Postoperative intracranial seeding of craniopharyngiomas--report of three cases and review of the literature.

PURPOSE: Seeding of craniopharyngioma has been rarely reported. We present three cases that ectopically recurred with seeding along the surgical route and CSF spaces.

METHODS: The first patient was a 13-year-old boy who had initially undergone radical excision of a suprasellar and retrosellar craniopharyngioma by a right pterional approach. Postoperative MRI showed no evidence of residual tumor. Two years later, MRI revealed a local recurrence and in addition a separated cystic tumor on the right side adjacent to the middle cerebral artery consistent with seeding along the surgical route. Both tumors were removed by re-operation. On histopathological examination, both, the local recurrent tumor and the distant deposit turned out to be adamantinomatous craniopharyngiomas. The second patient was a 27-year-old woman who was operated on for the first time via a right pterional and 1 year later for a recurrent craniopharyngioma via a transsphenoidal approach. Two years later, MRI revealed a right fronto-lateral intracranial metastasis at the site of the former craniotomy, which was removed by re-craniotomy. This deposit in the operative pathway was found to be an adamantinomatous craniopharyngioma, as was the initial tumor. The third patient was a 42-year-old man who was operated on 10 years ago for the first time via a right fronto-temporal approach. The recent control MRT revealed a right parietal intracranial tumor with peripheral contrast enhancement, which was located distant to the former craniotomy. The tumor was removed and histopathological examination revealed an adamantinomatous craniopharyngioma in accordance with the initial tumor. Postoperatively, the three patients were neurologically intact.

CONCLUSION: Although craniopharyngiomas exhibit a benign histopathological pattern, cerebrospinal fluid seeding along the surgical route or along the CSF pathways has been observed. Ectopic recurrence of craniopharyngioma suggests that meticulous protection of the whole surgical field and careful handling of the tumor during the operation are required. It should be emphasized that long-term follow-up is mandatory, even in patients undergoing a total removal.