Palliative radiotherapy as treatment for non-resectable soft tissue sarcomas in the dog – a report of 15 cases

Fifteen dogs with various non‐resectable soft tissue sarcomas were treated with a palliative protocol of Cobalt⁶⁰ radiation. Twelve (80%) of the 15 tumours were fibrosarcomas and haemangiopericytomas. Total tumour radiation dose was 24 Gy, given in three 8 Gy fractions, on days 0, 7, 21 or weekly. Thirteen tumours (87%) responded with stable disease; median time to progression and median survival time were 263 and 332 days, respectively. Radiation toxicity was negligible. The survival and local control with this palliative protocol are almost comparable with curative intent primary radiotherapy.     

Intra-operative cisplatin for the treatment of canine extremity soft tissue sarcomas

Nineteen dogs with histologically confirmed soft tissue sarcomas of the extremities were treated with a combination of marginal surgery and intra-operative chemotherapy in the form of cisplatin in a biodegradable implant delivery system (Atrigel^®; Atrix Laboratories, Fort Collins, Co, USA). None of the dogs had evidence of metastasis at time of treatment. The median dose of cisplatin was 52.1 mg/m² (mean 55.4 mg/m², range 18.5–108.6 mg/m²). Wound complications were noted in 16 dogs (84.2%). Median follow-up time was 874 days (mean 777 days, range 125–1463 days). Nine dogs (47.3%) were alive at the time of analysis. Local recurrence occurred in three dogs (16.6%). The time to recurrence was 214, 264 and 874 days.     

Nuclear morphometry in cytological specimens of canine ceruminous adenomas and carcinomas

Stained cytological specimens from eight canine ceruminous adenomas and eight canine ceruminous carcinomas were analysed by computer‐assisted nuclear morphometry. Three carcinomas had metastases in regional lymph nodes at the time of the diagnosis. The morphometric parameters evaluated in this study were mean nuclear area (MNA, µm²), mean nuclear perimeter (MNP, µm), mean nuclear diameter (D mean, µm), minimum nuclear diameter (D min, µm) and maximum nuclear diameter (D max, µm). The study aimed to evaluate (1) the possibility of using nuclear cytomorphometry as an auxiliary diagnostic method to differentiate between canine ceruminous adenomas and adenocarcinomas, and (2) the prognostic value of nuclear morphometry in canine ceruminous carcinomas. The results indicated that (1) MNA, MNP, D mean, D min and D max could be used as effective auxiliary tools for differential diagnosis between canine ceruminous adenomas and adenocarcinomas, and (2) MNA, MNP, D mean and D max are reliable prognostic indicators for canine ceruminous adenocarcinomas.     

Ultrasonographic characteristics of soft tissue tumours in dogs

Objective   To identify and describe the ultrasonographic features of soft tissue tumours in dogs.
Procedure   Superficial soft tissue tumours of various histological types, including mast cell tumours (MCTs) and soft tissue sarcomas (STSs), were evaluated. Ultrasound was used to visualise internal characteristics of the tumour, including vascularity. Tumours were categorised according to size, shape, margin definition, tissue plane mobility, echogenicity, echotexture, acoustic shadowing or enhancement and vessel distribution. Objective measurements of intratumoural blood flow included velocities and maximal perfused cross-sectional area (fractional area). Logistic regression models incorporating a variety of data were used in an attempt to predict the histopathological type of tumours.
Results   The logistic regression model defined by the parameters echotexture, margin definition and presence of subcapsular vessels was highly predictive of MCTs (> 73%; P = 0.024). Several other trends, including a larger size for STSs and less vascularity for both MCTs and STSs, were observed, but did not reach statistical significance.
Conclusion   This preliminary study has shown the potential diagnostic value of ultrasound in differentiating soft tissue tumours. However, at present, ultrasound cannot replace biopsy and histopathological evaluation for tumour diagnosis.     

Cytological grading of canine cutaneous mast cell tumours

A cytological grading for mast cell tumours (MCTs) would be highly desirable, allowing to select the most appropriate therapeutic intervention prior to surgery. This study evaluates the applicability on fine‐needle aspirations (FNAs) of the novel Kiupel grading system, based on number of mitoses, multinucleated cells, bizarre nuclei and presence of karyomegaly. Fifty consecutive cases with pre‐operative cytological diagnosis were included. In cytological specimens, approximately 1000 cells were evaluated, and the histological grade was assessed on the corresponding resected specimens. On cytology, the above parameters were significantly different between histologically low‐grade and high‐grade tumours (P < 0.001). The cytograding correctly predicted the histological grade in 47 cases (accuracy, 94%; sensitivity, 84.6%; specificity, 97.3%). Two high‐grade MCTs (4%) were not detected on cytology. The cytograding can provide helpful insights to assist clinical decisions in most cases. However, the risk of underestimation in a minority of patients represents a limit to the overall utility of the technique.     

Detection of comorbidities and synchronous primary tumours via thoracic radiography and abdominal ultrasonography and their influence on treatment outcome in dogs with soft tissue sarcomas,primary brain tumours and intranasal tumours

Canine soft tissue sarcomas (STS), primary brain tumours and intranasal tumours are commonly treated with radiotherapy (RT). Given the low metastatic potential of these tumours, recommendations regarding imaging tests as staging are variable among institutions. The purpose of our study was to describe thoracic radiographic and abdominal ultrasonographic findings in dogs with these neoplasms and to investigate association of abnormal findings with alterations in recommended treatment. Medical records from 101 dogs, each having thoracic radiographs and abdominal ultrasound performed as part of their staging, were reviewed. In 98 of 101 (97%), imaging abnormalities were detected, 27% of which were further investigated with fine needle aspiration cytology or biopsy. Nine percent of the detected abnormalities were considered serious comorbidities that altered treatment recommendations, including 3 (3%) which were confirmed as synchronous primary neoplasms. These findings may influence recommendations regarding the decision to perform thoracic radiographs and abdominal ultrasound prior to initiation of RT.     

Comparative morphometric analysis of recurrent and nonrecurrent canine basal cell carcinomas: a preliminary report

Background: Most reports of canine basal cell carcinomas (BCCs) focus on morphologic appearance rather than biologic behavior. Rare recurrences and no metastases have been reported in dogs. Quantitative nuclear morphometry may be useful in predicting tumor recurrence. Objective: The aim of the present study was to compare quantitative nuclear parameters of canine BCCs that did not recur within 60 weeks of excision with those that recurred. Methods: Cytologic specimens obtained from spontaneous BCCs from 11 dogs were analyzed by computerized nuclear morphometry. The dogs were monitored by their owners over a period of 60 weeks to detect local recurrence of the tumor; recurrent tumors were confirmed histologically. For each initial tumor specimen, nuclei of at least 100 neoplastic cells were measured by 2 independent observers, and mean nuclear area (MNA), mean nuclear perimeter (MNP), and mean nuclear diameter (MND) were calculated. Results: Six nonrecurrent and 5 recurrent tumors were analyzed. Neoplastic cells from BCCs that subsequently recurred had higher MNA (102.41 ± 4.57 μm²), MNP (36.27 ± 0.61 μm), and MND (11.21 ± 0.27 μm) than cells from nonrecurrent BCCs (MNA 87.66 ± 4.79 μm², MNP 33.51 ± 0.78 μm, MND 10.36 ± 0.29 μm) (P<.001; Mann–Whitney U‐test). Conclusion: Based on these preliminary results, nuclear morphometry may be a useful tool to predict local recurrence of BCCs in dogs.     

Diagnostic accuracy of pre‐treatment biopsy for grading soft tissue sarcomas in dogs

Histologic grade is an important prognostic factor for both local recurrence and metastatic potential with canine soft tissue sarcoma (STS). Pre‐treatment biopsy with identification of tumour grade may aid in prognostication and determination of surgical margins necessary for local control. The purpose of this study was to evaluate the grading accuracy of various pre‐treatment biopsy techniques (wedge, punch, needle‐core) for STS in dogs. Medical records of 68 dogs diagnosed with a STS via pre‐treatment biopsy and confirmed by excisional biopsy were evaluated. The concordance in grade between excisional and pre‐treatment biopsies was 59%. Of the 41% that lacked concordance, 29% of pre‐treatment biopsies underestimated and 12% overestimated grade. The method of pre‐treatment biopsy did not significantly effect grade concordance. Based on these data, needle‐core biopsy appears to be similar in accuracy compared to open biopsy, however, grading determined by pre‐treatment biopsy in general should be interpreted with caution.     

Leukocyte differentiation antigens in canine cutaneous and oral plasmacytomas

Seventeen cutaneous and oral tumours with light microscopic features of plasmacytomas from 16 dogs were studied. Clinically, most neoplasms were benign, although three recurred after excision and three were locally invasive. Tumours most often arose on the pinnae, digits, gingiva, and inguinal regions near areas of chronic inflammation and exhibited variable degrees of plasmacytic differentiation microscopically. Diagnosis of plasmacytoma was confirmed in paraffin-embedded tissues with a panel of leukocyte differentiation antigen markers that included cross-reactive antibodies for Mb-1 (CD79a), CD3, and vimentin and canine-specific antibodies for CD45RA and CD18. Immunoreactivity for Mb-1 and CD45RA, including staining of multinucleate cells and cells with karyomegaly, confirmed a B-cell origin of neoplasms, while staining for CD3 and CD18 revealed an extensive network of infiltrative T-cells and dendritic cells in tumours suggestive of a directed immune response. These findings (i) demonstrate the value of using a panel of antibodies for leukocyte antigens to differentiate plasmacytomas from other cutaneous and oral round cell tumours, and (ii) suggest that immune recognition and responsiveness within tumours may play a role in the behaviour of plasmacytomas in dogs by affecting tumour cell growth and differentiation.     

Prognostic factors for cutaneous and subcutaneous soft tissue sarcomas in dogs

Soft tissue sarcomas (STSs) develop from mesenchymal cells of soft tissues, and they commonly occur in the skin and subcutis of the dog. Although phenotypically diverse with frequently controversial histogenesis, STSs are considered as a group because they have similar features microscopically and clinically. Following resection, local recurrence rates are low in general but vary according to histologic grade and completeness of surgical margins. Complete margins predict nonrecurrence. Even most grade I STSs with "close" margins will not recur, but propensity for recurrence increases with grade. The frequency of metastasis has not been accurately estimated, but it is believed to be rare for grade I STSs and most likely to occur with grade III STSs. However, metastasis does not necessarily equate with poor survival. High mitotic index is prognostic for reduced survival time. Further research is needed to determine more precise estimates for recurrence rates and survival as related to completeness of surgical margins and to delineate potential differences in metastatic rate and median survival time between grades. Other potential indicators of prognosis that presently require further investigation include histologic type, tumor dimension, location, invasiveness, stage, markers of cellular proliferation, and cytogenetic profiles. Common issues limiting prognostic factor evaluation include biases from retrospective studies, small sample sizes, poor verification of metastasis, inconsistent STS classification and use of nomenclature, difficulties in differentiating STS phenotype, and diversity of the study population (stage of disease and treatment status).     

纤维蛋白胶在软组织工程中的应用

纤维蛋白胶是一种天然的细胞外基质,其生物相容性、生物活性、可降解性、可塑性良好,具有三维多孔结构,无细胞毒性,制备方便;近年来,纤维蛋白胶作为支架材料广泛地应用到组织工程研究中。纤维蛋白胶自身或与其他材料结合作为生物支架可应用于干细胞、始祖细胞再生修复脂肪组织、骨、心肌组织、软骨、肝、神经组织、眼、皮肤、肌腱及韧带组织...     

Outcomes and prognostic variables associated with primary abdominal visceral soft tissue sarcomas in dogs: A Veterinary Society of Surgical Oncology retrospective study

Primary abdominal visceral soft tissue sarcomas (STSs) are rare tumours in dogs with little information available on outcomes. The goal of this retrospective, multi‐institutional study was to describe the common tumour types, location and prognostic factors associated with primary abdominal visceral STSs. Medical records were searched for dogs with primary abdominal visceral STSs at six institutions and were retrospectively reviewed. Tumours were graded using the previously described grading scheme for STSs of the skin and subcutis when information in the histopathology report contained adequate details. Forty‐two dogs were included in the study. Five dogs had grade I tumours, 11 had grade II and 15 had grade III tumours. The most common tumour type was leiomyosarcoma (38.1%). The most common tumour locations were the spleen (47.6%) and small intestine (23.8%). The local recurrence rate was low (4.7%). Metastasis was present at the time of surgery in 23.8%, and the overall metastatic rate was 40.4%. Mitotic index of ≥9 was associated with significantly shorter survival time (MST 269 days) compared with a mitotic index of <9 (MST not reached). The MST for grade I STSs was not reached, was 589 days for grade II and 158 days for grade III. Dogs with grade III tumours were more likely to develop metastatic disease. Neither location of the primary tumour nor the histologic subtype was associated with survival time. Histologic grading of abdominal visceral STSs using the previously described scheme is prognostic and should be provided on histopathology reports.     

Morphometrical approach for predicting regional lymph node micrometastatic load in canine mast cell tumours: preliminary results

Canine cutaneous mast cell tumours (MCTs) have a variable biologic behaviour, and accurate staging is necessary to dictate therapy and predict outcome. Regional lymph node (RLN) involvement is a relevant prognostic factor. While obvious lymph node (LN) metastases are relatively easy to be diagnosed, micrometastatic disease recognition is challenging. The main aim of the study was to evaluate the number of mast cells (MCs) in the LNs of clinically healthy dogs ( n = 4, group 1), dogs with inflammatory diseases ( n = 31, group 2) and dogs with cutaneous MCT ( n = 27, group 3), including animals with no RLN metastases (subgroup 3.1), those with occasional MCs in RLNs (3.2) and those with obvious RLN metastasis (3.3). MCs also were morphometrically evaluated for the following nuclear parameters: mean nuclear area (MNA), mean nuclear perimeter (MNP), largest to smallest diameter length (LS ratio), mean nuclear form factor and coefficient of variation of nuclear area. The average percentages of MCs were 0.0 and 0.01 in groups 1 and 2, respectively, and 0.07, 2.4 and 47.1 in subgroup 3.1, 3.2 and 3.3. MNA and MNP were significantly higher in subgroup 3.3 than in group 2 ( P < 0.05). MNA and MNP in subgroup 3.2 suggested the presence of neoplastic MCs; this prediction of micrometastatic load correlated with outcome. Analysis of preliminary results shows that nuclear morphometry is useful to detect micrometastatic disease in RLN of dogs bearing cutaneous MCTs.     

Laparoscopically implanted tissue expander radiotherapy in canine transitional cell carcinoma

Organ motion and injury to adjacent structures limit curative treatment of intraabdominal tumors with external beam radiotherapy. We evaluated the use of Laparoscopically Implanted Tissue Expander Radiotherapy (LITE-RT) to exclude critical structures during irradiation of the urinary bladder in two dogs with transitional cell carcinoma (TCC) using helical tomotherapy. Dogs had histologically confirmed bladder TCC with no metastasis. A custom-shaped tissue expander was placed between the colon and bladder laparoscopically in one dog and during laparotomy in the other. The prescribed radiation dose was 45 Gy to 98% volume of the bladder in 18 fractions of 2.5 Gy. Tumor response and normal tissue effects were monitored with cystoscopy and colonic biopsies before treatment and 3, 6, and 15 months after treatment. Based on treatment plans from inflated vs. deflated tissue expander CT images, there was a mean dose reduction to the colon of 53% and 31% for the two dogs. Interfractional target repositioning was possible by using volumetric megavoltage computed tomography helical tomotherapy. Both dogs had no clinical signs of chronic colitis but did experience mild cystitis during treatment. Tissue expanders became detached, requiring an additional surgery for reattachment, in both dogs. One dog developed a fibrous adhesion resulting in bladder rupture during inflation, which necessitated early device removal. One dog was euthanized for tumor-associated ureteral obstruction at 8 months while the other is alive at 21 months. We conclude that LITE-RT shows promise in treatment of canine bladder TCC due to lack of acute colitis and enteritis.     

Detection and molecular characterization of two canine circovirus genotypes co-circulating in Vietnam

BackgroundCanine circovirus is reported in dogs in many countries, including the USA, China and Thailand. It has been detected in healthy dogs and dogs with diarrhea, hemorrhagic gastroenteritis, and vasculitis. It comprises five genotypes and is frequently found as a coinfection with canine parvovirus-2 (CPV-2).AimTo characterize canine circovirus genotypes co-circulating with CPV-2 in Vietnam.MethodPCR assessment of 81 CPV-2-positive fecal samples from Vietnamese diarrheic dogs up to seven months of age for other viral enteric pathogens, including canine bocavirus, canine adenovirus, paramyxovirus, canine coronavirus, porcine circovirus-3 and canine circovirus. In addition, eight selected full genome sequences of Vietnamese canine circovirus were analyzed and used for phylogeny.ResultsIn total 19.8% of samples were found to be positive for canine circovirus. Phylogeny revealed that the Vietnamese canine circovirus strains were clustered in two different genotypes (genotype-1 and -3). The genetic diversity among Vietnamese canine circovirus was 86.0–87.2%. The nucleotide discrepancy among both genotypes altered the deduced amino acid sequence in 14 and ten residues of the replicase and capsid proteins, respectively. Genetic recombination analysis revealed that the Vietnamese canine circovirus-6 strain has the American and Chinese canine circovirus as its major and minor parents, respectively. Only a single dog revealed triple detections of CPV-2c, Canine circovirus and canine adenovirus (1.2%).ConclusionThe co-circulation of two different genotypes of canine circovirus and CPV-2c in dogs in Vietnam has been illustrated.Clinical relevanceThe mortality rate with CPV-2 only (22%) doubled in dogs with canine circovirus and CPV-2 co-infection.     

Computerized Cytomorphometric Analysis of Nuclear Area,Nuclear Perimeter and Mean Nuclear Diameter in Spontaneous Canine Mammary Gland Tumours

Fifty-two spontaneous canine mammary gland tumours (fibroadenomas (n = 8), tubulopapillary carcinomas (n = 9), solid carcinomas (n = 6), anaplastic carcinomas (n = 7), fibrosarcomas (n = 9), liposarcomas (n = 9) and osteosarcomas (n = 4) were analysed by computer-assisted nuclear morphometry in Hemacolor-stained cytological specimens. Computerized cytomorphometry was performed and the nuclear area, nuclear perimeter and mean nuclear diameter of investigated tumours were assessed. A minimum of 100 nuclei per lesion were examined. The statistical analysis revealed statistically significant differences between benign and malignant neoplasms. The results indicated that computer-assisted nuclear morphometry could be used as an additional method for differentiation of benign from malignant canine mammary gland tumours in cytological specimens.