Multimodality approach to a pediatric craniopharyngioma with mixed histological features.

Introduction: Pediatric craniopharyngiomas (CPG) are histologically benign but clinically complex tumors. Traditional mainstays of treatment include surgical resection and radiotherapy. Molecular insights report that children tend to have the adamantinomatous subtype that is driven by the CTNNB1 pathway while papillary CPGs prevalent in the adult population are characterized by BRAFV600E mutations. Mixed histological subtypes are rare. We report an unusual case of a pediatric CPG with both subtypes; and discuss the management strategies in corroboration with contemporary literature.

Case presentation: A 11-year-old female presented with symptoms of panhypopituitarism, optic atrophy and bitemporal hemianopia. Magnetic resonance imaging (MRI) brain demonstrated a lobulated cystic-solid sellar-suprasellar lesion. She underwent stereotactic aspiration of the lesion and insertion of an Ommaya reservoir. Intraoperative cyst fluid cytology confirmed wet keratin nodules, characteristic of adamantinomatous CPG. She underwent intracystic interferon-alpha therapy with good response for approximately 7 months. However, tumor progression was noted on subsequent MRI scans, with difficulty aspirating from the Ommaya reservoir. In view of this, the patient underwent an uneventful transsphenoidal resection of the tumor. Histology reported a craniopharyngioma with mixed adamantinomatous and papillary features with BRAFV600E positivity. MRI scans performed 2 months after surgery showed tumor recurrence. Decision was made for a trial of a dabrafenib-a BRAF inhibitor. After commencement of dabrafenib monotherapy for 1 month, radiological evaluation showed good tumor response. At 24 months post-treatment, the patient was well with her tumor in remission. In addition, no treatment-related adverse side effects were observed.

Conclusion: We report a unique case of pediatric craniopharyngioma with mixed histological features that was managed successfully via a multimodality approach. Emphases are on molecular profiling of the said lesion, minimizing permanent morbidity and maintenance of quality of life for a growing child. In the context of tumors with BRAFV600E mutations, the use of targeted therapy can be considered.