Recurrent chemical meningitis in craniopharyngioma without reduction in size of cyst: case report of two cases and review of the literature.

Chemical meningitis is a rare phenomenon due to rupture of a craniopharyngioma cyst; it develops because of presence of cholesterol crystals in cyst fluid secreted by the squamous epithelium lining of the cyst. Spontaneous rupture of the cyst may present with or without meningitis, depending upon the cholesterol contents of cystic fluid of tumor. A decrease in the size of cyst may or may not be noted. Here we report two cases of craniopharyngioma, one which had a recurrent episode of chemical meningitis after surgery due to leak from residual component of the craniopharyngioma without evidence of recurrence of lesion, or decrease in the size of the cyst. Another case presented with initial symptoms and signs of meningitis, with no change in the size of the lesion after the second episode of chemical meningitis.