Multiple limbal haemangiosarcomas in a border collie dog: management by lamellar keratectomy/sclerectomy and strontium-90 beta plesiotherapy

Surgical treatment of conjunctival hemangioma and hemangiosarcoma: A retrospective study of 52 dogs

OBJECTIVE

To review cases of canine conjunctival hemangioma (HA) and hemangiosarcoma (HSA) treated surgically at a referral center to establish success of surgical management, recurrence rates, and long-term outcomes for patients.

ANIMALS STUDIED

Retrospective record review of dogs that underwent surgery to remove histologically diagnosed conjunctival HA or HSA between April 2004 and April 2020 to collect data on signalment, tumor location, interval between initial presentation and surgery, tumor diagnosis, surgical dose, surgical margins, tumor size, recurrence and survival times.

RESULTS

A total of 52 dogs (60 tumors) were included. The mean age of affected dogs was 8.69 years; the most affected breed was the Border collie (n = 13, 25%). 28 tumors were HA (46.67%) and 32 HSA (53.33%). Tumors occurred in three locations: the lateral bulbar conjunctiva (n = 37, 61.67%), the third eyelid margin (n = 19, 31.67%), and the ventral conjunctival fornix (n = 4, 6.67%). There was no site predilection for HA versus HSA. 97% of tumors occurred in non-pigmented tissue. Corneal invasion was more likely to be a feature of malignant tumors. Five tumors were incompletely excised, one of which recurred. There was no statistical difference in likelihood of incomplete excision between HSA and HA. Six tumors (10%) recurred. HSA was not statistically more likely to recur than HA. Recurrence times ranged from 5 weeks to 1 year.

CONCLUSION

Surgical treatment of conjunctival HA and HSA is likely to be curative. There is a recurrence rate of 10% regardless of tumor type, and recurrence may be late in the course of the disease.

Angioceratoma conjuntival canino: relato de caso

RESUMO O angioceratoma é um tumor de origem vascular, semelhante ao hemangioma, que se diferencia deste por alterações histológicas epiteliais. A apresentação ocular do angioceratoma é pouco frequente em cães, sendo mais comum a ocorrência de hemangioma e hemangiossarcoma. Neste relato, é descrito o caso de um cão, macho, da raça Border Collie, que apresentava uma massa localizada, hiperêmica, bem vascularizada e protrusa, na região temporal da conjuntiva bulbar do olho direito (OD). Foi realizado exame oftalmológico completo e ultrassonografia ocular, tendo sido possível observar que a massa não envolvia outras estruturas oculares além da conjuntiva. Dessa forma, foi realizada a conjuntivectomia parcial, e o material foi encaminhado para análise histológica. O exame histopatológico foi conclusivo para um angioceratoma e mostrou que as margens da amostra estavam livres. O procedimento cirúrgico com margem de segurança foi eficiente no tratamento da neoplasia, sem recorrência até o momento do presente relato.

Marginal resection and adjuvant strontium plesiotherapy in the management of feline eyelid malignant peripheral nerve sheath tumours: two cases

Case series summary

Two cats with a marginally resected eyelid malignant peripheral nerve sheath tumour were treated with adjuvant strontium plesiotherapy a few weeks after surgery. The dose applied in both cases was 200 Gy to the surface, in five fractions, on a Monday–Wednesday–Friday basis. The treatment aimed to achieve a clinical margin of approximately 1 cm around the surgical scar and multiple application fields were required to cover such an area. Local recurrence was not seen in either case after 1330 and 645 days, respectively.

Relevance and novel information

The majority of periocular malignant peripheral nerve sheath tumours reported in the literature recur after surgery. In the two cases described in this report the combination of surgery and adjuvant plesiotherapy has been able to provide good local control with minimal toxicity. This multimodal approach could be considered as an alternative to aggressive surgery such as enucleation or exenteration.

Principles and Applications of Radiation Therapy in Exotic Animals

Radiation therapy is a treatment modality for cancer that is widely used in veterinary medicine, although its use in exotic animal practice has remained limited. However, there are case reports and case series of treating birds, small mammals, and reptiles for a variety of cancers with radiotherapy with varied outcomes. In this article the basic principles of radiation therapy are reviewed and the literature regarding its use in exotic animal practice is summarized. Side effects of radiotherapy are also discussed.

Management of canine corneal squamous cell carcinoma with lamellar keratectomy and strontium 90 plesiotherapy: 3 cases

PURPOSE

To report three cases of canine corneal squamous cell carcinoma (SCC) treated with strontium 90 beta radiation as an adjunct to surgical excision.

METHODS

Corneal SCC was excised with lamellar keratectomy. This was followed by local application of strontium 90 beta radiation.

RESULTS

Available case follow-up times range from 3 to 50 months. One case suffered a recurrence 5 months following initial excision and strontium 90 treatment.

CONCLUSION AND DISCUSSION

Strontium 90 beta radiation has been used extensively as an adjunctive treatment for equine corneal SCC and in other canine ocular tumors; however, there is a paucity of information regarding use in canine corneal SCC. The cases presented here suggest its use following keratectomy may be helpful in preventing disease recurrence. At the dosage used, severe adverse effects were not observed.

Pollakiuria and stranguria in a Labrador retriever with penile HSA

An approximately 8 yr old castrated male Labrador retriever presented for evaluation of weight loss, stranguria, and pollakiuria. Lysis of the proximal one-third of the os penis was diagnosed on abdominal radiographs, and a positive contrast urethrography revealed a smoothly marginated filling defect along the dorsal aspect of the urethra at the level of the radiographically observed osteolysis. Regional ultrasound revealed an echogenic mass at the proximal aspect of the os penis with a severely irregular and discontinuous periosteal surface. A penile hemangiosarcoma (HSA) was confirmed on histopathologic evaluation after a penile amputation and scrotal urethrostomy were performed. Although HSA is a common malignant neoplasm in dogs, lysis of the os penis has not previously been documented. Adjunctive chemotherapy, although recommended, was declined, and the patient survived 236 days postoperatively. That survival time is considerably longer than the average survival time for patients with HSA, other than cutaneous forms of HSA. Although an uncommon presentation, HSA of the penis should be considered a differential diagnosis in older canines with signs of lower urinary tract disease, especially in breeds that have been documented to be predisposed to HSA.

Immunohistochemical Characteristics of Normal Canine Eyes

Immunohistochemistry is widely utilized in diagnostic laboratories to study neoplastic and nonneoplastic diseases. Knowledge of the immunohistochemical characteristics of normal tissue is essential for interpretation of immunoreactivity in pathologic conditions. In this study, immunohistochemistry was performed with a broad panel of diagnostically relevant antibodies on 4 normal canine globes—namely, vimentin, pan-cytokeratin (AE1/AE3), cytokeratin 7, cytokeratin 8/18, cytokeratin 20, α–smooth muscle actin, muscle specific actin, desmin, Melan-A, microphthalmia transcription factor, S-100, glial fibrillary acidic protein, triple neurofilaments, neuron-specific enolase, chromogranin A, synaptophysin, laminin and CD31. Results include cytokeratin immunoreactivity limited to the conjunctival epithelium, corneal epithelium, and retinal pigment epithelium; distinct patterns of immunopositivity of muscle markers; and widespread immunoreactivity for vimentin and most neural/neuroendocrine markers. These findings in normal eyes provide the basis for interpretation of ocular immunohistochemistry in dogs. Published immunophenotypes of primary ocular neoplasms are also reviewed.

Efficacy of doxorubicin-based chemotherapy for non-resectable canine subcutaneous haemangiosarcoma

Eighteen dogs with measurable subcutaneous haemangiosarcoma (SQHSA) were treated with doxorubicin-based chemotherapy. Response assessment was evaluated and compared using World Health Organization (WHO), Response Evaluation Criteria in Solid Tumours (RECIST) and tumour volume criteria. The overall response rate for all dogs was 38.8% using WHO criteria, 38.8% using RECIST criteria and 44% using tumour volume criteria. One dog had a complete response. The median response duration for all dogs was 53 days (range 13-190 days). Four dogs had complete surgical excision after neoadjuvant chemotherapy. The median progression-free interval for dogs with complete surgical excision after neoadjuvant chemotherapy was significantly longer than those not having surgical excision (207 days versus 83 days, respectively) (P = 0.003). No significant difference in metastasis-free interval or survival time was found between the groups. Doxorubicin-based chemotherapy appears to be effective for non-resectable canine SQHSA, although the response duration is relatively short.