Cryosurgical Treatment of Palpebral Neoplasms: Clinical and Experimental Results

Cryosurgical treatment of canine eyelid neoplasms has resulted in destruction of the tumors while maintaining acceptable cosmetic results. Both clinical experience and experimental studies have shown the normal canine palpebra to be quite resistant to excessive permanent deformity secondary to freezing. Significant histologic changes after cryotherapy are loss of adnexal structures, and depigmentation and thinning of the epithelium. Cryosurgery is recommended as an alternative treatment to surgical excision of eyelid tumors in dogs.     

Prevalence and treatment of palpebral neoplasms in the dog: 200 cases (1975-1983)

The prevalence and treatment of 255 eyelid tumors in 200 dogs was related to breed, age, sex, location, and tumor type. Treatment methods included cryosurgery and surgical excision. The mean age of all dogs with eyelid tumors was 9.6 years (+/- 0.2 SEM). Beagles, Siberian Huskies, and English Setters had a higher risk of tumor development, whereas the mixed-breed dogs had a lower risk. Sebaceous tarsal gland adenomas, benign melanomas, and papillomas were observed most often (88%). Malignant tumors (melanoma, adenocarcinoma, basal cell carcinoma, mast cell tumor, squamous cell carcinoma, hemangiosarcoma, and myoblastoma) comprised 8.2% of the tumors. Tumor recurrence rates between dogs treated with cryosurgery and those treated surgically were not significantly different (15.1% and 10.5%, respectively). The mean recurrence time after cryosurgery was 7.4 months (+/- 1.9 SEM), whereas it was 28.3 months (+/- 7.2 SEM) after surgical excision. Using either treatment, the long-term side effects were similar. The overall cosmetic appearance was observed to be better with cryosurgery.     

Leiomyoma of the third eyelid in a dog

A 14‐year‐old neutered male Dachshund presented for the evaluation of oculus dexter (OD) third eyelid elevation ongoing for approximately 2 months. Complete ophthalmic examination revealed a large, nonpainful, well‐demarcated, soft mass at the base of the right third eyelid causing elevation and mild hyperemia. The mass was freely moveable with the third eyelid, and no right globe deviation was noted. No other abnormalities were noted on physical examination, routine blood chemistry, complete blood count, serum T4, urinalysis, or urine cortisol/creatinine ratio. Ocular B‐mode ultrasonography showed an anechoic, well‐demarcated, homogenous, soft tissue mass at the base of the third eyelid with no orbital extension. A leiomyoma was diagnosed after multiple punch biopsies were obtained from the palpebral surface of the mass. The right third eyelid was excised surgically. Histopathology confirmed a completely excised, nodular, unencapsulated, expansile mass within the third eyelid. Positive smooth muscle actin and negative S‐100 immunohistochemistry confirmed a leiomyoma. Bundles of normal smooth muscle were also present adjacent to the mass. The mass was compressing the adjacent lacrimal gland and associated with moderate dacryoadenitis. Twelve months postoperatively, the right globe position and motility remain normal with no evidence of mass regrowth. To the author's knowledge, this is the first reported case of a leiomyoma of the third eyelid in any species. In this case, the mass was completely excised and no regrowth has occurred twelve months after surgery. This case along with independently reviewed canine third eyelids clearly demonstrates the presence of smooth muscle within the canine third eyelid.     

Occurrence and expression of p53 suppressor gene and c‐Myc oncogene in dog eyelid tumors

Purpose To detect the occurrence and expression of the suppressor gene p53 and of the oncogene c‐Myc in eyelid tumors of dogs using the PCR, RT‐PCR, PCR‐ELISA and RT‐PCR‐ELISA techniques. These genes have not been described in dog eyelid tumors before. Methods Nine samples of eyelid or third eyelid epithelial tumors were obtained from the archives of the Department of Veterinary Pathology. Tumor diagnosis was confirmed by evaluation of hematoxylin‐eosin stained sections, and immunohistochemistry for cytokeratin AE1/AE3 and vimentin V9. A canine mammary tumor was used for positive control. Agarose gel electrophoresis, PCR‐ELISA and RT‐PCR‐ELISA were used to detect p53 and c‐Myc genes. Results The occurrence of p53 was detected in most of the eyelid tumors and third eyelid tumors studied (88.8%, n = 8) and was expressed in 75% of the positive samples, as indicated by ELISA. The c‐Myc gene was found in 77.7% (n = 7) of the samples and was expressed in eight samples. Conclusions Eyelid and third eyelid tumors of dogs express both the p53 and the c‐Myc genes as shown by PCR and RT‐PCR. However, PCR ELISA and RT‐PCR ELISA were more efficient in assessing occurrence and expression of these genes because they identified amplified products that were not detected by agarose gel electrophoresis.     

Ocular oncology

Neoplasia can affect all ocular tissues. The clinical appearance of ocular neoplasia can vary considerably depending on the specific tissue involved. Intraocular neoplasia may mimic or incite ocular inflammatory disease in addition to causing hyphema or secondary glaucoma. Intraocular neoplasms can be primary tumors or may be secondary to metastatic disease or systemic neoplasia. Primary neoplasms, metastatic tumors, tumors extending from adjacent structures, and systemic neoplasms can also affect the adnexal tissues. Many ophthalmic tumors are histologically benign but are locally invasive and, within the confined space of the eye or orbit, can produce significant tissue distortion. Certain ocular neoplasms, such as many canine eyelid tumors, are amenable to simple excision and can be adequately managed in general practice. The evaluation and treatment of other ophthalmic neoplasms, however, may require the additional equipment available only in larger specialty practices, such as computed tomography and radiation therapy. Early diagnosis of ocular neoplasia is an important aspect of successful management.     

Cyclooxygenase-2 expression in canine mammary tumors

Mammary tumors are the most common neoplasms in female dogs. Induction of cyclooxygenase-2 (COX-2) has been implicated in various cancers in humans. However, expression of COX-2 has not been investigated in canine mammary tumors. Normal mammary gland (n = 4), simple or complex adenomas (n = 63), and simple or complex adenocarcinomas (n = 84) were studied by immunohistochemistry. Results showed that COX-2 was not expressed in the normal gland but was detected in 24% of adenomas and in 56% of adenocarcinomas (P < 0.001). The incidence of COX-2 expression and the intensity of the COX-2 signal were higher in adenocarcinomas than in adenomas (P < 0.001). These results demonstrate for the first time that COX-2 is induced in a proportion of canine mammary tumors and that COX-2 expression is more frequent and more intense in malignant than in benign tumors, suggesting a potential role for COX-2 in canine mammary tumorigenesis.     

Oral doxycycline, niacinamide and prednisolone used to treat bilateral nodular granulomatous conjunctivitis of the third eyelid in an Australian Kelpie dog

A 5-year-old, female neutered, Australian Kelpie presented with a 2-month history of dramatic bilateral erythematous thickening of the third eyelids. Ophthalmic examination demonstrated raised, pink to red, irregular thickening of the entire palpebral surface of both third eyelids. There were no other ocular abnormalities. A surgical biopsy was taken from each third eyelid. Histopathologic examination revealed sheets of macrophages, plasma cells, lymphocytes, and occasional fibroblasts and neutrophils infiltrating the third eyelid stroma. A diagnosis of chronic granulomatous conjunctivitis was made. Grossly and histopathologically this case closely resembles previously described cases of nodular granulomatous conjunctivitis involving the third eyelids of Collie dogs. This report describes an unusual case of nodular granulomatous conjunctivitis isolated to the third eyelids in an Australian Kelpie. Resolution of the condition was achieved with a combination of oral doxycycline, niacinamide and prednisolone.     

RADIOGRAPHIC CHANGES ASSOCIATED WITH DIGITAL, METACARPAL AND METATARSAL TUMORS, AND PODODERMATITIS IN THE DOG

Fifty-two of digital, metacarpal or metatarsal canine tumors and 48 pododermatitis lesions were reviewed retrospectively. The tumors were divided into 42 malignant neoplasms, 6 benign neoplasms and 4 non-neoplastic tumor-like growths. The distribution and radiographic changes of the lesions associated with the tumors and inflammation were compared. Pododermatitis and benign processes could not be radiographically differentiated from malignant neoplasms of the foot; however, lesions exhibiting osteolysis were more likely (p < 0.05) to be associated with malignant neoplasms.     

Cutaneous plasmacytomas in dogs: a morphologic and immunohistochemical study

Forty-nine cutaneous plasmacytomas in 46 dogs were studied. Tumors occurred at solitary sites in middle-aged to old dogs (mean age, 9.7 years) and most commonly involved the skin of the digits, lips, and ears. Initial diagnosis was made on the basis of light microscopic morphologic findings. Tumors were graded according to the extent of cellular differentiation and immunoreactivity to a panel of immunohistochemical markers (cytokeratins, canine IgG F[ab]2, neurofilament, neuron-specific enolase, S-100 protein, and vimentin). Immunoreactivity was limited to antibodies directed at canine IgG F(ab)2 and vimentin. Vimentin immunoreactivity was usually greater than that of canine IgG F(ab)2, but there was no correlation between immunoreactivity and histologic grade of the tumors. Thirty-six of 39 dogs (92.3%) followed (mean follow-up, 13 months) were cured by surgical excision. The results of this study indicate that canine cutaneous plasmacytomas are benign neoplasms that should be included in the differential diagnosis of cutaneous round cell tumors in dogs.     

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF ODONTOGENIC NEOPLASMS IN DOGS

Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board‐certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty‐three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass‐associated tooth displacement in 85.2% (23/27). Mass‐associated cyst‐like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra‐osseous (10/15) or intra‐osseous (5/15) masses. Intra‐osseous canine acanthomatous ameloblastomas were more likely to have mass‐associated cyst‐like structures and were subjectively more aggressive when compared with extra‐osseous canine acanthomatous ameloblastomas. Amyloid‐producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst‐like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra‐osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass‐associated tooth destruction was appreciated more often with dental radiographs and extra‐oral tumor extension was identified more often with CT.     

Melan A and S100 protein immunohistochemistry in feline melanomas: 48 cases

Immunohistochemistry, using a monoclonal antibody to Melan A and a polyclonal antibody to S100 protein, was applied to 48 formalin-fixed, paraffin-embedded specimens of feline melanoma. Forty-two cutaneous, three oral, one mucocutaneous, and two metastatic melanomas comprised the tumors. Thirty-two tumors (67%) were positive for Melan A and 42 (87.5%) were positive for S100. All but one of the tumors that were positive for Melan A were also positive for S100. S100 was detected in 11 of 16 tumors that were negative for Melan A. Seventy-five percent (9 of 12) of amelanotic melanomas were negative for Melan A. Normal adrenal cortex, the cerebellum, and the skin had cells that were positive for Melan A. Sebaceous adenoma was the only nonmelanocytic tumor examined that reacted with antibody to Melan A. Although less sensitive than S100 protein, Melan A is more specific for melanoma and is useful in differentiating feline cutaneous melanoma from the more common pigmented basal cell tumor.     

Relationship between receptors for insulin-like growth factor- I, steroid hormones and apoptosis-associated proteins in canine mammary tumors

In the veterinary literature there are few data concerning the expression of insulin-like growth factor type I (IGF-IR) in the canine mammary gland tumors. The aim of the present study was the evaluation of IGF-IR expression and its correlation to the expression of estrogen receptor alpha (ERalpha) and progesterone receptor (PR), proteins: Bcl-2, Bax, p53 in canine mammary gland tumors, and also a correlation with other features: bitch's age, tumor diameter, histologic type of tumor, degree of histologic malignancy, proliferate activity. The study was done on 112 epithelial neoplasms: 21 (19%) were adenoma, 38 (34%) complex carcinoma (adenocarcinoma), 47 (42%) simple carcinoma (adenocarcinoma) and 6 (5%) solid carcinoma. Histochemistry and immunohistochemistry methods were employed. It was shown that more common and/or higher IGF-IR expression in cells of canine mammary gland tumors was related to the histologic type of cancer of worse prognostic (solid and simple carcinoma), high histologic degree of malignancy (III degrees) but the statistical analysis did not reveal any significant differences. We observed the high degree of IGF-IR expression in tumors which displayed the high ERalpha and PR expression. These results suggest the involvement of IGF-IR in the development of hormonosensitive canine mammary tumors. Additionally, the significant positive correlation between expression of IGF-IR and p53, Bax was found. Our study provides some evidence that interactions exist between the IGF-IR and these apoptosis-associated proteins may contribute to the development and progression of canine mammary gland tumors. These results require further investigations.     

Canine ocular gliomas: a retrospective study

Objective The purpose of this paper is to classify glial tumors observed in the canine retina and optic nerve, describe the histopathological features and provide prognostic information on these neoplasms. Methods The database of the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) was searched to collect canine glioma cases. Clinical and follow-up information was gathered from submission forms and an extensive follow-up survey. Slides were reviewed to describe the histopathological characteristics of the neoplasm and classify them. Immunohistochemistry for Glial Fibrillary Acidic Protein (GFAP) was performed in all cases. Results 18 canine glioma cases were found in the COPLOW database. There was no breed or gender predilection. The mean age was 9.33 ± 3.67 years. Follow-up information was available for 12 dogs, 8 of which were dead at the time of most recent contact, with a survival time ranging from 0 days (globes received after euthanasia) up to 20 months post-enucleation. In 6 of the 8 dogs that had died during this stud), tumor extended to the margin where the optic nerve had been sectioned. Light microscopic examination of the optic nerve of the affected eyes of four dogs that were still alive during this study revealed no tumor at this surgical margin. One neoplasm was classified as low-grade astrocytoma, 5 tumors as medium-grade astrocytoma, 11 tumors as high grade-astrocytoma and 1 tumor as oligodendroglioma. GFAP was positive in all but two tumors. Conclusion Retinal and optic nerve gliomas may be considered as differential diagnoses of intraocular and orbital masses. The metastatic potential appears to be low, but ascending invasion into the ventral aspect of the brain is possible.     

Use of the lip-to-lid flap for replacement of the lower eyelid in five cats

OBJECTIVE: To report outcomes after reconstruction of the lower eyelid following resection of squamous cell carcinoma (SCC). STUDY DESIGN: Retrospective study. ANIMALS: Five cats (6 eyelids). METHODS: Case records were reviewed for breed, sex, surgical findings, complications, and outcome. RESULTS: Six eyelids were reconstructed in 5 cats; functional outcome was excellent. Neither wound breakdown nor flap failure occurred. An area of superficial necrosis occurred in 1 cat; this spared the eyelid margin and healed by secondary intention without any cosmetic or functional effect. One cat was euthanatized 18 months later because of a nasal mass. The relationship between the nasal mass and the previously excised SCC was not established. CONCLUSIONS: Reconstruction of the lower eyelid using a lip-to-lid flap yields satisfactory functional and cosmetic results in cats. CLINICAL RELEVANCE: A lip to lid flap is a successful form of single-stage reconstruction after lower eyelid excision in cats.     

Diagnostic immunohistochemistry of canine round cell tumors

Sixty-five canine skin neoplasms studied using immunocytochemistry, included 22 histiocytomas, 18 amelanotic melanomas, 14 cutaneous lymphosarcomas, six mast cell tumors, and five transmissible venereal tumors. Formalin-fixed, paraffin-embedded sections were stained using the avidin-biotin-peroxidase complex (ABC) immunoperoxidase technique for reactivity with S-100 protein, kappa and lambda immunoglobulin light chains, alpha-1-antitrypsin, alpha-1-antichymotrypsin, leukocyte common antigen (LCA), neuron-specific enolase, keratin, cytokeratin, muramidase, and vimentin. Detection of S-100, kappa and lambda light chains, neuron-specific enolase, and vimentin were most useful for screening these neoplasms. None of the markers examined was consistent in staining histiocytomas. While reactivity of S-100 (ten cases) and neuron-specific enolase (ten cases) was detected in some amelanotic melanomas, lambda light chain immunoglobulin (eight cases) was relatively consistent in cutaneous lymphomas. Mast cell neoplasms reacted with avidin and, therefore, were positive, even on negative control sections. Vimentin reacted strongly on all amelanotic melanomas and transmissible venereal tumors examined. These antibodies are helpful adjuncts in the differential diagnosis of canine skin tumors.     

A survey on neoplasia in domestic species over a 40-year period from 1935 to 1974 in the Republic of South Africa. II. Tumours occurring in sheep

A survey was carried out on all ovine neoplasms recorded in the registration files of the Section of Pathology of the Veterinary Research Institute at Onderstepoort over a 40-year period from 1935 to 1974. The neoplasms were divided and tabulated into 8 groups according to body systems or tissue types. Out of a total of 673 neoplasms, 436 (64,8%) were cases of jaagsiekte (pulmonary adenomatosis). Of the remaining 237 neoplasms, 41,3% involved the skin. Eighty per cent of the cutaneous neoplasms were squamous cell carcinomas which varied from well-differentiated to anaplastic. The majority occurred on the head, in particular on the ears, frontal region and on the eyelids or nictitating membrane. Several factors have been suggested to explain the high incidence of squamous cell carcinomas on the head. Lymphosarcomas were the 3rd most commonly encountered tumours, whilst a significant number of hepatocellular carcinomas also occurred. A variety of tumours of connective tissue origin were recorded, the most common of which arose from fibrous tissue and cartilage.     

C-kit expression in canine mucosal melanomas

The c-kit receptor is responsible for transmission of promigration signals to melanocytes; its downregulation may be involved in malignant progression of human melanocytic neoplasms. Expression of this receptor has not been examined in normal or neoplastic melanocytes from dogs. In this study, 14 benign dermal and 61 malignant mucosal melanocytic tumors were examined for c-kit (KIT) expression. Sites of the mucosal melanomas were gingiva (not further specified; n = 30), buccal gingiva (n = 6), soft palate (n = 4), hard palate (n = 5), tongue (n = 7), lip (n = 6), and conjunctiva (n = 3). Melan A was expressed in all 14 dermal melanocytomas and in 59 of 61 (96.7%) tumors from oral or conjunctival mucosa, confirming melanocytic origin. C-kit receptor expression was strong and diffuse throughout the cytoplasm in all 14 dermal melanocytomas and was identified in basilar mucosal melanocytes over submucosal neoplasms (27 of 61, 44.3%), junctional (neoplastic) melanocytes (17 of 61, 27.9%), and, less commonly, neoplastic melanocytes of the subepithelial tumors (6 of 61, 9.8%). KIT expression anywhere within the resected melanomas correlated with significantly longer survival. These results suggest that c-kit receptor expression may be altered in canine melanomas and may have potential as a prognostic indicator for mucosal melanomas.     

犬常见肿瘤流行病学调查及组织病理学诊断

为探讨犬常见肿瘤的发病规律，试验收集哈尔滨地区2016-2017年宠物医院部分犬肿瘤病例71例，采用组织病理学方法对犬肿瘤进行病理学诊断，并对患病动物的品种、性别、年龄、发生部位和饮食情况与肿瘤发生关系进行统计分析。结果显示，71例确诊肿瘤病例中，恶性肿瘤28例，包括鳞状上皮细胞癌3例，基底细胞癌5例，乳腺癌14例，淋巴瘤2例，肾母细胞瘤、精原细胞癌、生殖细胞癌、侵袭性血管黏液瘤各1例；良性肿瘤43例，包括良性乳腺肿瘤15例，纤维瘤10例，平滑肌瘤5例，乳头状瘤和精原细胞瘤各3例，造釉细胞瘤、耵聍腺瘤、脂肪瘤、结节样增生、性索间质细胞瘤、颗粒细胞瘤、肛周腺瘤各1例。上述病例中，乳腺和皮肤是犬肿瘤的高发部位，分别占全部患犬的40.8%和34.0%；患病犬年龄1~16岁不等，平均发病年龄为9.1岁，7岁以后是肿瘤的高发期，中老年犬仍为主要发病群体，但低龄犬发病数量上升；各品种犬均可发生肿瘤，其中杂种犬发病率最高，其次是贵宾犬和京巴犬，且主要为乳腺肿瘤；饮食习惯主要以剩饭剩菜类和肉拌饭类为主，分别占患犬总数的39%和30%；部分肿瘤类型与犬的性别、是否绝育有关，如乳腺肿瘤多发生于未绝育的老年母犬。本研究结果为犬肿瘤的流行病学及诊断提供了参考依据，对犬肿瘤的预防和诊断有一定的借鉴意义。