Specifically, can a desmoid tumor be found in the brain?

No: Desmoid tumors are tumors that arise from cells called fibroblasts. Fibroblasts are found throughout our body and their main function is to provide structural support and protection to the vital organs. They are, nonmalignant neoplasms that show locally aggressive growth but lack the potential to metastasize. Common sites: abdomen, pelvis. They can rarely occur in the head but not the brain.

Very Rare: Desmoid tumors do not arise directly in the brain, however, these tumors can rarely occur intracranially, meaning inside the skull. This has been reported most often in children with an inherited condition called fap (familial adenomatous polyposis). Desmoids in location mag be impossible to remove and can gtow back after surgery so treatment usually includes chemotherapy and/or radiation