Successful treatment of nasal planum haemangiosarcoma using electrochemotherapy in a cat

Abstract Haemangiosarcoma (HSA) is a malignant neoplasm originating from vascular endothelium. Its occurrence on the feline nasal planum is uncommon, with ultraviolet radiation considered a potential aetiologic factor. This case report highlights this unusual tumour's location and presents electrochemotherapy (ECT) as a novel and effective treatment. The cat received a single session of ECT with systemic bleomycin, resulting in complete tumour remission within 6 weeks. The patient was monitored for 236 days without recurrence of the treated lesion. During follow‐up, a cutaneous squamous cell carcinoma and another dermal HSA developed at different sites; both were successfully treated with the same ECT protocol. ECT demonstrated effectiveness in treating nasal planum HSA in cats, offering a promising option for managing this less common presentation. Long‐term monitoring is advised, as additional lesions may develop in areas exposed to ultraviolet radiation.