Misdiagnosis of elevation of β-hCG in cystic craniopharyngioma: illustrative case

BACKGROUND: Craniopharyngiomas and germ cell tumors (GCTs) are both rare intracranial tumors commonly present in childhood or middle age. They share similar clinical and radiological features. GCTs commonly give rise to tumor markers in the cerebrospinal fluid, hence guiding the treatment plan. OBSERVATIONS: This article reports the case of a 5-year-old boy with a large sellar and suprasellar mass with obstructive hydrocephalus. Laboratory studies showed increased beta-human chorionic gonadotrophin (β-hCG) levels in the cystic fluid, suggestive of choriocarcinoma. He underwent 3 cycles of chemotherapy but showed a poor response. Further aspiration followed by tumor debulking was performed, and histopathological examination revealed craniopharyngioma. LESSONS: This case report indicates that β-hCG, commonly regarded as a specific tumor marker for choriocarcinoma, is detectable in other forms of suprasellar tumors. The authors highlight clinical and radiological features of suprasellar tumors that can be misdiagnosed as intracranial GCTs. The relevance of tumor markers and indications for histopathological confirmation are discussed.