Low-grade mast cell tumor in dog: surgical approach andreconstruction using deep circumflex iliac axial flap

Mast cell tumors are common cutaneous neoplasms in dogs, and surgical treatment may require reconstructive techniques to close extensive defects. This study aimed to report the diagnostic and therapeutic management of a low-grade cutaneous mast cell tumor in a dog, emphasizing reconstruction using a deep circumflex iliac artery axial pattern flap and postoperative outcomes. A four-year- and threemonth-old neutered male mixed-breed dog presented with a nodule on the lateral aspect of the right pelvic limb. Fine-needle aspiration cytology revealed a round-cell neoplasm suggestive of a mast cell tumor. The patient underwent surgical tumor excision with a 3 cm lateral safety margin, combined with sentinel lymph node identification and excision, followed by reconstruction of the resulting defect using an axial pattern skin flap. Histopathological examination confirmed a low-grade cutaneous mast cell tumor, with tumor-free lateral surgical margins and metastasis to the popliteal lymph node. Although initial flap adaptation was satisfactory, ischemic necrosis developed in its distal portion on the fifth postoperative day. Healing by second intention was subsequently adopted, involving daily wound dressings and enzymatic debridement with collagenase, resulting in complete wound closure after 53 days. This case highlights the importance of histopathological evaluation, lymph node staging, and reconstructive surgical planning, as well as careful postoperative monitoring for the early identification and management of vascular complications.