Paraneoplastic limbic encephalitis associated with mixed olfactory neuroblastoma and craniopharyngioma: A case report and literature review.

Rationale: Paraneoplastic limbic encephalitis (PLE) is a rare disorder of the nervous system associated with malignant disease. It has a subacute onset with the following symptoms: cognitive dysfunction, seizures, irritability, hallucinations, and short-term memory loss. Herein, we report the case of a 35-year-old man with PLE, an olfactory neuroblastoma (ONB) admixed with craniopharyngioma, and serum anti-Hu antibodies.

Patient Concerns: The patient presented with generalized seizures, short-term memory loss, and a polypoid mass located high in the nasal cavity.

Interventions: He underwent surgical resection of the tumor and postoperative chemoradiotherapy with concurrent intra-arterial cisplatin administration.

Diagnosis: Pathological examination indicated an ONB admixed with craniopharyngioma.

Outcomes: The patient's neurological symptoms gradually diminished after surgery. No evidence of recurrence was observed during a 4-year follow-up.

Lessons: We reported a histologically unusual heterogeneous tumor that comprised ONB and craniopharyngioma. This is the first reported case of PLE with anti-Hu antibodies possibly associated with ONB admixed with craniopharyngioma.