Intestinal haemangiosarcoma in the cat: clinical and pathological features of four cases

The clinical and pathological features of four cases of feline intestinal haemangiosarcoma are described. All cases were in domestic shorthaired cats and the mean age of the animals (n=3) was 13 years. The tumours originated in the colon, small intestine, ileocaecocolic junction or rectum. The rectal tumour was juxtaposed with an adjacent mast cell neoplasm. Metastasis to mesenteric lymph node occurred in two cases, and in one of these cats there was also abdominal seeding. The histopathological appearance was of a spindle cell neoplasm with vascular differentiation in each case. Immunohistochemical staining for factor VIII-related antigen, an endothelial cell marker, confirmed all four tumours to be of endothelial origin. The neoplastic endothelial cells lining irregular vascular channels were more likely to express the antigen than those forming denser sheets without obvious vascular differentiation.     

Immunohistochemical and ultrastructural investigation of granular cell tumours in dog, cat, and horse.

Six canine, one feline and one equine granular cell tumours (GCTs) were investigated electron microscopically and immunohistochemically. The tumours were tested for reactivity with monoclonal antibodies against vimentin and desmin and with polyclonal antibodies against cytokeratin, S-100 protein, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE). All GCTs were characterized by their PAS positive cytoplasmic granules in light microscopy, which in electron microscopy appeared as lysosome-like granules. In each case two canine GCTs were stained by the antibody against cytokeratin, vimentin and S-100 protein. Cells of the equine GCT showed reactivity with the antiserum against S-100 protein. In the feline GCT no reactivity with any of the antibodies tested was observed. These differences of the immunohistochemical reactions of GCTs suggest a nonuniform histogenesis of GCTs in domestic animals. The reactivity of the tumour cells with the antiserum against NSE is discussed.     

Clinico-pathological aspects of canine cutaneous and mucocutaneous plasmacytomas

In this study the clinico-pathological aspects of cutaneous and mucocutaneous plasmacytomas were investigated in 63 dogs (one dog with two tumours). The tumours were most commonly observed in the skin of the trunk and legs. Yorkshire Terrier (n = 8) was the most commonly affected breed and males were affected more commonly than females (36 versus 23, respectively). Plasmacytomas were histologically classified into mature, hyaline, cleaved, asynchronous, monomorphous blastic and polymorphous blastic cell types. Monomorphous blastic cell type was the most frequent type (n = 21), followed by cleaved (n = 19) and asynchronous (n = 11) cell types. Secondary amyloid depositions were observed in eight cases. Immunohistochemical staining showed monoclonal lambda light chain positivity in all cases. In the immunohistochemical staining for cyclin D1, which is a prognostic marker in human plasma cell tumours, moderate numbers of positive tumour cells were observed in only one case of (muco)cutaneous plasmacytoma. All other cases were negative or contained few positive tumour cells. On the other hand, high numbers of tumorous plasma cells reacted positively with cyclin D1 in three out of six cases of canine multiple myelomas. Prognosis of the (muco)cutaneous plasmacytomas was good, except in one dog which developed a lymphoma afterwards. No significant correlations were observed between the cell type and the location of the tumour, presence of amyloid or prognosis.     

Granular cell myoblastoma in the tongue of a dog: A case report

A granular cell myoblastoma was found in the dorsal side of the tongue of a 9‐year‐old female mongrel Pinscher. Macroscopically the tumour was white, well circumscribed, and 1½> cm in diameter. Microscopically the tumour cells were arranged in small compact nests or cords with delicate, poorly vascularized collagen bundles in between. A cinar structures were found, also a few mitotic figures were present. Cytoplasmic granules showed a positive periodic acid Schiff reaction. Ultrastructural features included indented nuclei and small‐sized vesicular cytoplasmic granules.

The histogenesis of the neoplasm remains uncertain.     

Alkaline phosphatase reaction of canine mammary mixed tumours: a light and electron microscopic study

Alkaline phosphatase (ALK-P) reactions at the light and electron microscopic levels were performed on eight canine mammary mixed tumours. In the morphologically normal gland next to the tumours, the myoepithelial cells and the stromal tissues near the acinar basement membranes both showed a positive ALK-P reaction by light microscopy. At the electron microscopic level, those parts of the myoepithelial cell membrane that were in contact with other cells--myoepithelial or lumenal epithelial--showed an ALK-P-positive reaction, as did the adjacent stromal tissue. The characteristic tumour cells, at sites of early proliferation, were ALK-P-positive, while in the mucoid and chondroid areas of the mixed tumours they were largely ALK-P-negative by light microscopy. By electron microscopy, those neoplastic cells which were in contact with other cells typically showed a positive ALK-P reaction, while those cells which were in contact with mucoid or chondroid matrix were largely negative. Although the cytoplasmic filaments of the neoplastic cells were 10 nm thick, and those of normal myoepithelial cells were 6 to 8 nm thick, the observations reported provide further evidence for the view that the essential cells of the canine mammary mixed tumour are derived from myoepithelial cells.     

Nine cases of granular cell tumors in B6C3F1 mice

The histological characteristics of 9 cases of granular cell tumors (GCTs) observed in B6C3F1 mice were examined to determine their cellular origin. Seven of the 9 cases were found in the uterus and other 2 cases were in the subcutaneous tissue. Tumor cells had abundant granules in the cytoplasm which were stained with PAS and were resistant to diastase treatment. Ultrastructurally, the granules were identified as lysosomes. The cell surface had cytoplasmic processus showing interdigitation with adjacent cells. A character feature of the tumor cells was the presence of a desmosome-like structure on their cell surface but no basal lamina was demonstrated. Although GCTs have been considered to be derived from Schwann cells on the basis of their ultrastructural features and S-100 protein-immunopositive findings, the absence of basal lamina in the present cases may raise a controversy as to their origin.     

The radiological features of non-osteogenic malignant tumours of bone in the appendicular skeleton of the dog: a review of thirty-four cases

The clinical features, sites of origin and radiological changes in 34 dogs with 38 histologically proven non-osteogenic malignant tumours of the appendicular skeleton are reported. The incidence of such tumours when compared with the number of osteosarcomas recorded during the same period is much higher than in previously reported series. A wide variety of tumour types was recorded, fibrosarcomas (nine cases), metastatic deposits (eight cases) and haemangiosarcomas (five cases) being the most common. No distinctive features could be related to histological type, but only one tumour in this group demonstrated radiological signs indistinguishable from those previously classified as characteristic of osteosarcoma (Gibbs, Denny & Kelly, 1984). Lung metastases were detected radiographically in approximately 15 per cent of cases. Of eight dogs treated, either by amputation or surgical excision, three are known to have survived without recurrence for more than two years.     

Deionised water as an adjunct to surgery for the treatment of canine cutaneous mast cell tumours

Medical records of 55 dogs with a diagnosis of cutaneous mast cell tumour were reviewed. Twenty-seven of the dogs were treated with surgery plus deionised water and the remaining 28 with surgery alone. A survival analysis was performed to determine whether deionised water, as an adjunct to surgery for cutaneous mast cell tumour, affected survival time or time to tumour recurrence. Dogs in which mast cell tumour recurred had a significantly shorter survival time compared with dogs with no recurrence (P=0.05), regardless of the method of treatment. A significant negative association between tumour recurrence and method of treatment (P=0.0097) and clinical stage (P=0.0223) was observed. Dogs treated with surgery and deionised water had a significantly shorter time to recurrence of their mast cell tumour (P=0.0113). Based on these results, deionised water does not appear to be beneficial in prolonging survival time or time to tumour recurrence for dogs with cutaneous mast cell tumours.     

Delayed metastasis of ocular squamous cell carcinoma following treatment in five horses

Identification of regional and/or distant metastasis following treatment and local resolution of primary ocular squamous cell carcinoma (SCC) was observed in 5 horses. In all cases, identification of metastasis occurred at least 18 months following treatment of the primary ocular lesions. In 3 cases, invasion of blood or lymphatic vessels by neoplastic cells was identified in the excisional biopsies of the primary tumour. Two horses developed SCC at 2 or more separate sites. At the time metastases were identified, there was no evidence of local recurrence of the ocular tumour in any of the horses. These cases confirm the importance of long‐term monitoring of horses for metastatic disease following treatment of ocular SCC even in the absence of local recurrence.     

Cytological features of canine ovarian tumours: a retrospective study of 19 cases

The cytological features of 19 histologically confirmed canine ovarian tumours were retrospectively examined. Seven cases were cytologically classified as papillary adenocarcinoma, eight cases as granulosa cell tumours, two cases as mature ovarian teratomas, one case as a dysgerminoma and one case as a mixed granulosa cell tumour/dysgerminoma. On cytology, papillary adenocarcinoma was characterised by a papillary glandular pattern and tight cohesiveness. Granulosa cell tumours showed monolayered clusters of loosely cohesive granulosa cells. Call-Exner-like bodies were found in five of seven cases. Granulosa cells appeared to be heterogeneous and usually contained several intracytoplasmic vacuoles. Teratoma was characterised cytologically by keratin debris (two cases) and a mixture of epithelial cells with sebaceous, basaloid, columnar/palisading or ciliated appearance (one case). The dysgerminoma contained severely atypical round cells admixed with small lymphocytes. The mixed dysgerminoma/granulosa cell tumour had a mixture of germinal and granulosa cells. Cytological diagnosis was in agreement with histopathology in 18 of 19 (94.7 per cent) cases.     

Preliminary results of maxillectomy in the dog and cat

Maxillectomy was used in the treatment of 23 dogs and four cats with oral tumours and one dog with osteomyelitis. The major post-operative complication was wound dehiscence. All dehiscences occurred in dogs with tumour epicentres caudal to PM¹. Maxillectomy in eight dogs with oral fibrosarcoma gave disappointing results (median survival time of 7 months and a median tumour-free interval of 3½ months). Three of four dogs with squamous cell carcinoma were tumour free after a minimum follow-up period of 6 months; two of these dogs received orthovoltage radiation therapy following surgery. Maxillectomy provided excellent local control of benign tumours: three epulides and one atypical odontogenic tumour did not recur (minimum follow-up period was 10 months); an osteoma recurred after 17 months. Four cats, three with squamous cell carcinoma and one with fibrosarcoma, developed local tumour recurrence within 4 months.     

Squamous cell carcinoma in sheep in Saudi Arabia.

Squamous cell carcinoma was recorded in 22 Nadji and 3 Maeimi sheep aged 3-6 years, of which 22 were females. Sixteen tumours involved the eyes, 7 occurred in the skin at different body sites, one developed in the ear and another in the rectum. In five cases secondary deposits were seen in the lymph nodes, nasal passages and upper lip. Surgical treatment was successful in the early stages of tumour development, but in advanced cases recurrences were noted. Histologically the tumours were typical for squamous cell carcinoma and most of them were well differentiated. Solar radiation was pointed out as a possible factor in the aetioloy of the tumour.     

High lysyl oxidase expression is an indicator of poor prognosis in dogs with cutaneous mast cell tumours

Mast cell tumour (MCT) is one of the most frequent skin tumours in dogs. Due to their unpredictable biological behaviour, MCTs often cause several therapeutic frustrations, leading to investigation regarding prognostic markers. Lysyl oxidase (LOX) is an enzyme that promotes extracellular matrix stability and contributes to cell migration, angiogenesis and epithelial-mesenchymal transition. Its expression positively correlates with poor prognoses in several human and canine mammary cancers. The aim of this study was to characterise the immunohistochemical expression of LOX in MCT samples and compare it with histological grading and post-surgical survival. Twenty-six tumours were submitted to immunohistochemistry for LOX expression evaluation. All samples were positive for LOX, with variable percentages of cytoplasmic and nuclear positivity. Cytoplasmic positivity was significantly higher in high-grade MCTs (P = .0297). Our results indicate that high expression of cytoplasmic LOX in neoplastic mast cells is an indicator of poor prognosis for canine cutaneous MCTs.     

Soft tissue sarcomas and mast cell tumours in dogs; clinical behaviour and response to surgery

OBJECTIVE: To characterise the types of canine soft tissue sarcoma and mast cell tumour treated surgically at the University Veterinary Centre, Sydney. To evaluate the success of surgical treatment of these tumours and identify variables predictive of local recurrence and survival. To establish whether conclusions drawn from previous international studies are applicable to the University Veterinary Centre, Sydney, dog population and vice versa. DESIGN: Clinical presentation and results of surgical excision of 54 soft tissue sarcomas and 70 mast cell tumours affecting the trunk and limbs of dogs at the University Veterinary Centre, Sydney, between 1989 and 2001 were reviewed retrospectively. RESULTS: Cross-bred dogs and Rhodesian Ridgebacks were at significantly greater risk of developing soft tissue sarcomas, and Boxers, Australian Cattle Dogs and Staffordshire Bull Terriers were at significantly greater risk of developing mast cell tumours than other breeds. Fine needle aspiration biopsy yielded a correct diagnosis in 62.5% of soft tissue sarcomas and 96% of mast cell tumours. Local recurrence was encountered after surgical excision in 7.4% of soft tissue sarcomas and 7.3% of mast cell tumours. Metastasis occurred in 6% of soft tissue sarcomas and 12% of mast cell tumours. The most significant risk factors for local recurrence were contaminated surgical margins (soft tissue sarcomas) and histological grade (mast cell tumours). Due to the low number of animals experiencing metastasis, no conclusions could be drawn about significant risk factors. CONCLUSIONS: Aggressive surgical management of soft tissue sarcomas and mast cell tumours is associated with a low incidence of local recurrence. The type, location and behaviour of mast cell tumours and soft tissue sarcomas in the population of dogs presented to the University Veterinary Centre, Sydney are similar to those reported by others.     

Distribution of nuclear DNA-content in canine mammary tumours

It is well established that nuclear DNA-content contributes valuable information concerning tumour behaviour in a vast number of human neoplasms (compare Auer and Zetterberg, 1984 and Zetterberg and Auer 1984 for review). The authors have attempted for the first time to apply this concept to clinical veterinary medicine and in the present investigation 17 dogs with mammary tumour were studied retrospectively. Microspectro-photometric DNA-measurements were performed and correlated to the clinical course defined as distant recurrence free interval. The results suggest that a relationship exists between nuclear DNA-content of the breast cancer cells and prognosis. Tumours exhibiting DNA-values within the limits of normal tissue correlate with a favourable prognosis in the sense that all dogs with diploid tumour cell DNA-content under study had survived for more than one year without recurrence of the tumour. In contrast 50 per cent of the tumours with increased and scattered DNA-values developed metastasis within one year whereas the other 50 per cent were disease free after this period. It is therefore proposed that cytophotometric analysis of DNA may be used in the assessment of prognosis in dogs with malignant breast tumours.     

Expression of NOS and VEGF in feline mammary tumours and their correlation with angiogenesis

In order to define the role of nitric oxide (NO) in feline mammary tumours, the expression of endothelial or inducible nitric oxide synthase (e/iNOS) and vascular endothelial growth factor (VEGF), and their relationship with angiogenesis, was investigated in 23 feline mammary tumours (two hyperplastic, 19 adenocarcinoma, one osteosarcoma and one squamous cell carcinoma) by immunohistochemistry. Tumour angiogenesis was assessed by CD31 immunostaining and was expressed as microvessel density (MVD). In general, iNOS immunoreactivity was localised in tumour cells and occasionally in stromal myofibroblasts, whereas eNOS and VEGF were localised in the cytoplasm of tumour epithelial cells and endothelium. In malignancy, expression of iNOS increased from well- to less-differentiated phenotypes (Grades 1-3) and was significantly higher in G3 and G2 when compared with G1 cases. However, increasing eNOS expression was limited only in hyperplastic lesions and showed no significant changes among the grades. In addition, expression of iNOS was positively correlated with VEGF and MVD in feline mammary tumours and both measures were significantly greater in less differentiated phenotypes (P<0.05). In conclusion, the expression of NOS isoforms in feline mammary tumours depended on tumour grade, and the positive correlations between iNOS and angiogenic markers suggests that iNOS synthesised by tumour cells promotes tumour growth. Thus, iNOS can be used as an important immunohistochemical marker to determine the degree of malignancy and prognosis of feline mammary carcinoma.     

Histopathological and immunohistochemical characteristics of two canine lipid-rich mammary carcinomas

Clinicopathological and immunohistochemical findings of two uncommon canine lipid-rich mammary carcinomas are described. The predominant histological feature in both tumours was the presence of at least 80% of cells with intracytoplasmic vacuoles which stained positively with Sudan IV but not with alcian-blue periodic acid-schiff method. In both tumours, small groups of non-vacuolated cells were identified among the vacuolated cells. However, histological and immunohistochemical differences were also found between these tumours. Thus, one of them was composed of tumour cells with a large and single vacuole, which were arranged in lobular pattern, while the other neoplasm showed an intraductal growth of tumour cells with a fine vacuolated cytoplasm. Immunohistochemically, in the first tumour most vacuolated cells were positive for CK (cytokeratin)8-7, indicating a secretory epithelial immunophenotype while CK5 and CK8-7-expressing non-vacuolated cells were associated with luminal duct immunophenotype. However, in the second tumour the expression of CK14 in most of vacuolated cells and alpha-smooth muscle actin (alpha-SMA) in non-vacuolated cells, alone or in combination with CK5 suggested a myoepithelial immunophenotype for both cell types. These results suggest heterogeneity of the cell type and growth pattern for this type of canine tumour as has been described in women but not in dogs.     

Evaluation of histological grade and histologically tumour‐free margins as predictors of local recurrence in completely excised canine mast cell tumours

Completeness of mast cell tumour (MCT) excision is determined by assessment of histologically tumour‐free margins (HTFM). The HTFM width necessary to prevent local recurrence (LR), recognized as histologic safety margin (HSM) in human oncology, has not been defined. We hypothesized that HTFM width would correlate with risk for LR and high‐grade tumours would require wider HTFM than low‐grade tumours. Records of dogs with completely excised MCTs were included. Signalment, two‐tier tumour grade, tumour size, HTFM width, recurrence and therapy data was collected. High‐grade (n = 39) tumours were more likely to recur than low‐grade (n = 51) tumours (35.9% versus 3.9%), P < 0.0001, with no association between HTFM width and LR. Twenty‐nine percent of low‐grade tumours had HTFM less than 3 mm; none recurred. Narrow (≤3 mm) histologic margins are likely adequate to prevent LR of low‐grade tumours. High‐grade tumours have significant risk of LR regardless of HTFM width.     

Canine Transmissible Venereal Tumour: Asessment of Mast Cell Numbers as Indicators of the Growth Phase

Mast cells are immune cells that are involved mainly in type 1 hypersensitivity reactions, and they have been implicated in tumour angiogenesis. In this study we assessed the presence of mast cell numbers and microvessel density during the progression and regression stages of natural spontaneous canine transmissible venereal tumours (CTVT). Mast cells were demonstrated by histochemical staining with toluidine blue, alcian blue and safranin O. Microvessel counts were demonstrated by immunohistochemical labelling with an antibody against the endothelial cell marker factor VIII. Mitotic cells, apoptotic cells and tumour infiltrating lymphocytes were counted from haematoxylin–eosin-stained sections. Tumour fibrosis was evaluated on Masson's trichome-stained sections. The results showed that progressing tumours had significantly higher mast cell counts and microvessel counts at the invasive edges of the tumours than did regressing tumours. In both the progressing and regressing tumours, microvessel counts were significantly positively correlated with mast cell counts. Regressing tumours had significantly higher mast cell counts of the whole tumour than progressing tumours. The results also showed that progressing tumours had significantly higher mitotic rate than regressing tumours, and fibrosis and apoptosis were significantly higher in regressing tumours than progressing tumours. There were no significant differences between the biochemical and haematological values of dogs with progressing and regressing tumours. These results suggests that mast cells play a role in CTVT progression probably by promoting vascularization at the invasion front during the progression phase, and that mast cell count could be used as one of the histological factors to indicate growth stage of CTVT.     

Primary and metastatic carcinomas in the digits of cats

In the period 1993-1998, digital carcinomas in 64 cats were examined. In all animals primary complaints were painful digit(s). Eight cats had a primary squamous cell carcinoma which involved one digit or two adjacent digits of one leg. Fifty-six cats had metastases of a pulmonary carcinoma in the digits, and in general multiple digits of different legs were involved. In many of these cats metastases also occurred in other organs, including the skin and muscles. No primary sweat gland carcinomas of the digits were seen. Primary squamous cell carcinomas of the digits were characterized by cornification and the absence of PAS-positive cells, PAS-positive secretory material. Immunohistochemically, these neoplasms stained negative with the monoclonal antibody CAM 5.2 directed against Keratin 8 (K 8). The metastases of pulmonary carcinomas to the digits showed one or more of the following histological features: goblet cells, ciliated epithelial cells, PAS-positive cells or lakes, and/or a PAS-positive lining of luminal membranes and no cornification. Immunohistochemically, they showed positive staining for CAM 5.2 (K8). Thoracic radiographs from three cats with a primary squamous cell carcinoma showed no abnormalities, whereas all cases of metastases from a pulmonary carcinoma to the digits available for follow-up showed evidence of a primary pulmonary carcinoma on radiography and/or postmortem examination (25 out of 56). The conclusion of this study was that most carcinomas in the digits of cats were metastases of a primary pulmonary carcinoma (87.5%). Primary squamous cell carcinomas occurred infrequently. The prognosis of metastases of a pulmonary carcinoma in the digits is poor with an average survival time of 4.9 weeks, in contrast to 29.5 weeks in cats with a squamous cell carcinoma. These data stress the importance of taking thoracic radiographs of cats with digital tumours before surgical intervention.