A female patient with breast cancer presenting with altered sensorium. The following MRI suggests:: (A) Herpes simplex encephalitis, (B) Gliomatosis cerebri, (C) Limbic encephalitis, (D) Metastasis
Answer is C. The epidemiology of limbic encephalitis mimics that of the underlying malignancy. Tumours which can result in limbic encephalitis include: small cell carcinoma of the lung (classic cause); testicular germ cell tumors; thymic tumours; breast cancer; ovarian carcinoma; haematologic malignancies; gastrointestinal malignancie Clinical presentation: Clinical presentation typically causes sho-term memory loss and mental status changes. Seizures and psychosis have also been repoed . Radiographic features: MRI: High T2 signal without enhancement. Appearance is similar to herpes simplex encephalitis, and changes are most evident in the mesial temporal lobes. Bilateral involvement is most common (60%). PET scan: Can show increased FDG uptake . Differential diagnosis: Herpes simplex encephalitis - acute time course, presence of fever.