title: Sequential pathological changes during malignant transformation of a craniopharyngioma: A case report and review of the literature.
abstract: BACKGROUND
  Malignant transformation of craniopharyngiomas is quite rare, and the etiology of transformation remains unclear. The prognosis of malignantly transformed craniopharyngiomas is very poor.
  
  
  METHODS
  A 36-year-old male had five craniotomies, five transsphenoidal surgeries, and two radiation treatments until 31 years of age after diagnosis of craniopharyngioma at 12 years of age. All serial pathological findings indicated adamantinomatous craniopharyngioma including those of a surgery performed for tumor regrowth at 31 years of age. However, when the tumor recurred approximately 5 years later, the pathological findings showed squamous metaplasia. The patient received CyberKnife surgery, but the tumor rapidly regrew within 4 months. The tumor was resected with the cavernous sinus via a dual approach: Transcranial and transsphenoidal surgery with an extracranial-intracranial bypass using the radial artery. Pathologic examination of a surgical specimen showed that it consisted primarily of squamous cells; the lamina propria was collapsed, and the tumor cells had enlarged nuclei and clarification of the nucleolus. The tumor was ultimately diagnosed as malignant transformation of craniopharyngioma. After surgery, he received combination chemotherapy (docetaxel, cisplatin, and fluorouracil). The tumor has been well controlled for more than 12 months.
  
  
  CONCLUSIONS
  Serial pathological changes of the craniopharyngioma and a review of the 20 cases reported in the literature suggest that radiation of the squamous epithelial cell component of the craniopharyngioma led to malignant transformation via squamous metaplasia. We recommend aggressive surgical removal of craniopharyngiomas and avoidance of radiotherapy if possible.
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Negoto
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Sakata
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Takachika
authors.initials: T
authors.lastname: Aoki
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Orito
authors.affiliation: Department of Pathology, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakashima
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Hirohata
authors.affiliation: Department of Pathology, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sugita
authors.affiliation: Department of Neurosurgery, Kurume University School of Medicine, Fukuoka, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Morioka
keywords: Craniopharyngioma; TPF chemotherapy; malignant transformation; squamous metaplasia