Surgical treatment of epibulbar melanocytomas by complete excision and homologous corneoscleral grafting in dogs: 11 cases

Objective The aim of the study was to evaluate the efficacy, outcome, and complications following penetrating sclerokeratoplasty and frozen homologous corneoscleral grafting for the management of extensive canine epibulbar melanocytomas. Methods Medical records of canine patients treated at three different veterinary hospitals between 1999 and 2010 were reviewed. Signalment, location and extent of melanocytomas, recurrence rate, and early and late complications were reported. Patients were re‐examined postoperatively to provide follow‐up information. Results Patients included one intact male, three castrated males, six intact females, and one spayed female, with a median age of 5 years (range, 3–9). German Shepherds were overrepresented. Tumors extended from 2 to 4 clock hours at the limbus and up to 17 mm from clear cornea to globe equator. One case showed iridocorneal angle invasion; corneal involvement was present in all cases, and lipid keratopathy was present in four cases. In two cases, there was incomplete resection owing to tumor extent. Follow‐up time ranged from 3 to 72 months (median, 17 months), with one case of intraocular tumor progression. Early complications included anterior uveitis (11/11), intracameral fibrin (5/11), hyphema (4/11), corneal edema (4/11), exuberant corneal granulation tissue (2/11), focal retinal edema (1/11), dyscoria (1/11), and partial suture dehiscence (1/11). Late complications included corneal fibrosis and/or pigmentation (11/11), faint anterior cortical cataracts (3/11), and lipid keratopathy (1/11). Vision was retained in all cases. Conclusions This technique offers a surgically challenging but effective treatment for extensive epibulbar melanocytomas. In this case series, complications were mild and transient, with preservation of ocular anatomy and function.     

Adjuvant Electrochemotherapy Increases Local Control in a Recurring Equine Anal Melanoma

A 25-year-old gelding sport horse was referred for the treatment of recurring bilateral anal amelanotic melanoma. On physical examination, the horse presented bilateral poorly delimited perianal masses that recurred 2 months after surgical excision. The owner elected the lesions to be treated with surgery combined with electrochemotherapy using the drug cisplatin. The two masses were removed, and the surgical bed was treated with electrochemotherapy. A second session was performed 3 weeks later. The horse remained disease-free for 5 months and then experienced a marginal recurrence in one side. The nodule was re-treated, and the horse remained disease-free for 2 additional months, when it died of abdominal metastases. Electrochemotherapy can be added to the current strategies to palliate recurrent melanomas in horses.     

Antiproliferative Activity of Cyanophora paradoxa Pigments in Melanoma,Breast and Lung Cancer Cells

The glaucophyte Cyanophora paradoxa (Cp) was chemically investigated to identify pigments efficiently inhibiting malignant melanoma, mammary carcinoma and lung adenocarcinoma cells growth. Cp water and ethanol extracts significantly inhibited the growth of the three cancer cell lines in vitro, at 100 µg·mL⁻¹. Flash chromatography of the Cp ethanol extract, devoid of c-phycocyanin and allophycocyanin, enabled the collection of eight fractions, four of which strongly inhibited cancer cells growth at 100 µg·mL⁻¹. Particularly, two fractions inhibited more than 90% of the melanoma cells growth, one inducing apoptosis in the three cancer cells lines. The detailed analysis of Cp pigment composition resulted in the discrimination of 17 molecules, ten of which were unequivocally identified by high resolution mass spectrometry. Pheophorbide a, β-cryptoxanthin and zeaxanthin were the three main pigments or derivatives responsible for the strong cytotoxicity of Cp fractions in cancer cells. These data point to Cyanophora paradoxa as a new microalgal source to purify potent anticancer pigments, and demonstrate for the first time the strong antiproliferative activity of zeaxanthin and β-cryptoxanthin in melanoma cells.     

MIB‐1 immunoreactivity correlates with biologic behaviour in canine cutaneous melanoma

The growth fraction of 68 canine cutaneous melanomas was determined by immunostaining with MIB‐1, a monoclonal antibody to a Ki‐67 epitope that recognizes all proliferating cells. Fifty tumours were classified histologically as benign and 18 as malignant. The Ki‐67 proliferative index (percentage of positive cells over 500 neoplastic cells) was low (< 15%) in 55 cases and high ( 15%) in 13 cases. High Ki‐67 proliferative index and histological malignancy were both associated with significantly poorer 2‐year survival (P < 0.0001). However, the predictive value of the Ki‐67 proliferative index (97%) was higher than the predictive value of classical histology (91%). The evaluation of the growth fraction by the Ki‐67 proliferative index is highly predictive of the biological behaviour of canine cutaneous melanoma.     

Primary corneal malignant melanoma in a horse

A 13-year-old Missouri Fox Trotter gelding of chestnut colour was referred for a 6-week history of blepharospasm and epiphora of the left eye. Due to the presence of irregular corneal masses, superficial keratectomy was performed along with adjunctive strontium-90 beta irradiation and subsequent topical mitomycin C chemotherapy. A diagnosis of poorly melanised malignant melanoma was made based on histopathological examination and immunohistochemistry. There has been no recurrence of the neoplasm over 10 months of follow-up. To the authors' knowledge, this is the first documented case of a primary corneal melanocytic neoplasm in a horse.     

mTERT和mTyr双启动子联合调控HN基因重组腺病毒对B16动物模型的抑瘤作用

为探讨双启动子调控HN基因重组腺病毒Ad-mTERTp-mTyrp-HN对小鼠黑色素瘤动物模型的抑瘤作用,试验构建B16裸鼠皮下移植瘤模型,采用HEK293细胞扩增重组腺病毒,进行纯化和滴度检测。将重组腺病毒Ad-HN、Ad-mTERTp-HN、Ad-mTyrp-HN、Ad-mTERTp-mTyrp-HN、Ad-GFP和PBS通过尾静脉注射裸鼠,冰冻切片观察裸鼠肿瘤内GFP绿色荧光表达情况,通过肿瘤生长和裸鼠存活情况计算抑瘤率,探究其在体内的抗肿瘤作用。结果显示:重组腺病毒在HEK293细胞中扩增,滴度分别为10^11.250,10^12.250,10^10.625,10^12.125,10^12.250 TCID50/mL;肿瘤组织中能观察到黑色素细胞,证明皮下黑色素移植瘤模型构建成功;重组腺病毒对脏器无损伤,且在双启动子组脏器中没有观察到黑色素细胞的肝肺转移;通过尾静脉注射重组腺病毒后能够在肿瘤中观察到荧光表达;与其他组相比双启动子组重组腺病毒不但能抑制黑色素瘤的生长,而且能延长裸鼠的生存期,抑瘤率为55.5%。因此,该重组腺病毒Ad-mTERTp-mTyrp-HN具有靶向性,并且可以抑制肿瘤生长,可为黑色素瘤的治疗提供参考。     

Intraocular signet-ring cell melanoma in a hamster (Cricetulus griseus)

A two‐and‐a‐half year‐old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet‐ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters.     

Hypofractionated radiation therapy of oral melanoma in five cats

Five cats with melanoma involving the oral cavity were treated with hypofractionated radiation therapy (RT). Cobalt photons were used to administer three fractions of 8.0 Gray (Gy) for a total dose of 24 Gy. Four cats received radiation on days 0, 7, and 21 and one cat received radiation on days 0, 7, and 13. One of the cats received additional irradiation following the initial treatment course. Two cats received chemotherapy. Their age ranged from 11 to 15 years with a median age of 12 years. Three cats had a response to radiation, including one complete response and two partial responses. All five cats were euthanized due to progression of disease, with one cat having evidence of metastatic disease at the time of euthanasia. The median survival time for the five cats was 146 days (range 66-224 days) from the start of RT. The results of this study suggest that oral melanoma in cats may be responsive to hypofractionated RT, but response does not seem to be durable.     

Use of nested polymerase chain reaction (PCR) for detection of retroviruses from formalin-fixed, paraffin-embedded uveal melanomas in cats

Thirty-six formalin-fixed, paraffin-embedded enucleated globes from cats with a diagnosis of diffuse anterior uveal melanoma were obtained. Sections of tumor were excised, deparaffinized, and subjected to nested polymerase chain reaction (PCR) to identify proviral DNA sequences from the feline leukemia virus (FeLV)–feline sarcoma virus (FeSV; 36 eyes), and the feline immunodeficiency virus (FIV; 18 eyes). All samples tested were negative for FIV DNA. Three samples were positive for FeLV–FeSV DNA. This is the first reported evidence of a possible link between naturally occurring feline anterior uveal melanoma and the presence of FeLV–FeSV DNA.     

Role of selection and inbreeding on the incidence of cutaneous malignant melanoma in Sinclair swine

Summary This paper reports the quantitative analysis of the historical database of a herd of Sinclair swine affected by cutaneous malignant melanoma. The herd was under partial and non-systematic selection for melanoma susceptibility (animals having at least one tumour during the first 6 weeks of life). Weighted selection differentials for the number of tumours at birth and the number of tumours at 6 weeks were generally positive and between −0.43 and 4.76 tumours for the number of tumours at 6 weeks. Estimates of the heritability for number of tumours at birth and at 6 weeks using 1934 animals were 0.27 (±0.03) and 0.25 (±0.03), respectively. The estimate of the genetic correlation between these two traits was 0.95 (±0.03). Genetic trends were positive for the number of tumours at birth and at 6 weeks. In spite of positive selection differentials and a moderate heritability, there was a negative phenotypic trend in the number of tumours. Natural selection might be acting in a direction opposite to artificial selection in the Sinclair herd. The slopes of the regression of the number of tumours at birth, at 6 weeks, and melanoma susceptibility on individual inbreeding coefficients were non-significant, indicating no evidence of dominance. The number of live-born pigs was lower in litters from parents susceptible to the disease (p < 0.01).