Papillary craniopharyngioma following an initial diagnosis of Rathke cleft cyst: a case report and narrative review

A 59-year-old man presented with a giant suprasellar cystic lesion causing obstructive hydrocephalus. Radiological and intraoperative findings suggested a cystic craniopharyngioma (CP); however, histopathology was interpreted as most consistent with a Rathke cleft cyst (RCC). Six years later, surveillance imaging demonstrated recurrence as a new mixed solid-cystic suprasellar mass with infundibular thickening. Histopathology showed papillary architecture with diffuse BRAF V600E immunopositivity, confirming papillary craniopharyngioma (PCP). The original specimen was subsequently re-examined, finding positivity for BRAF V600E staining and microscopic features supporting the diagnosis of PCP rather than RCC. We conducted a narrative review of published cases describing diagnostic overlap between RCC and CP. Several reports describe lesions with mixed histological features and cases initially labeled as RCC that were later reclassified as CP following additional sampling or modern molecular testing. Notably, nearly all such cases involved PCP rather than adamantinomatous CP. These observations suggest that some lesions initially diagnosed as RCC may represent under-recognized PCP, although a biological relationship between the 2 entities cannot be excluded. This case underscores the importance of integrating radiological, operative, and pathological findings when evaluating suprasellar cysts, additionally, the value of pathological reassessment-particularly BRAF V600E testing-when a presumed RCC demonstrates atypical features or interval progression.