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

Computed Tomography Image Analysis and Clinical Diagnosis Value of Nasal Olfactory Neuroblastoma

BACKGROUND

This article retrospectively analyzed the data of all patients diagnosed with malignant tumors of the nasal cavity and sinuses by pathologic section in all patients (including outpatients and inpatients) in our hospital from January 2008 to December 2017 (10 years) to discuss the nasal cavity The clinical characteristics of sinus malignant tumors and the clinical characteristics (symptoms, signs, imaging examinations) of 35 cases of olfactory neuroblastoma with high incidence were analyzed, and their treatment methods and prognosis were summarized for future nasal tumors.

CLINICAL BASIS FOR PREVENTION AND TREATMENT

In our department, 300 cases of malignant tumors of nasal cavity and sinuses were treated within 10 years. AGE: Eighty-six cases (28.6%) were in the age group 50-59 years old, occupying first place, and 55 cases (18.3%) were in the age group 60-69 years old, occupying second place. By comparing groups A and B with malignant tumors of the nasal cavity and sinuses, the difference in age distribution of olfactory neuroblastoma is statistically significant. Of the 35 cases of olfactory neuroblastoma, 23 cases were diagnosed with nasal tumors on admission, 12 cases were initially diagnosed with nasal polyps (including 7 cases with hemorrhagic and necrotic nasal polyps), and 20 cases underwent rapid pathologic definite diagnosis during the operation.

DIAGNOSIS FOR POSTOPERATIVE PATHOLOGIC RETURNS

On the basis of our analysis, the following conclusions can be drawn: Of the 300 cases of malignant tumors of the nasal cavity and paranasal sinuses, age distribution tends to be younger, the overall incidence of males is higher than that of females, but the proportion of male and female olfactory neuroblastoma is equal, and the incidence of adenoid cystic carcinoma and sarcoma. The morphology of cancer can be divided as follows: the tissue source is epithelial tissue, the cancer is harder, paler, drier, and often forms cancer nests, the parenchymal and interstitial boundaries are clear, and the fibrous tissue is hyperplastic. The incidence rate of females is higher than that of males, with the primary origin in the sinuses. Among them, the maxillary sinus is more common. Olfactory neuroblastoma, lymphoma, and sarcoma are gradually increasing in malignant tumors of the nasal cavity and sinuses.

Limbic Encephalitis as a Presenting Complication for Small Cell Lung Cancer

Limbic encephalitis (LE) is a rare neurological paraneoplastic complication that occurs secondary to malignant tumors. It is commonly presented as refractory seizures that are resistant to most anti-epileptics. We are presenting a unique case of small cell lung cancer complicated with LE. The challenging part of our case is that the patient had a history of seizure disorder in the past, and she was treated initially as an anti-epileptic treatment failure. A 68-year-old patient with a history of epilepsy was admitted to the ICU with resistant status epilepticus (SE), and respiratory failure secondary to pneumonia. Further workup revealed that the patient has small cell lung carcinoma. An extensive workup done to investigate resistant seizures revealed that she had a rare type of paraneoplastic autoantibodies (Anti-Hu) in the cerebrospinal fluid, which supported the diagnosis of the paraneoplastic autoimmune LE. High dose steroids helped to decrease the seizures episodes, but the family decided to proceed with palliative measures only at the end. Diagnosing LE requires ruling out other common causes of SE. Treatment options include treating underlying cancer as well as means of immunosuppression or antibody removal by tacrolimus and cyclophosphamide and even intravenous immunoglobulin (IVIG) or plasma exchange. It is important to consider LE in the differential diagnosis when managing patients with resistant SE in the ICU, even if the brain imaging and cerebrospinal fluid (CSF) analysis were within normal limits.