The association of ectopic craniopharyngioma in the fourth ventricle with familial adenomatous polyposis: illustrative case

Cerebellopontine angle craniopharyngioma in familial adenomatous polyposis

Background

Craniopharyngiomas are benign tumors arising in the sellar and suprasellar regions. Although ectopic tumors do occur, it is usually due to local spread or recurrent tumors. Purely ectopic cerebellopontine angle (CPA) or 4th ventricle tumors are extremely rare and have been found to be significantly associated with familial adenomatous polyposis (FAP), a genetic disorder.

Case Description

Only four cases of ectopic CPA craniopharyngioma associated with FAP have been reported to date. Here, we present the 5th case of ectopic CPA craniopharyngioma on a background of FAP. The previously described cases have been elaborated as well.

Conclusion

CPA tumor with a background of FAP should raise a differential diagnosis of craniopharyngioma, and similarly, a CPA primary ectopic craniopharyngioma may raise suspicion of underlying APC gene mutation.

Isolated fourth ventricle craniopharyngioma: Representative case illustration and review of literature

Background

Sella and suprasellar areas are frequently affected by craniopharyngiomas. In this article, eight occurrences have been documented. One is new, and the remaining seven are from previously published articles. Their prevalence in the posterior fossa without expansion from the suprasellar area is unusual.

Case Description

We present a case of a primary 4th ventricular craniopharyngioma of the posterior fossa in a 16-year-old male with no association with Gardner's syndrome. He presented with sudden deterioration of consciousness level and was diagnosed as having a homogeneously contrast enhancing lesion occupying the 4th ventricle with obstructive hydrocephalus. The patient underwent emergency placement of external ventricular drain followed by complete removal of the tumor on the next day by midline suboccipital craniotomy with telovelar approach. Histopathological features were consistent with the adamantinomatous variety of craniopharyngioma. He had complete neurological recovery and no evidence of tumor recurrence in 1-year follow-up.

Conclusion

The craniopharyngioma in our case was distinct because it was a solid tumor with no cystic component, exhibited homogeneous contrast enhancement in neuroimaging, developed in the fourth ventricle, and reached the level of foramen magnum, features that had rarely been documented previously. We also reviewed the literature on reported cases of 4th ventricular craniopharyngioma to strengthen knowledge in this area and highlight the embryological basis of ectopic craniopharyngioma.