Chemical meningitis is a medical condition characterised by sterile meningitis that usually develops in certain patients after neurosurgical procedures. Its acute clinical course and standard laboratory findings are indistinguishable from those of bacterial meningitis.
A case who presented with clinico-investigatory profile suggestive of acute bacterial meningitis. Patient showed good response to standard antibiotics and steroids, but deteriorated on stopping steroids. MRI brain showed hyperintense signal in the frontal horns of lateral ventricle on T1 weighted images suggesting presence of fat. MRI spine confirmed presence of ruptured teratoma in lumbo-sacral region which had caused chemical meningitis. Patient responded well to steroid therapy. Tumour histopathology confirmed the diagnosis of mature cystic teratoma 1).