction. These beneficial effects are superior to those obtained after grafting only the scaffold or MSCs, suggesting that a synergic action was achieved using the cell‐integrated polymer construct.

Epidermal growth factor receptor expression is predictive of poor prognosis in feline cutaneous squamous cell carcinoma

The aim of this study was to investigate epidermal growth factor receptor (EGFR) expression in feline cutaneous squamous cell carcinoma (FC-SCC) and assess its prognostic role. Nineteen formalin-fixed paraffin-embedded excisional biopsies of FC-SCC were tested for EGFR expression using immunohistochemistry (IHC). Relationships between EGFR expression and histopathological parameters (differentiation, mitotic activity), disease-free interval (DFI) and overall survival (OS) at 24 months were further investigated. Fourteen of 19 tumours (73.7%) were positive for EGFR, with great variation in intensity and proportion of labelled cells. EGFR expression was not correlated with tumour differentiation or mitotic activity. Nine cats (47.4%) died of tumour-related causes. Patients with EGFR-positive tumours had a significantly worse outcome (P=0.0217), with decreased DFIs (P=0.0075) and survival times (P=0.0391). These data suggest that EGFR expression carries a negative prognostic significance in FC-SCC. EGFR inhibitors in association with conventional treatments may improve outcome for the subgroup of cats with EGFR-positive tumours.

Comparison between Culture Conditions Improving Growth and Differentiation of Blood and Bone Marrow Cells Committed to the Endothelial Cell Lineage.

The aim of this study was to compare different cell sources and culture conditions to obtain endothelial progenitor cells (EPCs) with predictable antigen pattern, proliferation potential and in vitro vasculogenesis. Pig mononuclear cells were isolated from blood (PBMCs) and bone marrow (BMMCs). Mesenchymal stem cells (MSCs) were also derived from pig bone marrow. Cells were cultured on fibronectin in the presence of a high concentration of VEGF and low IGF-1 and FGF-2 levels, or on gelatin with a lower amount of VEGF and higher IGF-1 and FGF-2 concentrations. Endothelial commitment was relieved in almost all PBMCs and BMMCs irrespective of the protocol used, whilst MSCs did not express a reliable pattern of EPC markers under these conditions. BMMCs were more prone to expand on gelatin and showed a better viability than PBMCs. Moreover, about 90% of the BMMCs pre-cultured on gelatin could adhere to a hyaluronan-based scaffold and proliferate on it up to 3 days. Pre-treatment of BMMCs on fibronectin generated well-shaped tubular structures on Matrigel, whilst BMMCs exposed to the gelatin culture condition were less prone to form vessel-like structures. MSCs formed rough tubule-like structures, irrespective of the differentiating condition used. In a relative short time, pig BMMCs could be expanded on gelatin better than PBMCs, in the presence of a low amount of VEGF. BMMCs could better specialize for capillary formation in the presence of fibronectin and an elevated concentration of VEGF, whilst pig MSCs anyway showed a limited capability to differentiate into the endothelial cell lineage.

Prognostic significance of Kit receptor tyrosine kinase dysregulations in feline cutaneous mast cell tumors.

Feline cutaneous mast cell tumors (FeCMCTs) are characterized by variable biological behavior. Development of multiple nodules and potential visceral involvement, along with inconsistency of conventional prognostic aids, justify uncertainty in differentiating benign from malignant forms. c-Kit proto-oncogene activating mutations have been reported in feline mast cell tumors (MCTs), but their prognostic relevance was not investigated. This study was performed on FeCMCTs with variable clinical outcome to assess whether Kit cytoplasmic immunohistochemical labeling can be regarded as indicative of c-Kit mutations and to evaluate the relationship between Kit dysregulation and survival. Twenty-four cats diagnosed with a primary cutaneous MCT were enrolled. Kit immunohistochemical pattern and c-Kit (exons 8, 9, 11) mutational status were assessed in 34 tumor samples. Risk factors affecting survival were a number of mitoses greater than 5 per 10 HPFs (P = .017) and cytoplasmic Kit labeling (P = .045). Increased mitotic activity was associated with Kit cytoplasmic expression (P = .01). c-Kit encoding mutations were present in 19 (56%) tumors (exon 8, 19%; exon 9, 71%; exon 11, 10%), however, they were not significantly related to protein expression and they had no influence on prognosis. Additionally, in 6 of 9 (67%) cats, multiple nodules from the same cat had different mutational statuses. Mutations in the fifth immunoglobulin-like domain of Kit occur frequently in FeCMCT, but they are variably associated with aberrant protein expression and do not appear to be strictly correlated with biological behavior. These findings need to be confirmed in larger series, and exploration of further genomic regions of c-Kit is warranted.

Whole body computed tomographic characteristics of skeletal and cardiac muscular metastatic neoplasia in dogs and cats

Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT-guided tru-cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty-one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well-demarcated, oval-to-round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.

CNS and lung metastasis of sebaceous epithelioma in a dog

Sebaceous epithelioma is a common canine cutaneous neoplasm characterized by a preponderance of basaloid cells with few well-differentiated sebocytes. It is considered a low-grade malignancy, as it may occasionally recur at the excision site; the possibility of lymph node metastasis is anecdotally reported, and distant metastases have never been observed. This case report presents the clinical and pathological features of a sebaceous epithelioma of the upper lip with a highly aggressive behaviour. The patient was a 9-year-old female dachshund that developed local recurrence 11 months after the excision of the primary sebaceous epithelioma and multiple lung and central nervous system metastases 5 months later. The designation epitheliomatous sebaceous carcinoma has been suggested for aggressive sebaceous epitheliomas, although differential criteria are still to be determined.

Comparative Assessment of the Accuracy of Cytological and Histologic Biopsies in the Diagnosis of Canine Bone Lesions

Background Osteosarcoma (OSA) should be differentiated from other less frequent primary bone neoplasms, metastatic disease, and tumor‐like lesions, as treatment and prognosis can vary accordingly. Hence, a preoperative histologic diagnosis is generally preferred. This requires collection of multiple biopsies under general anesthesia, with possible complications, including pathological fractures. Fine‐needle aspiration cytology would allow an earlier diagnosis with a significant reduction of discomfort and morbidity. Hypothesis/Objectives The aim of this study was to compare the accuracy of cytological and histologic biopsies in the diagnosis of canine osteodestructive lesions. Animals Sixty‐eight dogs with bone lesions. Methods Retrospective study. Accuracy was assessed by comparing the former diagnosis with the final histologic diagnosis on surgical or post‐mortem samples or, in the case of non‐neoplastic lesions, with follow‐up information. Results The study included 50 primary malignant bone tumors (40 OSAs, 5 chondrosarcomas, 2 fibrosarcomas, and 3 poorly differentiated sarcomas), 6 carcinoma metastases, and 12 non‐neoplastic lesions. Accuracy was 83% for cytology (sensitivity, 83.3%; specificity, 80%) and 82.1% for histology (sensitivity, 72.2%; specificity, 100%). Tumor type was correctly identified cytologically and histologically in 50 and 55.5% of cases, respectively. Conclusions and Clinical Importance The accuracy of cytology was similar to histology, even in the determination of tumor type. In no case was a benign lesion diagnosed as malignant on cytology. This is the most important error to prevent, as treatment for malignant bone tumors includes aggressive surgery. Being a reliable diagnostic method, cytology should be further considered to aid decisions in the preoperative setting of canine bone lesions.

Evaluation of mean echogenicity of tendons and ligaments of the metacarpal region in neonatal foals: A preliminary study.

The aims of this research were to evaluate mean echogenicity (ME) of the deep and superficial digital flexor tendons (DDFT and SDFT), the interosseous muscle (IM), and the accessory ligament of the deep digital flexor tendon (ALDDFT) of the metacarpal region in neonatal foals, and determine the effect of sex, side and body weight on this quantitative ultrasonographic evaluation. Thirteen orthopedically sound neonatal foals were examined. Four areas of study (1A, 1B, 2A, 2B) were identified. Transverse scans of the DDFT, SDFT, IM and ALDDFT were obtained, recorded, and analyzed. The most echogenic structures were the ALDDFT and DDFT, while the SDFT was significantly less echogenic than all other structures (P<0.05). No influence of sex, forelimb, or body weight was observed. The echogenicity of the tenodesmic structures of foals partially overlapped that reported in the metacarpal region in adult horses, except for IM.

Comparison between May-Grünwald-Giemsa and rapid cytological stains in fine-needle aspirates of canine mast cell tumour: Diagnostic and prognostic implications

Mast cell tumours (MCTs) are often diagnosed by cytology based on the identification of purple intracytoplasmic granules with methanolic Romanowsky stains, including May-Grünwald-Giemsa (MGG). In clinical practice, aqueous rapid stains (RS) are commonly used, but mast cell granules may not stain properly. Aim of this prospective study was to investigate the frequency of MCT hypogranularity with RS and its potential implications in tumour identification, cytological grading assessment and recognition of nodal metastatic disease. Cytological preparations of canine primary MCTs and metastatic lymph nodes with subsequent histopathological confirmation were included. For each case, good-quality smears were stained with both MGG and RS and comparatively assessed. Eleven of 60 (18.3%) primary MCTs were hypogranular with RS; 9 of them were histologically high-grade tumours and in 3 cases (5%) a definitive MCT diagnosis could not be made. Accuracy in cytological grading assessment (85%) did not differ between RS and MGG. Thirteen of 28 (46.4%) metastatic lymph nodes were hypogranular with RS and 3 independent observers failed to identify nodal MCT metastases in 7% to 18% of RS-stained smears. This study confirms that, in limited cases, RS can be ineffective in staining MCT granules, particularly in high-grade tumours, thus making diagnosis more dependent on experience and quality of preparations. In dubious cases, methanolic stains should be applied. The use of RS is discouraged for the search of nodal metastases, as the identification of isolated mast cells can be more challenging.