Limbic encephalitis--an uncommon presentation of systemic malignancy.

A 46 years, nondiabetic, nonhypertensive woman presented with headache, vomiting, low grade intermittent fever, behavioral abnormality and seizures for last three months. Clinically she had meningism with bilateral papilloedema. Based on CSF analysis, normal CT scan of brain and suspicious lesion in X-ray chest, she was put on anti-tuberculosis therapy. As the patient further deteriorated clinically, MRI of brain was carried out and revealed bilateral increased signal intensities in both medial temporal lobes in T2 and flair sequences. Inj. acyclovir was added considering the diagnosis of herpes simplex encephalitis. In spite of receiving treatment patient gradually became more drowsy and repeat X-ray chest with CT guided FNAC showed picture of adenocarcinoma of lung. So finally, we concluded it to be a case of limbic encephalitis.