Prolactinoma with a high adrenocorticotropic hormone level caused by meningitis--case report.

A 69-year-old man was admitted semicomatose with high-grade fever and meningeal signs. Magnetic resonance imaging showed a supra- and intrasellar lesion. Hormone studies on admission showed increased serum prolactin, adrenocorticotropic hormone (ACTH), and cortisol titers. However, the serum ACTH and cortisol levels returned to normal after treatment of meningitis with an antimicrobial agent. The histological diagnosis was pituitary adenoma. Immunohistological staining showed positive reaction for prolactin but not for ACTH. This is a rare case of prolactinoma with a high serum ACTH level caused by meningitis.