BackgroundIntradural lipomas have been previously reported in individuals with spinal dysraphism; however, they have not been reported in cats with an intact spinal canal. Desmoid tumors are a rare finding in veterinary medicine, and there is no prior description of these tumors invading the spinal cord. Furthermore, the etiopathogenesis remains debated, with trauma, such as surgical intervention of an intradural structure, potentially contributing to its development.Case descriptionA 10-month-old domestic shorthair cat was presented initially with progressive proprioceptive ataxia. The MRI identified an intradural compressive lesion at the cranio-cervical junction, confirmed as a lipoma by histopathology. Despite surgical removal, postoperative complications led to the cat's euthanasia. Postmortem examination revealed invasion of a desmoid tumor at the surgical site.ConclusionsThis case highlights the rarity of intradural lipomas in this location and the unusual complication of desmoid tumor invasion. It underscores the need for further research into the underlying mechanisms and potential diagnostic and therapeutic strategies for similar cases and suggests that these findings may be added to the list of potential post-surgical complications.