Multimodal treatment of canine lower eyelid mast cell tumours: lip-to-lid reconstruction and sentinel lymph node mapping in two cases.

Abstract

BACKGROUND: Mast cell tumours are the most common skin neoplasms in dogs, accounting for up to 21% of all cutaneous tumours. They typically appear as firm nodules, most often on the trunk, limbs, or head, and their biological behaviour depends on the grade. Diagnosis is based on cytology and histopathology, while surgical excision with adequate margins remains the treatment of choice, often requiring reconstructive techniques in anatomically sensitive areas, such as the eyelid. CASE PRESENTATION: The article describes two cases of lower eyelid mast cell tumours in dogs, surgically treated using the lip-to-lid technique with lymphadenectomy of the sentinel lymph node. This method allowed complete excision while preserving eyelid function and appearance. Histopathology revealed different tumour grades, resulting in distinct prognoses and postoperative strategies regarding adjuvant chemotherapy. In both cases the final outcome was positive, with no local reoccurrence or distant metastases. CONCLUSIONS: The use of lip-to-lid technique can be successfully used for the reconstruction of the lower eyelid defect after mast cell tumour removal. Sentinel lymph node mapping plays an essential role in perioperative staging for these tumours, and provides crucial information about prognosis. Multimodal approach for diagnosis and treatment of mast cell tumours is important to achieve a good long-term outcome. These cases contribute to the limited literature on lower eyelid mast cell tumours and support the integration of advanced staging techniques, including sentinel lymph node mapping, with reconstructive surgery in the management of periocular MCTs.