Sequential Photodynamic Therapy and Electrochemotherapy for Bilateral Palpebral Squamous Cell Carcinoma in a Cat: A Case Report
Tarcísio Guerra Guimarães, Karla Menezes Cardoso, Luciana Almeida Lopes, Carlos Roberto Daleck, Nuno Alexandre, Maria Filomena Botelho, Mafalda LaranjoABSTRACT
Objectives
To report the clinical outcomes of photodynamic therapy (PDT), alone and in combination with electrochemotherapy (ECT), in the conservative treatment of bilateral palpebral squamous cell carcinoma (SCC) in a cat, involving the right and left eyelids, with functional preservation and local tumor control.
Methods
A domestic shorthair cat with histologically confirmed squamous cell carcinoma affecting both eyelid margins underwent different therapeutic protocols. The left eye received a single PDT session with topical a lipophilic methyl ester derivative of 5‐aminolevulinic acid (160 mg/g) and red LED light, while the right eye received two sessions, followed by adjuvant ECT with intravenous bleomycin.
Results
The lesion in the left eye presented with pallor associated with mild inflammation after the PDT session, with complete resolution in the following days and recovery of its normal clinical appearance. In the right eye, the first two PDT sessions resulted in significant regression of the neoplastic lesions. However, a lesion in the medial canthus showed partial response, requiring adjuvant treatment with ECT, which led to complete clinical resolution, despite the presence of mild eyelid deformity.
Conclusions
In this single case report, PDT was associated with clinical regression of superficial lesions, while adjuvant ECT was followed by complete clinical resolution of the residual lesion. The combination of these modalities represents a viable conservative alternative to extensive surgical excision, enabling the tumor remission while preserving the aesthetic appearance and functional integrity of the eyelid.