Tomokatsu Hori, Takakazu Kawamata, Kosaku Amano, Yasuo AIhara, Yosikazu Okada, Masami Ono and Nobuhiro Miki
Objective: Craniopharyngiomas pose a baffling problem to neurosurgeons because of the difficulty in total
removal and tendency to recur even operated by experienced hands. We propose a new classification or grading
system of craniopharyngiomas based on MRI findings including not only sagittal diameter but also coronal diameter of
the tumor, the usefulness of which was evaluated in 100 consecutive patients mainly operated by one neurosurgeon
(T.H.).
Methods: Between 1981 and 2012, 100 patients comprising 55 males and 45 females aged from 1 year to 75
years (mean 33.1 ± 22.7) underwent surgeries for craniopharyngiomas, including endoscopic removal in two patients.
Thirty-six pediatric (younger than 15 years) patients comprising 23 males and 13 females with a mean age of 8.1 ± 4.3
years were included. Surgeries were conducted by a transnasal transsphenoidal (TSR), pterional (PTR) or anterior
interhemispheric (AIH) approach, orbyendoscopic removal (END).Based on MRI findings with or without gadolinium
enhancement, tumor size was classified by the maximum sagittal diameter into <2 cm (score 1), 2-4 cm (score 2), and
>4 cm (score 3). Tumor size was also classified by the maximum coronal diameter perpendicular to midline into<2 cm
(score 1), 2-4 cm (score 2), and >4 cm (score 3).A score of 1 was added when the lower limit of the tumor was below
the clinoidal line, when the tumor extended to the mammillarybody, or when the tumor reached the foramen of Monro.
From MRI findings, tumor composition was classified as cystic only (score 0), multi-cystic (score 1), mixture of cystic
and solid (score 2), and solid only (score 3). In each patient, the total score was calculated and graded as follows:
score 2 as grade I, scores 3-5 as grade II, scores 6-8 as grade III, scores 9-11 as grade IV, and score 12 as grade V.
Results: Mean age was 35.6 ± 22.8 in grade II patients, 34.9 ± 22.8 years in grade III, 24.1 ± 20.6 in grade IV, and
1 year in grade V (1 patient).Although tumor grade was apparently higher in younger patients, there was no significant
difference. Higher grades were associated with lower pre- and postoperative performance status. Preoperative grade
was significantly lower in patients operated via the TSR compared to PTR or AIH approach.
Conclusion: The new grading system is useful for analyzing pre- and post-operative performance status, and for
selecting operative approach. It is also useful to compare treatment outcomes reported in the literature.