Partial cranial internal hemipelvectomy in a feline patient with ilial osteosarcoma – a case report

A 15‐year‐old male domestic shorthair cat was presented with a mass over the left ilium. Computed tomography showed an osteolytic lesion originating from the left ilial wing with soft tissue invasion but no pulmonary metastasis. Cytology was consistent with a sarcoma, with axial osteosarcoma most likely. A partial cranial internal hemipelvectomy was performed, preserving the left pelvic limb and the caudal sacroiliac joint. Histopathology confirmed a poorly differentiated chondroblastic osteosarcoma with a mitotic count of 61 per 2.37 mm 2 . Surgical margins were clear, with a minimum 9‐mm tumour‐free margin. The cat recovered well, resumed normal activity by 3 weeks, and had no lameness. Adjuvant carboplatin chemotherapy was administered 20 days postoperatively and was continued for six cycles. Follow‐up thoracic radiographs at multiple intervals showed no metastasis, and pelvic radiographs at 6 months revealed no local recurrence or pelvic disruption. At 473 days postsurgery, the cat remained active and disease‐free. This case supports partial cranial internal hemipelvectomy as a viable option for feline ilial wing osteosarcoma.