Abstract Craniopharyngiomas are rare non-secretory epithelial sellar region tumors postulated to arise from embryonic remnants of Rathke’s pouch. Although histologically benign, these locally aggressive tumors pose significant challenges given proximity to visual pathways, hypothalamus, and pituitary regions. Typically, these present as multilobar cystic masses with/without solid component and their cystic fluid often has a characteristic “machine-oil” brown appearance. We present a unique case of an 18-month-old female with craniopharyngioma and elevated levels of AFP and βHCG in the cystic fluid. She presented with progressive vision loss with optic pallor and fixed dilated pupils. MRI brain showed a large suprasellar predominantly cystic mass with peripheral calcification. She underwent cyst decompression via an endonasal-transsphenoidal approach, fenestration of the cysts drained classic craniopharyngioma-appearing fluid. Due to intra-operative decompensation, no solid tumor was resected. Analysis of the cystic fluid showed raised AFP and βHCG of 11ng/ml and 352IU/L respectively, with negative serum and CSF markers. Given intracranial germ cell tumors (GCT) including choriocarcinoma can arise in similar location, a biopsy was performed. Biopsy showed Adamantinomatous Craniopharyngioma with multistratified squamous epithelium with peripheral palisading nuclei and calcification. Immunohistochemistry (IHC) confirmed beta-catenin nuclear reactivity with rare strongly βHCG- positive cells. No germ cell elements including syncytiotrophoblast or AFP positive cells were detected. Molecular testing including paired tumor-normal exome sequencing confirmed somatic CTNNB1 mutation. Postoperatively she recovered well and regained vision. Considering age and small residual tumor she was managed with observation only. Ten months later there is small growth of both solid and cystic components. Review of the literature shows presence of βHCG in craniopharyngioma cysts with two case reports of possible occurrence of collision tumors including craniopharyngiomas. This, however, is the first case to report high cyst fluid AFP levels with negative serum/CSF levels and absence of GCT, with child not warranting systemic therapy.
Brandt et al. (Fri,) studied this question.