title: Abscess formation associated with pituitary adenoma: A case report: Changes in the MRI appearance of pituitary adenoma before and after abscess formation.
abstract: BACKGROUND
  Pituitary abscess is an extremely rare finding. The abscess may arise as a primary pituitary lesion or be associated with parasellar pathology. It is important for pituitary abscess treatments to perform early diagnosis. In this report, we describe a case of pituitary adenoma in which MRI findings changed during the follow-up period and strongly suggested progression to pituitary abscess arising from adenoma.
  
  
  METHODS
  In a 73-year-old female, pituitary adenoma had been incidentally detected; MRI showed typical findings of pituitary adenoma, and we had followed up the pituitary lesion and clinical symptoms. Six months later, she had oculomotor nerve palsy and symptoms of hypopituitarism. Hematological examination revealed inflammation and hypopituitarism. MRI showed striking changes in the signal intensity of the pituitary lesion, and strongly suggested occurrence of sinusitis and pituitary abscess ascribed to pituitary adenoma. She was admitted and endoscopic transsphenoidal surgery was performed. The sellar floor was destroyed, and yellowish-white creamy pus was observed. A histopathological study using hematoxylin-eosin staining showed adenoma and inflammatory cells. Aerobic, anaerobic, and fungal cultures were negative. Antibiotics were administered and hormonal replacement was started. Neurological and general symptoms were improved, and postoperative MRI revealed complete evacuation of abscess and removal of tumor.
  
  
  CONCLUSIONS
  Pituitary abscess within invasive pituitary adenoma is a rare entity, and shows high mortality. Early diagnosis of pituitary abscess is very important for the prompt surgery and initiation of treatment with antibiotics. In our case, changes in MRI findings were helpful to diagnose pituitary abscess, and endoscopic transsphenoidal surgery was an optimal surgical treatment.
authors.affiliation: Department of Neurosurgery, Yamagata University Faculty of Medicine, 2-2-2 Iidanishi, Yamagata City, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kuge
authors.forename: Shinya
authors.initials: S
authors.lastname: Sato
authors.forename: Sunao
authors.initials: S
authors.lastname: Takemura
authors.forename: Kaori
authors.initials: K
authors.lastname: Sakurada
authors.forename: Rei
authors.initials: R
authors.lastname: Kondo
authors.forename: Takamasa
authors.initials: T
authors.lastname: Kayama