Ectopic craniopharyngiomas

Abstract

Craniopharyngiomas (CPs) are rare embryonic malformational tumours of the sellar/parasellar region, classified by the World Health Organization (WHO) 5th edition as grade 1 tumours. They may arise anywhere on the path of embryonic cell migration between the midline sphenoid bone and the floor of the sella turcica. On rare occasions, they can be found remotely in areas like the nasopharynx, the orbit, the posterior fossa, the brain parenchyma and the spine. Such ectopic CPs may present as primary in an atypical location, or as secondary, which represent distant recurrence after initial surgical excision in an orthotopic location. The pathogenesis of primary and secondary ectopic CPs is considered distinct, reflecting differences in developmental biology versus tumour dissemination. Primary ectopic CPs are thought to arise either from embryologically misplaced tissue or from genetically driven tumourigenesis outside the sella. Pathogenesis of secondary ectopic CPs reflects tumour cell dissemination through surgical tract implantation, cerebrospinal fluid (CSF) seeding or meningeal seeding. Ectopic cases pose unique diagnostic and therapeutic challenges. In this review which encompasses 97 cases (42 primary and 55 secondary ectopic CPs) published during the period, 2000–2025, we discuss the pathogenesis, clinical presentation, diagnosis and management of these distinctive tumours.